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Monitoring of Eastern Fox Snakes (Pantherophis gloydi)in Response to Habitat Restoration

at Sterling State Park in Southeast Michigan

Prepared by:Yu Man Lee

Michigan Natural Features InventoryP.O. Box 30444

Lansing, MI 48909-7944

For:Michigan Department of Natural Resources

Parks and Recreation DivisionState Park Stewardship Program

P. O. Box 30031Lansing, MI 48909

October 3, 2006

Report Number 2006-17

Cover photo identification and credits:Top left: Sterling State Park, Campground Restoration Unit, photo by Yu Man LeeTop right: Sterling State Park, Interpretive Kiosk Unit, photo by Nathan HerbertCenter: Eastern Fox Snake, photo by Yu Man Lee

Recommended Citation:Lee, Y. 2006. Monitoring of Eastern Fox Snakes (Pantherophis gloydi) in response to habitatrestoration at Sterling State Park in Southeast Michigan. Report number 2006-17. Report to theMichigan Department of Natural Resources, Parks and Recreation Division, State Park StewardshipProgram, Lansing, MI. 31 pp + appendices.

Copyright 2006 MSU Board of Trustees

Monitoring of Eastern Fox Snakes at Sterling State Park 2005 Page - i

EXECUTIVE SUMMARY

The Eastern Fox Snake (Pantherophis gloydi) is astate threatened snake in Michigan that primarilyinhabits emergent wetlands along Great Lakesshorelines and associated nearshore areas alongsouthern Lake Huron, the Detroit River, Lake St. Clairand western Lake Erie. A population of Eastern FoxSnakes occurs in Sterling State Park in Monroe,Michigan. Since 2003, the Michigan Department ofNatural Resources’ (MDNR) State Park StewardshipProgram has been actively restoring portions ofSterling State Park’s landscape to native lakeplainprairie and Great Lakes marsh. In coordination withthe State Park Stewardship Program, Michigan NaturalFeatures Inventory (MNFI) initiated a monitoring andradio-telemetry study of the Eastern Fox Snakepopulation at Sterling State Park in 2003 andcontinued the study in 2004 and 2005 to assess impactsof the habitat restoration efforts on the fox snakepopulation in the Park. The goal of this monitoringprogram is to detect a biologically significant changein the Eastern Fox Snake population in areas targetedfor habitat restoration in the park.

Similar to work conducted in 2003 and 2004,mark-recapture surveys and radio-telemetry wereconducted in 2005 to collect data on fox snakepresence, relative abundance, movement, and habitatuse to assess impacts on fox snake populations inmanagement units undergoing active restorationduring and after habitat management activities. Line-transect and time-constrained visual encounter surveyswere conducted in all nine management units withinSterling State Park from 7 August to 5 September2005. Additional visual encounter surveys wereconducted in five management units on 12 May and 14and 19 June. These resulted in about 91 total hours offield surveys for Eastern Fox Snakes in Sterling StatePark in 2005. Four Eastern Fox Snakes were radio-tracked on a weekly or bi-weekly basis from 5 April to18 September. Tissue samples (i.e., scale clippings)also were collected in 2005 for future genetic analysis.

Field surveys in 2005 resulted in a total of only sixEastern Fox Snake observations, of which only fivewere captured. The five captured snakes were all new,unmarked snakes. Five of the six fox snakeobservations were documented during additional visualencounter surveys in June, and one snake was foundincidentally in September while tracking atransmittered snake. No fox snakes were documentedduring line-transect and time-constrained surveys in2005. An additional new fox snake was found and

captured by park staff in June 2005. Fox snakes werefound in only three of the nine management units inthe Park, consisting of two snakes in the InterpretiveKiosk Unit and four snakes in the Corps CDF andFacilities units. The habitats in which the fox snakeswere found include old field, palustrine scrub-shrub,and upland scrub-shrub along the edge of a pavednature trail.

Similar to survey and radio-telemetry results in2003 and 2004, the Eastern Fox Snakes that werefound during surveys or were radio-tracked in 2005primarily utilized open upland and wetland habitatssuch as old field, palustrine emergent wetland, andpalustrine scrub-shrub habitats, and were all locatedprimarily along the dike or along the edge of thelagoons and generally near the water or emergentwetland’s edge (i.e., generally within 1-3 m but furtheraway in some cases). Snakes were often found in orunder open or thick grass, shrubs or dense emergentvegetation, on or along the side of paved trails, in orunder concrete slabs or rock riprap along the shore ofthe open water lagoons, underground in tree rootnetworks or burrows, or on the surface or undergroundalong the embankment of the dike. Again, cover wasvery important for the fox snakes in the study. Theradio-telemetry results from 2005 also indicate that foxsnakes may exhibit some site fidelity and return to thesame hibernation site from one winter to the next.Telemetry results from 2005 also suggest fox snakesmay emerge from their overwintering sites a little laterin the spring than other snakes, and may stay near theiroverwintering sites for some time after emergence. Foxsnakes also may enter their overwintering sites earlierthan expected (i.e., around or by mid-September).

Although survey results from 2003-2005 may notbe conclusive in determining potential impacts ofhabitat restoration efforts on the fox snake populationin Sterling State Park in terms of relative abundancebecause of small sample sizes, survey and radio-telemetry results to date suggest that fox snake use ofparticular management units within the park may havebeen impacted to some degree. A majority of the radio-telemetry locations and locations at which fox snakeswere found during surveys occurred in areas that hadundergone some habitat restoration but generally hadnot been dramatically altered. Prior to this study,Eastern Fox Snakes had been documented in thesemanagement units as well as other units in the Parkwhich have undergone substantial alterations due tohabitat restoration activities, such as the Campground

Monitoring of Eastern Fox Snakes at Sterling State Park 2005 Page - ii

Restoration Unit. Surveys and radio-telemetry from2003-2005 did not document any fox snakes in thismanagement unit, but Park staff and contractorsreported seeing at least one fox snake in this unitduring the study.

Finally, although study results from Sterling StatePark in 2003-2005 indicate that Eastern Fox Snakescan inhabit highly disturbed and actively managedsites, the long-term viability of this population remainsunknown. The fox snake population within the parkcontinues to face a number of threats including highlydegraded and limited habitat (at least currently);population isolation; road mortality; intentional andunintentional killing, harassing or disturbance bypeople; incidental take or impacts due to parkmanagement activities (e.g., mowing of large areasreduce or minimize areas with sufficient cover forshelter, foraging, dispersal, and safe passage orprotection from predators); and predation. Theongoing restoration efforts may create additionalhabitat for fox snakes in the future, but also can pose

threats to the park’s fox snake population in the shortterm. Efforts to minimize threats to the fox snakepopulation within Sterling State Park should continue.Since fox snakes have been found primarily in theHunt Club, Interpretive Kiosk and Facilities unitsduring this study, consideration of managementactivities and ways to minimize potential adverseimpacts on Eastern Fox Snakes is especially warrantedin these units. Continued monitoring of Eastern FoxSnakes at Sterling State Park also should continue. Astudy funded by the Michigan DNR’s Wildlife Divisionwas initiated in 2006 to continue the fox snakemonitoring and radio-telemetry study at Sterling StatePark. This study has been conducted in conjunctionwith a similar study of Eastern Fox Snakes at TheNature Conservancy’s Erie Marsh Preserve, locatedabout 10 miles south of Sterling State Park. Sharingand comparing results among the two study sites willprovide additional insight into Eastern Fox Snakeecology and response to habitat management activities.

Monitoring of Eastern Fox Snakes at Sterling State Park 2005 Page - i

Table of Contents

EXECUTIVE SUMMARY ............................................................................................................................. i

INTRODUCTION .......................................................................................................................................... 1

STUDY AREA ................................................................................................................................................. 2

METHODS ...................................................................................................................................................... 4 Visual Encounter Surveys ........................................................................................................................... 4 Snake Observations ..................................................................................................................................... 6 Radio-telemetry ........................................................................................................................................... 7

RESULTS ........................................................................................................................................................ 9 Surveys ....................................................................................................................................................... 9 Radio-telemetry ......................................................................................................................................... 12

DISCUSSION ................................................................................................................................................ 25

FUTURE WORK .......................................................................................................................................... 29

REFERENCES ............................................................................................................................................. 30

ACKNOWLEDGEMENTS ......................................................................................................................... 31

APPENDICES ............................................................................................................................................. A-1

List of Tables

Table 1. Summary of visual encounter surveys conducted by Michigan Natural Features Inventory for Eastern FoxSnakes at Sterling State Park in Monroe County, Michigan in 2005. ......................................................................... 7

Table 6. Summary of radio-telemetry locations for Fox Snake F79705 in Sterling State Park in 2005. ......................... 20


Table 8. Summary of results of Eastern Fox Snake surveys conducted by MNFI from 2003-2005 in Sterling State Parkin Monroe County, Michigan. .................................................................................................................................. 26

Table 2. Summary of Eastern Fox Snake observations during visual encounter surveys conducted by Michigan NaturalFeatures Inventory in Sterling State Park in Monroe County, Michigan in 2005. .................................................... 10

Table 3. Summary of Eastern Fox Snakes and other snakes observed during visual encounter surveys in Sterling StatePark in Monroe County, Michigan in 2005. ............................................................................................................. 13

Table 4. Summary of radio-telemetry locations and habitats for Fox Snake J54904 in Sterling State Park in 2005. ..... 16


Monitoring of Eastern Fox Snakes at Sterling State Park 2005 Page - ii

Figure 1. Map showing general location of Sterling State Park in Monroe County, Michigan, as indicated by the redstar. ............................................................................................................................................................................. 3

Figure 2. Map of habitat management units in Sterling State Park, Monroe County, Michigan. ...................................... 5

Figure 4. Map of radio-telemetry locations for Fox Snakes J54904 (as indicated by the red dots), F29305 (purple dots),F79705 (yellow dots), and F12405 (blue dots) in Sterling State Park in 2005. ........................................................ 15

Figure 5. Map of radio-telemetry locations for Fox Snake J54904 in Sterling State Park in 2005 (as indicated by the reddots) and some of the radio-telemetry locations from 2004 (green dots). ................................................................ 17

Figure 6. Map of radio-telemetry locations for Fox Snake F29305 in Sterling State Park in 2005, as indicated by thepurple dots. ............................................................................................................................................................... 19

Figure 7. Map of radio-telemetry locations for Fox Snake F79705 in Sterling State Park in 2005, as indicated by theyellow dots. .............................................................................................................................................................. 21

Figure 8. Map of radio-telemetry locations for Fox Snake F12405 in Sterling State Park in 2005, as indicated by theblue dots. .................................................................................................................................................................. 23

Figure 9. Map of all Eastern Fox Snake locations based on visual encounter surveys (as indicated by the triangles) andradio-telelmetry (as indicated by the circles or dots) in Sterling State Park in Monroe County, Michigan from 2003-2005. ......................................................................................................................................................................... 24

Figure 3. Map of locations of Eastern Fox Snake observations during visual encounter surveys conducted by MichiganNatural Features Inventory at Sterling State Park in Monroe County, Michigan in 2005, as indicated by the red dots.Eastern Fox Snake observations documented during surveys in 2003, as indicated by the green triangles, and 2004,as indicated by the yellow triangles, also are shown on this map. ............................................................................ 11

List of Figures

List of Appendices

Appendix I. Maps of the locations of the line transects for the visual encounter surveys conducted by Michigan Natural Features Inventory in all nine management units within Sterling State Park in Monroe County, Michigan. ................................................................................................................................. A-3

Appendix II. 2005 Eastern Fox Snake Survey and Radio-Telemetry Data Form ....................................................... A-15

Appendix III. Michigan Natural Features Inventory (MNFI) Special Animal Survey Form ...................................... A-17

Monitoring of Eastern Fox Snakes at Sterling State Park 2005 Page-1

INTRODUCTION

The Eastern Fox Snake (Pantherophis gloydi) is afairly large (36-67 in / 91-168 cm), boldly patternedsnake that primarily inhabits emergent wetlands andadjacent uplands along Great Lakes shorelines andassociated large rivers and impoundments. The knownrange of this species is restricted to the shoreline andnearshore areas along southern Lake Huron fromSaginaw Bay in Michigan and Georgian Bay inOntario south to the Detroit River and Lake St. Clairand along northern and western Lake Erie fromNorfolk County in Ontario to Wayne and Monroecounties in Michigan and Erie County in Ohio(Harding 1997). The Eastern Fox Snake is primarilyassociated with open wetlands dominated byherbaceous vegetation but also will utilize drierhabitats such as vegetated dunes and beaches and openwoodlands (Harding 1997). The species also appearsto be able to utilize areas that have experienced somelevel of human disturbance including farm fields,pastures, woodlots, vacant urban lots, rock riprap,ditches, dikes, and residential homes (Harding 1997).

Little is known about the life history and ecologyof the Eastern Fox Snake; much of it is presumed to besimilar to that of the Western Fox Snake (Pantherophisvulpina) and other snakes in its genus (Evers 1994).Eastern Fox Snakes typically are active from mid-Aprilto October with peak activity in May and June (Evers1994, Harding 1997). Eastern Fox Snakes are usuallyfound near water and can swim long distances in openoffshore waters and between islands (Harding 1997).They feed primarily on small mammals, particularlymeadow voles (Microtus pennsylvanicus) and deermice (Peromyscus maniculatus), but also will eat birdeggs and nestlings, earthworms, insects, and frogs(Harding 1997). Eastern Fox Snakes probably breedannually, with breeding occurring in June and earlyJuly (Ernst and Barbour 1989, Harding 1997). Eggsare usually laid in late June or July in soil, woodydebris, decaying vegetation, or animal burrows (Ernstand Barbour 1989, Harding 1997). Hatching occursfrom mid-August to early October (Harding 1997).Eastern Fox Snakes hibernate in abandoned smallmammal burrows, muskrat lodges, or other suitableshelters (Ernst and Barbour 1989, Harding 1997).

The Eastern Fox Snake has declined in many areaswhere it was once abundant but can be locallycommon in areas where extensive habitat is stillavailable (Harding 1997). This species has beenreported from only approximately 40 sites inMichigan, and only about half of those sites have hadfox snakes reported within the last 10 years (Michigan

Natural Features Inventory 2006). The primary threatsto this species are habitat loss and degradation, humanpersecution, and collection for the commercial pettrade (Evers 1994, Harding 1997). Much of the foxsnake’s habitat has been ditched or drained foragricultural, residential, recreational, or industrialdevelopment (Lee 2000). The remaining suitablehabitats continue to be threatened by the same factorsas well as pollution and other forms of habitatdegradation such as the spread of invasive plantspecies (Lee 2000). Eastern Fox Snakes also arethreatened by increased road traffic and road densityassociated with development (Lee 2000). Additionally,Eastern Fox Snakes are often mistaken for venomoussnakes such as the Eastern Massasauga (Sistruruscatenatus catenatus) and Copperhead (Agkistrodoncontortrix) (which does not occur naturally in the wildin Michigan), and are often killed. As a result of itsdecline and ongoing threats to its persistence, theEastern Fox Snake has been listed and given protectionas a state threatened species in Michigan.

A population of Eastern Fox Snakes is known fromSterling State Park in Monroe County in southeastMichigan. In 2003, the Michigan Department ofNatural Resources’ (MDNR) State Park StewardshipProgram initiated an extensive ecological restorationeffort at Sterling State Park to restore a large portion ofthe Park’s landscape to native lakeplain prairie andGreat Lakes marsh. Lakeplain prairie and Great Lakesmarsh are rare and unique natural communities thatprovide suitable habitat for a number of rare plant andanimal species including the Eastern Fox Snake. Thesenatural communities or habitats were once commonalong the Great Lakes shoreline in southeast Michiganprior to European settlement but have been greatlyreduced in acreage and extensively altered due toagricultural, industrial, residential and recreationaldevelopment (Albert and Kost 1998, Albert 2001).Disruption of natural ecosystem processes, such asaltered hydrology and fire suppression, and invasion byexotic plants such as common reed (Phragmitesaustralis), purple loosestrife (Lythrum salicaria), andreed canary grass (Phalaris arundinacea) also havecontributed to the loss and degradation of these naturalcommunities (Albert and Kost 1998, Albert 2001).Lakeplain prairie and Great Lakes marsh habitats stilloccur in Sterling State Park but only in small,degraded remnants due to development andmanagement for recreational use, hydrologicalmanipulations, and the spread of invasive plants.Restoration efforts at Sterling State Park have been


ongoing since 2003. These efforts have includedspraying invasive plants with herbicides, prescribedburning, debris removal, extensive site preparation,mowing, seed collection, and planting native prairievegetation.

In 2003, in cooperation with the State ParkStewardship Program, the Michigan Natural FeaturesInventory (MNFI) initiated a monitoring and radio-telemetry program for the Eastern Fox Snake inconjunction with the habitat restoration efforts atSterling State Park. Eastern Fox Snakes had beenfound in many of the areas targeted for habitatrestoration in the Park. The goal of this monitoringprogram is to detect a biologically significant changein the Eastern Fox Snake population in areas targetedfor habitat management treatments in the Park. Thespecific objectives of this project are to (1) survey anddocument presence/absence, and estimate absoluteand/or relative abundance of Eastern Fox Snakes in allmanagement units within the Park, particularly thoseundergoing active management; (2) collect baselinepopulation data for statistical comparison with datafrom subsequent years; (3) collect tissue and/or bloodsamples for future genetic analysis of the Park’sEastern Fox Snake population; (4) determinemovement patterns and investigate ecology particularlytiming of emergence and hibernation of Eastern FoxSnakes within the Park; and (5) produce baselinegeographically referenced habitat and snakedistribution data for comparison with post-management data. This study will provide baselineinformation with which to assess the effects of thehabitat restoration efforts on the resident Eastern FoxSnake population in Sterling State Park (e.g., is

population increasing, decreasing or remainingconstant) and provide data for future adaptivemanagement. This study also will enhance ourknowledge of Eastern Fox Snake life history andecology and potential impacts of land managementactivities on this species.

Surveys for Eastern Fox Snakes were conducted atSterling State Park in 2003 immediately prior to andduring initiation of habitat restoration efforts andcontinued in 2004 and 2005 after extensive habitatrestoration activities had been conducted in the Park.Radio-tracking of a small sample of Eastern FoxSnakes and collection of blood and/or tissue samplesalso were conducted during 2003 - 2005 in addition tomonitoring surveys. Results from the fox snakesurveys and radio-telemetry conducted in 2003 and2004 suggested that fox snake numbers within SterlingState Park may not have been dramatically impactedby initial habitat restoration activities although foxsnake use of particular management units may havebeen impacted to some degree (Lee 2004). However,results from 2003 and 2004 were inconclusive due tolimited data (i.e., small sample sizes, short time frameand little pre-treatment data) (Lee 2004). Additionalsurveys and radio-telemetry and a long-termmonitoring effort are needed to further assess theshort- and long-term impacts of habitat restorationefforts on the Eastern Fox Snake population withinSterling State Park. Limited surveys and radio-trackingcontinued in 2005 with funding from the State ParkStewardship Program. This report summarizes projectactivities and results from 2005 and also providescomparisons with study results from 2003 and 2004.

Sterling State Park is a 405-ha (1,000-acre) parklocated along the Lake Erie shoreline in MonroeCounty, Michigan in the southeast corner of the stateapproximately 61 km (38 mi) south of Detroit and 39km (24 mi) north of Toledo, Ohio (Figure 1). Based onregional landscape ecosystem classifications ofMichigan (Albert 1995), Sterling State Park is locatedwithin the Maumee Lake Plain of the Washtenaw sub-section. This region is a flat, clay lake plain dissectedby broad glacial drainageways of sandy soil (Albert1995). Historically (circa 1800), Sterling State Parkwas comprised primarily of Great Lakes marsh with aband of wet or lakeplain prairie and a small area ofmesic southern forest in the northwest portions of thePark. Additional information on the historical andcurrent land cover in Sterling State Park can be foundin Olson (2002) and Lee (2004).

Alteration of the historical land cover withinSterling State Park has been extensive (Olson 2002).Much of the marsh habitat was initially drained foragricultural use and then was dredged to createchannels and a diked area that historically controlledwater levels for transportation access and later huntingaccess. Extensive dredging occurred in the 1950’s and1960’s to create open water lagoons and upland areasin the park for recreational use (Olson 2002). Aconfined disposal facility (CDF) was constructed bythe U.S. Army Corps of Engineers in the early 1980’sby dredging portions of the marsh in the northeastcorner of the park. Soil from the construction of theCDF was placed throughout the park, raising theelevation of portions of the park and creating manyspoil piles, berms and a series of small “islands” in the

STUDY AREA


Figure 1. Map showing general location of Sterling State Park in Monroe County, Michigan, as indicatedby the red star.


marsh immediately west of the CDF (Olson 2002). Theupland areas in the park also were once farmed (Olson2002).

Given these widespread alterations, the land coverwithin Sterling State Park has dramatically changed.The wetlands in Sterling State Park are currently a mixof open water lagoons, mud flats, floating aquatics andsmall remnants of Great Lakes marsh and lakeplainprairie. The upland areas are primarily open andcomprised of a mix of natural habitat and areasdeveloped or managed for recreational use. The inlandareas that once supported lakeplain prairie are nowprimarily old fields with various spoil piles, berms anddebris (Olson 2002). The mesic southern forest thatonce occupied the farthest inland portions of SterlingState Park is almost completely gone. The smallpatches or strips of forest that remain in the park occuralong a raised dike/paved trail and the edge orperimeter of open upland and wetland habitats. Sugarmaple (Acer saccharum), boxelder (Acer negundo),cottonwood (Populus deltoides), willows (Salix spp.),ash (Fraxinus spp.), and dogwood (Cornus spp.)commonly occur in the forested habitats. Invasivespecies such as purple loosestrife, common reed orPhragmites, and reed canary grass can be foundthroughout the park. Sterling State Park is heavily usedfor recreation and contains a number of developed ormanaged recreational facilities including roads, pavedparking lots, paved trails, interpretive area, mowedgrass, landscaped areas, boat launch, buildings,playground, beach and campground. Water levels areno longer controlled anywhere in the park, althoughdikes, ditches, culverts and rock riprap along thelagoons and portions of the Lake Erie shorelinecontinue to influence hydrology within the park.

Sterling State Park has been divided into ninemanagement units. These include the following:Headquarters (HQ), Bean Field (BF), CampgroundRestoration (C), Corps Volcano (V), Hunt Club (HC),

Interpretive Kiosk (IK), North Lagoons (NL), CorpsCDF (CDF) and Facilities (F) (Figure 2). Of these, thefollowing six units have been targeted for habitatrestoration efforts: Bean Field, Corps Volcano,Campground Restoration, North Lagoons, Hunt Cluband Interpretive Kiosk. The remaining threemanagement units, Headquarters, Facilities and CorpsCDF, have not been targeted for active restoration,although some patches of Phragmites along thelagoons on the west side of the Facilities Unit weresprayed in 2003. Brief descriptions and photographs ofhabitat types in each of the nine management units in2003 and 2004 prior to and after initiation of habitatrestoration activities are provided in Lee (2004).

Habitat conditions in 2005 were generally similarto conditions in 2004 in most management unitsexcept for a few units which are still undergoing activehabitat restoration. During the fox snake surveys in2004, most of the Campground Restoration Unitconsisted of bare dirt and lacked vegetative coverexcept for some old field and emergent marsh habitatsalong the northern, eastern and southern edges of theunit. In 2004, most of the Campground RestorationUnit was graded down to historical contours to restoreGreat Lakes marsh transitioning inland to lakeplainprairie. The Campground Restoration Unit was plantedin 2004 and 2005, and more vegetation was present inthe unit during surveys in 2005 but vegetative coverwas still fairly sparse in a large portion of the unit. Theamount of Phragmites has been significantly reducedin the North Lagoons, Campground Restoration, CorpsVolcano, Hunt Club, Interpretive Kiosk and Facilitiesunits compared to conditions in 2003. Spraying withherbicides and/or burning have continued though inportions of several units to continue to controlPhragmites. Herbicide spraying, burning, planting,and/or mowing also have continued in the InterpretiveKiosk Unit to restore lakeplain prairie to parts of theUnit.

METHODS

Visual Encounter SurveysSimilar to surveys conducted in 2003 and 2004,

surveys for the Eastern Fox Snake in 2005 wereconducted in all nine management units within SterlingState Park including the six units that have beentargeted for restoration (i.e., Bean Field, CorpsVolcano, Campground Restoration, North Lagoons,Hunt Club and Interpretive Kiosk) and the three unitsnot currently targeted for active restoration (i.e.,Headquarters, Facilities and Corps CDF). Due to thelack of access to the interior of the Corps CDF Unit,

surveys were conducted outside the fence along theperimeter of the unit. Surveys in the North LagoonsUnit were conducted only along the southern andeastern perimeters of the unit due to limited access(i.e., narrow strips of dense emergent vegetationseparated by deep water in the lagoons). Surveys in theFacilities Unit were concentrated along the westernand southern boundaries of the unit and generallyavoided areas that are highly developed or heavily usedfor recreation (e.g., campground, playground, parkinglot, etc.). Surveys in the Hunt Club Unit were


Figure 2. Map of habitat management units in Sterling State Park, Monroe County, Michigan.


conducted along the dike or paved trail and in areaswith habitat that were accessible along the edge of thelagoon.

Eastern Fox Snakes were surveyed in 2005 usingline-transect and time-constrained visual encountersurveys (VES) similar to those that had beenconducted in 2003 and 2004. For the line-transectVES, multiple transects of 150 m were systematicallyplaced and surveyed within each unit. Sampling effortin terms of the number of survey transects within eachunit was proportional to the size of the unit or theamount of suitable and accessible habitat within eachunit (i.e., ~1 transect per 1.5 ha) (Table 1). Surveytransects were geographically distributed throughouteach unit and in areas that represented the range ofhabitat types within each unit whenever possible. Thesurvey transects were established in 2003, and thelocation of each survey transect was recorded using ahand-held Global Positioning System (GPS) unit(Garmin 12XL) (Appendix I; for GPS locations, seeLee 2004). The same transects were located andsurveyed in 2004 and 2005. In a few managementunits, one or two transects or portions of transects hadto be moved slightly to nearby habitat due to thepresence of tall, dense vegetation. Transects werelocated and marked with plastic flagging and wireflagging stakes in early August 2005 for field surveys.

In 2005, line-transect visual encounter surveyswere conducted from 7 August to 5 September. A totalof four transect surveys were conducted in eachmanagement unit during this time period (Table 1).The surveyor and the order in which management unitswere surveyed were randomly assigned to minimizesurvey bias. Transect surveys consisted of one or twosurveyors slowly walking along a transect and visuallysearching for basking individuals as well as individualsunder cover on both sides of the transect. All transectsin each unit were surveyed during each visit.

Time-constrained visual encounter surveys alsowere conducted in each management unit in 2005during the same time period as the line-transectsurveys. A total of four time-constrained VES wereconducted in each management unit (Table 1). Time-constrained surveys were generally conductedimmediately after transect surveys within each unit.Time-constrained surveys consisted of one or twosurveyors meandering or slowly walking through areaswith suitable habitat within each unit and visuallysearching for basking individuals as well as individualsunder cover for a prescribed period of time per survey.Time-constrained survey durations ranged from 0.5 to1.7 person-hours (i.e., 30-100 minutes), and were

generally proportional to the size of the unit and theamount of available habitat within the unit (Table 1).The time-constrained survey durations or time limitsused during the surveys in 2005 were established in2004 and were slightly higher but comparable to timeconstraints utilized in 2003 (i.e., 20-90 minutes).

Additional visual encounter surveys for EasternFox Snakes were conducted in 2005 on 12 May and 14and 19 June in five of the nine management units(Table 1). The purpose of these surveys was to findadditional fox snakes for radio-telemetry, populationestimation and tissue sample collection. These surveysalso were conducted in the spring to investigate theeffectiveness of spring surveys compared to latesummer/early fall surveys. Surveys generally consistedof 1-2 surveyors walking through areas with suitablehabitat and visually searching for snakes above groundand under cover.

All visual encounter surveys were conductedbetween 8 am and 7 pm during appropriate weatherand survey conditions when the snakes were likely tobe active or visible. An Eastern Fox Snake monitoringfield form was developed and completed for eachsurvey visit (Appendix II). Information on surveydates, times, duration, weather conditions, transects,macrohabitat, microhabitat and snake observationswas recorded on these field forms.

Snake ObservationsAll Eastern Fox Snakes and other snakes and

herpetofauna observed during field surveys weredocumented. Similar data were recorded in 2005 as in2003 and 2004. The behavior, estimated length, andage class of each observed snake were recordedwhenever possible. The macro- and microhabitats inwhich each snake was found also were recorded. Thebehavioral, macrohabitat, and microhabitatclassifications used in this study have been used inother snake studies (Kingsbury 2001, Kingsbury et al.2001). Snake behavioral classifications includedbasking, resting, courting, mating, foraging, traveling,and unknown. Macrohabitat classifications were basedon National Wetland Inventory (NWI) classifications(Cowardin et al. 1979) and included palustrine forestedwetland (PFO), palustrine scrub-shrub wetland (PSS),palustrine, sedge-dominated emergent wetland (SDG),palustrine, cattail-dominated emergent wetland (CAT),upland forest (UFO), upland scrub-shrub (USS), andold field (OLD). Microhabitat classifications includedshrub, sedge, grass, rock, log, herb (herbaceous/notgrass), bare, island (small hummock in open water),detritus, and other. More specific macro- and


Area Line -Transect VES Time-Constrained VES Additional VES Management

Unit ha (ac) # Transects Dates Time (mins) Dates # Surveys Dates

Headquarters 7 (17)

2 8/7, 8/15, 8/26, 8/30

30 8/7, 8/15, 8/26, 8/30

0

Bean Field 32 (80)

16 8/7, 8/15, 8/25, 9/5

60 8/7, 8/15, 8/25, 9/5

0

Corps Volcano 35 (88)

20 8/7, 8/17, 8/26, 9/2

90 8/7, 8/17, 8/26, 9/2

0

Campground Restoration

44 (109)

14 8/11, 8/17, 8/26, 9/2

60 8/11, 8/17, 8/26, 9/2

1 6/19

Interpretive Kiosk

7 (16)

7 8/7, 8/18, 8/25, 8/30

50 8/7, 8/18, 8/25, 8/30

2 6/14, 6/19

Hunt Club* 92 (226)

11 8/11, 8/18, 8/25, 9/5

100 8/11, 8/18, 8/25, 9/5

1 5/12

North Lagoons* 35 (86)

3 8/11, 8/18, 8/26, 9/5

30 8/11, 8/18, 8/26, 9/5

0

Corps CDF* 39 (97)

4 8/7, 8/17, 8/26, 8/30

40 8/7, 8/17, 8/26, 8/30

1 6/19

Facilities* 122 (303)

14 8/7, 8/18, 8/21, 9/5

80 8/7, 8/18, 8/21, 9/5

1 6/19

Total 91 540 6

Table 1. Summary of visual encounter surveys conducted by Michigan Natural Features Inventory for Eastern FoxSnakes at Sterling State Park in Monroe County, Michigan in 2005.

*Denotes management units with significant portions that were inaccessible, developed, and/or did not contain suitablehabitat for Eastern Fox Snakes.

microhabitat information (e.g., natural communitytype, dominant plant species) was recorded whenpossible.

Locations of Eastern Fox Snakes were recordedusing a hand-held GPS unit. Observed fox snakes werecaptured, measured, weighed, and sexed, whenpossible. Total length, snout-vent length (SVL), andtail length were measured and recorded for allcaptured fox snakes. Total length was used to helpdetermine age class designations with adult snakesranging from about 90 – 170.5 cm (35-67 in), sub-adults or juveniles ranging from 32 – 89 cm (13- 35in) and newly hatched or young snakes ranging from26 – 31 cm (10-12 in) (Harding 1997). Adult and sub-adult or juvenile fox snakes were individually markedwith PIT (passive integrated transponder) tags in thefield or in the lab (i.e., for snakes that were alsoimplanted with transmitters). The PIT tags wereinjected subcutaneously dorsal to the vent (i.e., cloacalopening) using a 10-gauge sterile syringe pre-loadedwith the microchip. A tissue sample (i.e., scaleclipping) also was collected from adult and sub-adultor juvenile fox snakes in the field or in the lab, whenpossible, and stored appropriately for future geneticanalysis. A scale clipping was obtained from a ventralscale anterior to the vent using sterilized surgical

scissors. In 2003 and 2004, a blood sample consistingof approximately 0.1-0.2 ml of blood was collectedfrom the caudal (tail) vein of each captured fox snakeusing a sterile needle and syringe. However, bloodsamples were not collected in 2005. Photographs weretaken of each captured fox snake for documentation.After all processing and data collection werecompleted, snakes were released at their respectivecapture sites. Michigan Natural Features Inventory’sspecial animal survey forms were completed forsurveys with fox snake observations (Appendix III).

Radio-telemetryThree Eastern Fox Snakes were radio-tracked to

their apparent hibernation sites in the fall of 2004, butonly one of these snakes was radio-tracked in 2005.These snakes were first captured, implanted withradio-transmitters and radio-tracked during the springand summer of 2004. Two of the snakes, an adult maleand a sub-adult (sex unknown, possibly male), werecaptured during visual encounter surveys on 10 and 17May 2004 and were radio-tracked through the spring,summer and early fall until 23 September 2004. One ofthese snakes, the adult male, was radio-tracked to alocation underneath a large cottonwood tree on the eastside of the dike or paved trail in the southeast corner of


membrane). A radio-transmitter was then inserted intothe body cavity. Radio-transmitters weighing 9 grams(1 cm wide x 3 cm long cylinder, 20 cm whip antenna,18-month life span, Holohil Systems Ltd.) wereimplanted in the three adult female snakes. A smallertransmitter weighing 5 grams (0.95 cm wide x 2 cmlong cylinder, 12-month life span, Holohil SystemsLtd.) was used in the adult male snake because of itsbody mass or weight (i.e., only about 200 g). Althoughuse of the 9-g transmitter in this snake would havebeen under the recommended limit of 5% transmittermass to snake body mass ratio (Reinert 1992, Hardyand Greene 1999), the 5-g transmitter was used to beconservative. The antenna was placed subcutaneouslyalong the body of the snake, anterior to the initialincision through a second, small incision. The primaryincision was closed with PDS absorbable suture andsurgical skin glue. The second incision was simplyglued closed with skin glue.

After recovery from the anesthesia, the snakeswere moved to a housing area. The housing area waskept at 80-82oF, which is the temperature many snakesseek in the field during summer months based onprevious studies. When the temperature fell below thislevel, a heat source (light bulb or heating pad) wasplaced near or under the terrarium in order to establisha thermal gradient. This allowed the snakes tobehaviorally thermoregulate by moving towards oraway from the heat source. The photo period of theroom was 14:8 day:night. Each snake was heldindividually in a clean terrarium, away from otheranimals that might act as a source of pathogens. Thesnakes were inspected several times a day. Handlingof the snakes during the recovery period was kept to aminimum. Water was provided, but food was not. Thesnakes were held for observation for 3-6 days (7 daysmaximum) after the surgery and then released at theirrespective capture sites in the park.

Once released, the snakes were radio-tracked on aweekly or bi-weekly basis throughout the field seasonfrom 22 June to 18 September 2005. The snakes werelocated during different times of the day between 9 amand 8:30 pm. The position of each location wasrecorded using a hand-held GPS unit and plotted on anaerial photo of the park using ArcView GIS (ESRIInc.). At each location, the macro- and microhabitats inwhich the snake was found, the behavior of the snake,and weather conditions were recorded. The pulseinterval of the radio-transmitter also was recorded andwas used to estimate the body temperature of thesnake. A visual confirmation of the radio-tracked snakewas obtained when possible. The snakes were radio-tracked to their hibernation sites in the fall.

the Hunt Club Unit in the fall of 2004, and the snakeapparently overwintered at this location. The snake (ortransmitter) was tracked to this location several timesin the spring and early summer of 2005, and the snakewas presumed to be dead because the transmittersignal never moved from this location in 2005. Thesub-adult snake fox snake that was tracked in 2004was relocated in April 2005 and was radio-tracked on aweekly or bi-weekly basis from 5–29 April and 2 Julyto 18 September 2005. The third snake, an adult male,was captured during time-constrained VES on 24August 2004. It was implanted with a transmitter on30 August and released back into the field at itscapture site on 2 September 2004. The snake wasradio-tracked several times until 23 September 2004but had not moved from its initial capture site since itsrelease. In April 2005, the transmitter was found on theground at or near its initial capture site.

Four new fox snakes were found and capturedduring additional visual encounter surveys conductedon 14 and 19 June 2005 for the radio-telemetry study.These snakes were comprised of three adult femalesand one adult male (based on total lengths). One adultfemale and the adult male were found on 14 June inthe Interpretive Kiosk Unit south of the parking lot atthe north end of the unit (Figure 3). The other twoadult females were found together in or around theentrance of a burrow located on the side of a pavedtrail that runs along the fence surrounding the CorpsCDF Unit in the northeast corner of the Facilities Unit(Figure 3) on 19 June. Both snakes appeared to beready to shed their skins.

The four snakes were transported to the laboratoryof Dr. Bruce Kingsbury, Biology Department Chair atIndiana-Purdue University at Ft. Wayne, whosurgically implanted radio-transmitters in the snakesusing the following protocol. Each snake wasanesthetized by placing it into a sealed chamber with asmall container of isoflurane which vaporizes andpermeates the chamber. The snake was measured,weighed, and sexed once it was anesthetized. Also,while the snake was anesthetized, the snake was PIT-tagged, and a scale clipping and/or blood sample werecollected if necessary. Transmitters were implantedusing a technique modified from Reinert and Cundall(1982). A small lateral incision was made on theventral side of the body cavity approximately two-thirds of the way down the body. The incision wasplaced slightly above the surface that slides across theground when the snake moves. Rather than cutthrough the body wall, the body wall was easilyseparated with little or no blunt dissection, and anincision was made in the peritoneum (body cavity


RESULTS

SurveysIn 2005, MNFI conducted about 91 hours of field

surveys for the Eastern Fox Snake in Sterling StatePark, with approximately 81 hours of line-transect andtime-constrained visual encounter surveys (61 hoursfor line-transect, 20 for time-constrained) and about 10hours of additional visual encounter surveys in Mayand June. Given that some surveys were conducted bymultiple individuals, a total of about 171 person-hoursof surveys were conducted, with about 121 person-hours of line-transect surveys, about 36 person-hoursof time-constrained surveys, and about 14 person-hours of additional visual encounter surveys in Mayand June. Surveys were conducted by two primaryindividuals working with four different volunteers.

Overall, field surveys in 2005 resulted in a total ofonly six eastern fox snake observations, of which onlyfive were captured (Table 2). Five of the six fox snakeobservations were documented during additional visualencounter surveys conducted on 14 and 19 June. Thesixth fox snake observation was made incidentallywhile tracking a transmittered snake in September. Nofox snakes were observed during line-transect andtime-constrained surveys in 2005. The five capturedsnakes were all new snakes. One snake escapedcapture when it was observed but may have been oneof the snakes that was captured later that day at thesame location. Two of the fox snakes were found in theInterpretive Kiosk Unit, and the other four fox snakeobservations were located along or near the fencesurrounding the Corps CDF Unit in the northeastportion of the Facilities Unit. Figure 3 provides anaerial photograph of Sterling State Park with thelocations of the fox snakes observed in 2005 as well asfox snakes found during surveys in 2003 and 2004 forcomparison.

Of the five fox snakes that were captured in 2005,four were considered adults with total lengths rangingfrom about 96.5–109.5 cm (38-43 in) and weightsranging from 205 – 486 g (Table 2). The remaining foxsnake was considered to be a young-of-the-year with atotal length of 32.5 cm (12.8 in) and a weight of 10 g.The snake that escaped capture appeared to be an adultbased on its body size. Three of the adult snakes wereprobed in the lab and were identified as females, andthe other adult snake was a small male. The sex of theyoung snake is unknown because this is difficult todetermine visually when the snake is so small and itwas not probed in the field because of its size. Tissuesamples (i.e., scale clippings) were collected from allfour adult snakes but not from the young snake

because of its small size. All four adult snakes weremarked with a PIT tag and white liquid paper on thetips of their tails. All four adult snakes also wereimplanted with radio-transmitters and added to theradio-telemetry study. The young snake was not PIT-tagged because of its size and was only marked withwhite liquid paper on the tip of its tail.

Additional fox snake observations were reportedby Sterling State Park and State Park StewardshipProgram staff. A sub-adult fox snake was actuallypicked up by Sterling State Park staff on 16 June 2005.The snake was observed basking next to the paved trailalong the fence surrounding the Corps CDF Unit in thenortheast corner of the Facilities Unit at the samelocation at which MNFI staff found two fox snakes on19 June 2005. The fox snake was given to MNFI staffand was measured, weighed, PIT-tagged and releasedat its capture site on 19 June.

The fox snakes observed during field surveys in2005 were found in several different habitats andmicrohabitats (Table 2). One of the fox snakes found atthe northern end of the Interpretive Kiosk Unit wasfound resting in herbaceous vegetation in a narrowband of palustrine scrub-shrub habitat dominated bywillow along the lagoon about two meters from thewater’s edge. The other snake found in the InterpretiveKiosk Unit was basking in grass in open old fieldhabitat adjacent to the scrub-shrub habitat in which theprevious snake was found. The three fox snakesobserved along the fence surrounding the Corps CDFUnit were found basking or resting in or near theentrance of a burrow along the side of a paved trailthat runs along the fence surrounding the Corps CDFUnit. The habitat in the Corps CDF Unit immediatelyadjacent to the burrow was upland scrub-shrub withtall, dense shrubs but nearby habitats in the Corps CDFUnit and along the trail in the Facilities Unit weremore open and consisted of old field, emergent marshand palustrine scrub-shrub wetlands. Interestingly, thesnake that was picked up by the Sterling State Parkstaff also was found basking in or near the sameburrow along the paved trail under the Corps CDFfence. The last fox snake was observed in grassy oldfield habitat near the fence surrounding the Corps CDFUnit between the fence and the paved trail.

Fox snake detection frequencies or detection ratesfor the surveys can be calculated for the park as awhole based on the number of fox snakes observed andsurvey effort in terms of survey hours and/or person-hours. Only five fox snake observations weredocumented in about 91 hours for all visual encounter


Date

Man

agem

en

t U

nit

Su

rvey T

yp

e1

(LT

S, T

CS

, A

VS

)

Cap

ture (

C)/

Recap

ture (

R)

PIT

tag I

D #

Age c

lass

2

(A, S

/J, Y

)

TL

/SV

L3

(cm

)

Weig

ht

(g)

Sex

4

(M, F

, U

)L

ati

tud

eL

on

git

ud

eM

acroh

ab

itat5

Mic

roh

ab

itat

Beh

avio

r

Rad

io-

tran

smit

tered

?

06/1

4/20

05In

terp

retiv

e K

iosk

AV

SC

087

353

293

A10

9.5/

9540

1F

N 4

1 55

.013

'W 8

3 20

.373

'PSS/

scru

b-

will

owhe

rbac

eous

rest

ing

Y06

/14/

2005

Inte

rpre

tive

Kio

skA

VS

C08

7 29

3 53

9A

97.7

5/81

.520

5M

N 4

1 55

.018

'W 8

3 20

.374

'OL

D

gras

sba

skin

gY

06/1

6/20

05C

orps

CD

FSt

erlin

g SP

sta

ffC

087

310

521

S82

.5/7

117

5M

N 4

1 54

.819

'W 8

3 19

.990

'pav

ed w

alk

bare

bask

ing

N

06/1

9/20

05C

orps

CD

FA

VS

Esc

aped

ca

ptur

e; m

ay

be s

nake

087

32

0 12

4 ca

ught

la

ter

that

day

no p

it ta

gA

Unk

Unk

UN

41

54.8

19'W

83

19.9

90'p

aved

wal

kbu

rrow

rest

ing

N06

/19/

2005

Cor

ps C

DF

AV

SC

087

305

797

A10

9/96

.548

6F

N 4

1 54

.819

'W 8

3 19

.990

'pav

ed w

alk

bare

bask

ing

Y06

/19/

2005

Cor

ps C

DF

AV

SC

087

320

124

A96

.5/8

5.5

300

FN

41

54.8

19'W

83

19.9

90'p

aved

wal

kba

reba

skin

gY

09/0

2/20

05C

orps

CD

F/Fa

cilit

ies

AV

SC

no p

it ta

gY

32.5

/28

10U

N 4

1 54

.796

'W 8

3 20

.068

'OL

D

gras

sun

know

nN

1 Surv

ey ty

pe: L

TS

= lin

e-tr

anse

ct v

isua

l enc

ount

er s

urve

y, T

CS

= tim

e-co

nstr

aine

d vi

sual

enc

ount

er s

urve

y, a

nd A

VS

= ad

ditio

nal v

isua

l enc

ount

er s

urve

y2 A

ge c

lass

: A =

adu

lt (~

90-1

70 c

m),

S/J

= s

ub-a

dult/

juve

nile

(~3

2-89

cm

), Y

= y

oung

(~2

6-31

cm

)3 T

L/S

VL

: TL

= to

tal l

engt

h, S

VL

= s

nout

-ven

t len

gth

4 Sex:

M =

mal

e, F

= f

emal

e, U

=un

know

n5 M

acro

habi

tat:

OL

D =

old

fie

ld, P

EM

= p

alus

trin

e em

erge

nt w

etla

nd, P

SS =

pal

ustr

ine

scru

b-sh

rub,

PFO

= p

alus

trin

e fo

rest

, PO

W =

pal

ustr

ine

open

wat

er,

USS

= u

plan

d sc

rub-

shru

b, U

FO =

upl

and

fore

st.

Tabl

e 2.

Sum

mar

y of

Eas

tern

Fox

Sna

ke o

bser

vatio

ns d

urin

g vi

sual

enco

unte

r sur

veys

cond

ucte

d by

Mic

higa

n N

atur

al F

eatu

res I

nven

tory

inSt

erlin

g St

ate

Park

in M

onro

e C

ount

y, M

ichi

gan

in 2

005.


Figure 3. Map of locations of Eastern Fox Snake observations during visual encounter surveys conducted by MichiganNatural Features Inventory at Sterling State Park in Monroe County, Michigan in 2005, as indicated by the red dots.Eastern Fox Snake observations documented during surveys in 2003, as indicated by the green triangles, and 2004, asindicated by the yellow triangles, also are shown on this map.


surveys combined in 2005, resulting in a detectionfrequency of about 0.05 fox snake observations/surveyhour. For total person hours, five fox snakeobservations were documented in about 171 person-hours, resulting in a detection frequency of 0.03 foxsnake observations/person-hour. However, detectionfrequencies based solely on additional visual encountersurveys conducted in May and June were much higher,with about 0.5 fox snake observations/survey hour (5fox snake observations in a total of about 10 surveyhours) and about 0.4 fox snake observations/person-hour (5 observations in about 14 person-hours). Onlyfive fox snake observations instead of six were used inthe detection frequency calculations because only fivewere observed during actual visual encounter surveysand one snake was observed incidentally during radio-telemetry.

In addition to Eastern Fox Snakes, a total of 15observations of other snake species were documentedduring field surveys in 2005. These included 11Eastern Garter Snake (Thamnophis sirtalis sirtalis)observations, 2 Butler’s Garter Snake (Thamnophisbutleri) observations, 1 Brown Snake (Storeria dekayi)observation, and 1 unidentified snake observation(Table 3). Of the total number of snakes observed, 6observations were made during the line-transect andtime-constrained visual encounter surveys, and 9observations were made during additional visualencounter surveys. These observations weredocumented in only four management units whichincluded the Corps CDF, Facilities, Hunt Club andInterpretive Kiosk units. It is important to note thatthese observations may not all represent separateindividuals since repeated surveys of the same areaswere conducted and observed animals were notmarked.

Other amphibian and reptile species also wereobserved during field surveys in 2005. These includedat least 12 Northern Leopard Frog (Rana pipiens)observations, 1 Bullfrog (Rana catesbeiana)observation, 2 Green Frog (Rana clamitans melanota)observations, 39 Painted Turtle (Chrysemys picta)observations, 5 Common Map Turtle (Graptemysgeographica) observations, and 1 Common SnappingTurtle (Chelydra serpentina serpentina) observation.Most of the turtles were observed basking on logs inthe water in the Hunt Club Unit.

Radio-telemetryA total of four Eastern Fox Snakes were radio-

tracked in 2005 on a weekly or bi-weekly basis from 5April to 18 September (Figure 4). Of these, one was

initially captured and radio-tracked in 2004, and therest were new snakes that were captured and added tothe study in June 2005. An additional fox snake wascaptured and implanted with a radio-transmitter in2005, but we were never able to obtain a transmittersignal for this snake after it was released. This snakewas an adult male that was captured on 14 June 2005in the Interpretive Kiosk Unit. The snake wasimplanted with a 5-g transmitter instead of a 9-gtransmitter which is the type of transmitter that wasimplanted in the other three snakes. The 5-gtransmitter may have been faulty since otherresearchers have reported having problems with thesetransmitters.

The fox snake that was radio-tracked in 2004 (PITtag#: 052 563 549, hereafter referred to as J54904)was initially captured in the Interpretive Kiosk Unitduring additional visual encounter surveys on 17 May2004. The snake was a juvenile or sub-adult (sexunknown, possibly male) that weighed 99 g and wasapproximately 77 cm (30 in) in total length (SVL = 64cm/25 in, tail length = 13 cm/5 in) at the time of itscapture. Because this snake was a juvenile, a 5-gradio-transmitter instead of a 9-g transmitter wassurgically implanted into the snake. J54904 was radio-tracked to 11 locations from 17 June to 23 September2004. During the radio-tracking period in 2004,J54904 was mostly located in the Interpretive KioskUnit in the vicinity of its initial capture site but wasalso located a few times on the other side of the lagoonin the Facilities Unit near the foot bridge (Figure 5).The snake hibernated underground along the raiseddike or paved trail just north of the pavilion in theInterpretive Kiosk Unit about 2 m from the water’sedge. The snake was radio-tracked to this location thefollowing spring during three visits on 4, 17 and 29April 2005. The snake was presumed to be deadbecause it had not moved from its overwintering site asof late April. However, the snake was tracked to adifferent location and was captured, weighed andmeasured on 2 July 2005. The snake appeared to behealthy. It weighed 235 g and was 96 cm (38 in) intotal length (SVL – 82 cm/32 in, tail length = 14 cm/5.5 in), indicating a substantial increase in size fromthe previous year. The tail length and proportion of taillength to SVL or total length suggest that this snake islikely a male. During the radio-tracking period in2005, J54904 was located exclusively in theInterpretive Kiosk Unit, moving north and south alongthe dike in this unit (Table 4 and Figure 5). On 2September, the snake was located near itsoverwintering location from 2004. However, we wereunable to get a signal and were not able to locate the


Table 3. Summary of Eastern Fox Snakes and other snakes observed during visual encounter surveys in SterlingState Park in Monroe County, Michigan in 2005.

snake on 8 and 18 September to determine itsoverwintering location for 2005. The snake’stransmitter may have failed due to a dead battery.

J54904 was found primarily in open habitat typesin 2005 as in 2004 (Table 4). J54904 was foundprimarily in herbaceous vegetation in old field habitatsand also under rock in palustrine scrub-shrub habitats.Of the 10 active locations to which this snake wastracked in 2005, 7 were in old field habitats (70% oflocations) and 3 were in palustrine scrub-shrub (30%).The snake was observed only twice during the radio-tracking period and was primarily either in or undervegetation or under rocks the rest of the time. Themaximum distance between the two farthestdocumented locations for J54904 was approximately470 m (0.3 mi) in 2005 and in 2004. This distance maybe an underestimate of the maximum distance thissnake can travel within its home range since this snakewas only tracked on a weekly or bi-weekly basis andwas not tracked or monitored continuously during theactive season. It also was not tracked in May and Junewhen fox snakes are believed to be most active.

The adult female that was initially captured in theInterpretive Kiosk Unit during additional visualencounter surveys on 14 June 2005 (PIT tag #: 087 353

293, hereafter referred to as F29305) spent most of thesummer along the shore of the northern lagoon in theFacilities Unit just south of the main park road andboat lauch area (Table 5 and Figure 6). After its releaseon 22 June 2005, the snake remained in theInterpretive Kiosk Unit until mid-July when it slowlymoved north to the Facilities Unit where it stayed frommid-July through early September. The snake thenreturned to the Interpretive Kiosk Unit in earlySeptember and overwintered about 150 m from itsinitial capture site.

Most of F29305’s locations during the radio-tracking period in 2005 were underground or in rockor rock riprap along the shore of the lagoons in theFacilities Unit, with 10 of its 13 locations (77%) in thishabitat type (Table 5). A few of the locations were inscrub-shrub habitat in or under dense shrubs. We wereonly able to get one visual observation of this snakeduring the radio-tracking period when it was foundunder the outdoor bathroom in the Interpretive Kiosk.The maximum distance between the two farthestdocumented locations (i.e., between the originalcapture site in the Interpretive Kiosk Unit and theeasternmost location along the shore of the northernlagoon in the Facilities Unit) was about 570 m (0.35mi) along the dike.

Management Unit

Eastern

Fox Snake

Eastern

Garter

Snake

Butler's

Garter

Snake

Northern

Water

Snake

Northern

Ribbon

Snake

Brown

Snake

Unidentified

snake Total

Bean Field 0 0 0 0 0 0 0 0Campground Restoration 0 0 0 0 0 0 0 0

Corps CDF 0 1 1 0 0 0 0 2

Corps Volcano 0 0 0 0 0 0 0 0

Facilities 0 1 (3) 0 (1) 0 0 0 0 1 (4)

Headquarters 0 0 0 0 0 0 0 0

Hunt Club 0 1 (3) 0 0 0 1 0 2 (3)

Interpretive Kiosk 0 0 (2) 0 0 0 0 1 1 (2)

North Lagoons 0 0 0 0 0 0 0 0

Total 0 3 (8) 1 (1) 0 0 1 1 6 (9)

Note: The numbers in parentheses indicate the number of snakes observed during additional visual encounter surveys.


The two adult females that were captured togetherat a burrow along the paved trail and fencesurrounding the Corps CDF Unit on 19 June 2005utilized different parts of the park in 2005. The largerfemale (PIT tag #: 087 305 797, hereafter referred toas F79705) moved quite a bit during the radio-trackingperiod. The snake basically moved between the CorpsCDF Unit and the old field habitats along the lagoonson the west side of the Facilities Unit (Table 6 andFigure 7). The snake was located once somewhereinside the Corps CDF Unit based on the radio signalbut we did not have access into the unit and could notdetermine her exact location within the unit. We alsowere not able to get a signal and could not locate thissnake on 23 and 31 July, but we were able to locate heragain in the Facilities Unit on 7 August. This snakeexhibited greater movement (i.e., distances movedbetween locations and frequency of movements) thanany of the other snakes we have radio-tracked in thestudy to date. Some of the State Park StewardshipProgram actually commented that they had seen afairly large fox snake move across the Facilities Unitseveral times that summer. Interestingly, F79705 waslocated on 18 September back at the hole or burrowalong the fence of the Corps CDF Unit at which shewas initially captured, and this is where sheoverwintered.

F79705 was primarily found in herbaceousvegetation or grass in old field habitats, with 7 of 12locations (58%) in these habitat types (Table 6). Thissnake did not spend as much time underground duringthe radio-tracking period as F29305, and we were ableto get visual observations of this snake at most of thelocations to which it was tracked during the summer.The maximum distance between the two farthestdocumented locations (i.e., between the snake’scapture site along the fence of the Corps CDF Unit and

the southernmost location near the bridge in theFacilities Unit) was about 600 m (0.37 mi). Theperimeter or total distance among the documentedlocations was over 1,300 m (0.81 mi). This distanceshould still be considered an underestimate of the totaldistance this snake can travel within its home rangethough since this snake was only located weekly or bi-weekly during a portion of the snake’s active season.

The other adult female initially found at theburrow along the fence of the Corps CDF Unit (PITtag #: 087 320 124, hereafter referred to as F12405)was located mostly inside the Corps CDF Unit or inold field habitat just outside or near the Corps CDFUnit’s fence during the radio-tracking period in 2005(Table 7 and Figure 8). Because we did not haveaccess to the Corps CDF Unit in 2005, we were notable to determine her exact locations, movements andhabitats used for most of the summer. Interestingly, inSeptember, she also returned to the same hole orburrow along the paved trail and fence surrounding theCorps CDF Unit where she was initially found withF79705.

Overall, a total of eight different fox snakes havebeen implanted with transmitters and radio-trackedfrom 2003 to 2005. Of these, one fox snake was radio-tracked in 2003, three in 2004 and four in 2005. Onlytwo snakes have been radio-tracked over multipleactive seasons, but none have been tracked ormonitored over multiple winters. Almost all of theradio-telemetry locations to date have been along thedike in the southeast portion of the Hunt Club Unit,along the entire length of the Interpretive Kiosk Unitand along the lagoon in the northwestern portion of theFacilities Unit, with several locations in 2005 in oralong the southern half of the Corps CDF Unit and thenortheastern corner of the Facilities Unit (Figure 9).


Figure 4. Map of radio-telemetry locations for Fox Snakes J54904 (as indicated by the red dots), F29305 (purple dots),F79705 (yellow dots), and F12405 (blue dots) in Sterling State Park in 2005.

Hunt Club Unit

Interpretive Kiosk Unit

Facilities Unit

Corps CDFUnit


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Kio

sk

W. s

ide

of tr

ail,

N. o

f pa

vilio

n, o

ld f

ield

nea

r sh

orel

ine,

by

cotto

nwod

, do

gwoo

d, r

eed

cana

ry g

rass

Und

ergr

ound

NU

nkno

wn

41.9

1215

000

-83.

3427

0000

F266

0278

F, 5

0% s

un,

5-10

mph

Stro

ng s

igna

l with

cor

d bu

t w

eak

sign

al w

ithou

t cor

d,

pres

umed

stil

l und

ergr

ound

304

/29/

2005

Inte

rpre

tive

Kio

skPS

S/ g

rass

Gra

ss, s

ame

gene

ral a

rea

as

4/5

and

4/17

NU

nkno

wn

41.9

1215

000

-83.

3427

0000

54F,

ove

rcas

t, 0-

5mph

Susp

ect d

ead

407

/02/

2005

Inte

rpre

tive

Kio

skPS

S/O

LD

Her

bace

ous

YR

estin

g41

.915

4833

3-8

3.34

0400

0026

603

80-8

2F, 7

5%

sun,

3-5

mph

Snak

e=23

5g, S

VL

=82c

m,

tail=

14cm

507

/08/

2005

Inte

rpre

tive

Kio

skO

LD

Her

bace

ous

NU

nkno

wn

41.9

0000

000

-83.

3400

3333

80

F, li

ght r

ain,

6-

10m

ph

607

/14/

2005

Inte

rpre

tive

Kio

skO

LD

Her

bace

ous

NU

nkno

wn

41.9

0000

000

-83.

3400

3333

82F,

ove

rcas

t, 5-

10m

ph

707

/23/

2005

Inte

rpre

tive

Kio

skO

LD

Her

bace

ous/

un

derg

roun

dN

Unk

now

n41

.915

7666

7-8

3.34

0333

3326

604

82F,

90%

sun

, 3-

5mph

Mov

ing,

then

wen

t un

derg

roun

d

807

/31/

2005

Inte

rpre

tive

Kio

skO

LD

Her

bace

ous

YU

nkno

wn

41.9

1560

000

-83.

3404

8333

78F,

cle

ar, 3

-5m

phSn

ake

look

ed g

ood

908

/07/

2005

Inte

rpre

tive

Kio

skO

LD

Her

bace

ous

NU

nkno

wn

41.9

1201

667

-83.

3426

3333

F266

0582

F, c

lear

, 0m

phU

nder

grou

nd in

hol

e

1008

/15/

2005

Inte

rpre

tive

Kio

skO

LD

Her

bace

ous

YB

aski

ng/

fora

ging

41.9

1361

667

-83.

3416

1667

F266

0678

F, 2

0% s

un,

5-10

mph

Snak

e lo

oked

goo

d

1108

/21/

2005

Inte

rpre

tive

Kio

skPS

SR

ock

NR

estin

g41

.914

4000

0-8

3.34

1466

67F2

6607

80F,

100

%

sun,

5-1

0 m

phIn

roc

k ou

tcro

ppin

g

1208

/26/

2005

Inte

rpre

tive

Kio

skPS

SR

ock

NR

estin

g41

.914

2000

0-8

3.34

1533

33F2

6608

79F,

100

%

sun,

0-3

mph

Hid

ing

in r

ocks

on

edge

of

wat

er

1309

/02/

2005

Inte

rpre

tive

Kio

skPS

S/ d

ogw

ood

Roc

kN

Res

ting

41.9

1223

333

-83.

3427

3333

F266

0974

F, 1

00%

su

n, 5

-8m

phD

eep

unde

rgro

und

1409

/08/

2005

Unk

now

nU

nkno

wn

Unk

now

nN

Unk

now

nN

o G

PS p

oint

76F,

100

%

sun,

3-5

mph

Cou

ld n

ot f

ind

snak

e

1509

/18/

2005

Unk

now

nU

nkno

wn

Unk

now

nN

Unk

now

nN

o G

PS p

oint

82F,

65%

sun

, 3-

5mph

Bat

tery

may

be

dead

1 Hab

itat:

OL

D =

old

fie

ld, P

EM

= p

alus

trin

e em

erge

nt w

etla

nd, P

SS =

pal

ustr

ine

scru

b-sh

rub,

PFO

= p

alus

trin

e fo

rest

, PO

W =

pal

ustr

ine

open

wat

er,

USS

= u

plan

d sc

rub-

shru

b, U

FO =

upl

and

fore

st2 V

isua

l?: T

his

indi

cate

s w

heth

er v

isua

l obs

erva

tion

of th

e sn

ake

was

obt

aine

d (Y

es/N

o)3 L

atitu

de a

nd L

ongi

tude

: Exp

ress

ed in

dec

imal

deg

rees

Tabl

e 4.

Sum

mar

y of

radi

o-te

lem

etry

loca

tions

and

hab

itats

for F

ox S

nake

J549

04 in

Ste

rling

Sta

te P

ark

in 2

005.


J549042005 and 2004

Figure 5. Map of radio-telemetry locations for Fox Snake J54904 in Sterling State Park in 2005 (as indicated by thered dots) and some of the radio-telemetry locations from 2004 (green dots).

Interpretive Kiosk Unit

4/5/05&

9/2/05

Facilities Unit


Locati

on

Date

Un

itH

ab

itat1

Mic

roh

ab

itat

Vis

ual?

2B

eh

avio

rL

ati

tud

e3

Lon

git

ud

e3

GP

S W

ayp

t.W

eath

er

Com

men

ts

106

/14/

2005

Inte

rpre

tive

Kio

skPS

S-sc

rub,

will

owH

erba

ceou

sY

Res

ting

41.9

1688

333

-83.

3395

5000

77F,

100

%su

n, 5

-8m

ph

Cap

ture

site

- f

ound

with

adu

lt m

ale

fox

snak

e PI

T ta

g #

087

293

539;

sur

gery

on

6/16

, re

leas

ed o

n 6/

22

206

/27/

2005

Inte

rpre

tive

Kio

sk

Roc

k ri

prap

on

shor

e ad

jace

nt to

dog

woo

d sh

rubs

Und

er r

ocks

NU

nkno

wn

41.9

1866

667

-83.

3387

3333

F499

0185

-90F

, 100

% s

un, 0

-5m

phIn

hol

e in

roc

ks

307

/02/

2005

Inte

rpre

tive

Kio

sk

Roc

k ri

prap

on

shor

e ad

jace

nt to

dog

woo

d sh

rubs

Und

er r

ocks

NU

nkno

wn

41.9

1870

000

-83.

3386

8333

4990

280

-82F

, 100

% s

un, 0

-5m

phSa

me

spot

as

last

tim

e

407

/08/

2005

Inte

rpre

tive

Kio

skU

nder

bat

hroo

mU

nder

grou

ndY

Unk

now

n41

.919

1333

3-8

3.33

8550

00F4

9903

82F,

ove

rcas

t, 0-

5mph

507

/14/

2005

Faci

litie

sPS

S -

shru

bsR

ock

NU

nkno

wn

41.9

1878

333

-83.

3355

8333

F499

0482

F, o

verc

ast/h

azy,

5-

10m

ph

607

/23/

2005

Faci

litie

sR

ocks

at s

hore

Rip

rap

NU

nkno

wn

41.9

1876

667

-83.

3356

8333

F499

0582

F, 9

0% s

un, 3

-5m

phPr

obab

ly b

aski

ng b

efor

e w

e ap

proa

ched

707

/31/

2005

Faci

litie

sSh

orel

ine

Rip

rap/

un

derg

roun

dN

Unk

now

n41

.919

7000

0-8

3.33

7666

67F4

9906

80F,

100

% s

un, 3

-5m

ph

808

/07/

2005

Faci

litie

sR

ocks

at s

hore

Rip

rap/

shr

ubN

Unk

now

n41

.919

1500

0-8

3.33

6300

00F4

9907

80F,

cle

ar, 3

-5m

ph

908

/15/

2005

Faci

litie

sR

ocks

at s

hore

Rip

rap/

un

derg

roun

dN

Unk

now

n41

.919

5833

3-8

3.33

7433

33F4

9908

79F,

25%

sun

, 3-5

m

ph

1008

/21/

2005

Faci

litie

sR

ocks

at s

hore

Rip

rap

NU

nkno

wn

41.9

1953

333

-83.

3372

8333

F499

0982

F, 1

00%

sun

, 5-1

0 m

ph

1108

/26/

2005

Faci

litie

sR

ocks

at s

hore

Rip

rap

NU

nkno

wn

41.9

1951

667

-83.

3370

3333

F499

1082

F, 1

00%

sun

, 0-3

m

phV

ery

clos

e to

last

loca

tion

1209

/02/

2005

Faci

litie

sR

ocks

at s

hore

Rip

rap

NU

nkno

wn

41.9

1963

333

-83.

3375

3333

F499

1175

F, 1

00%

sun

, 8-

12m

phM

oved

und

ergr

ound

as

we

appr

oach

ed

1309

/08/

2005

Inte

rpre

tive

Kio

sk

PSS

- ~1

50 f

t fro

m

park

ing

lot i

n D

ogw

ood

and

grap

evin

eSc

rub

shru

bN

Unk

now

n41

.917

2833

3-8

3.33

9150

00F4

4912

76F,

100

% s

un, 3

-5m

ph

1409

/18/

2005

Inte

rpre

tive

Kio

skPS

SSh

rub

NU

nkno

wn

41.9

1825

000

-83.

3391

8333

F449

1382

F, 6

5% s

un, 3

-5m

ph

1 Hab

itat:

OL

D =

old

fie

ld, P

EM

= p

alus

trin

e em

erge

nt w

etla

nd, P

SS =

pal

ustr

ine

scru

b-sh

rub,

PFO

= p

alus

trin

e fo

rest

, PO

W =

pal

ustr

ine

open

wat

er,

USS

= u

plan

d sc

rub-

shru

b, U

FO =

upl

and

fore

st2 V

isua

l?: T

his

indi

cate

s w

heth

er v

isua

l obs

erva

tion

of th

e sn

ake

was

obt

aine

d (Y

es/N

o)3 L

atitu

de a

nd L

ongi

tude

: Exp

ress

ed in

dec

imal

deg

rees

Tabl

e 5.

Sum

mar

y of

radi

o-te

lem

etry

loca

tions

for F

ox S

nake

F29

305

in S

terli

ng S

tate

Par

k in

200

5.


F293052005

Figure 6. Map of radio-telemetry locations for Fox Snake F29305 in Sterling State Park in 2005,as indicated by the purple dots.

Interpretive KioskUnit

9/18/05

6/14/05

Boat Launch

Facilities Unit


Locati

on

Date

Un

itH

ab

itat1

Mic

roh

ab

itat

Vis

ual?

2B

eh

avio

rL

ati

tud

e3

Lon

git

ud

e3

GP

S W

ayp

t.W

eath

er

Com

men

ts

106

/19/

2005

Cor

ps

CD

F

USS

/pav

ed tr

ail -

w

here

pav

ed tr

ail

turn

s to

war

d th

e ea

st

Hol

e/bu

rrow

al

ong

pave

d as

phal

t tra

ilY

Bas

king

41.9

1365

000

-83.

3331

6667

72-7

6F, 2

5-75

% s

un, 0

-3m

ph

Cap

ture

site

- a

t hol

e/bu

rrow

w

here

two

othe

r fo

x sn

akes

w

ere

also

fou

nd th

is y

ear;

su

rger

y 6/

21; r

elea

sed

6/27

; sh

ed w

hile

hel

d

207

/02/

2005

Faci

litie

s

OL

D -

old

fie

ld,

gras

ses

and

wild

flow

ers

Her

bace

ous

YT

rave

ling

41.9

1346

667

-83.

3362

1667

F479

01

85-0

90F,

10

0% s

un, 0

-5m

ph

307

/08/

2005

Cor

ps

CD

F/

Faci

litie

s

USS

- in

hol

e w

here

pav

ed tr

ail

turn

s

Hol

e/bu

rrow

al

ong

pave

d as

phal

t tra

ilN

Unk

now

n41

.913

4833

3-8

3.31

9783

33F4

9702

76F,

ove

rcas

t, 0-

5mph

407

/14/

2005

Faci

litie

sO

LD

- n

ear

wat

er

by s

idew

alk

Her

bace

ous

YB

aski

ng/

trav

elin

g41

.913

4000

0-8

3.33

7333

33F4

9703

82F,

ove

rcas

t, 5-

10m

phA

ppea

rs to

hav

e re

cent

ly e

aten

507

/23/

2005

Unk

now

nU

nkno

wn

Unk

now

nN

Unk

now

nN

o G

PS p

oint

82F,

90%

sun

, 3-

5mph

No

sign

al, c

ould

not

loca

te

snak

e

607

/31/

2005

Unk

now

nU

nkno

wn

Unk

now

nN

Unk

now

nN

o G

PS p

oint

80F,

100

%

sun,

3-5

mph

No

sign

al, c

ould

not

loca

te

snak

e

708

/07/

2005

Faci

litie

sO

LD

- n

ear

brid

ge o

n SE

Her

bace

ous

YFo

ragi

ng/

bask

ing

41.9

1115

000

-83.

3399

5000

F497

0482

F, c

lear

, 0-

3mph

Snak

e lo

oks

good

808

/15/

2005

Faci

litie

sO

LD

Her

bace

ous/

gra

ssY

Fora

ging

/ ba

skin

g41

.914

0000

0-8

3.33

7016

67F4

9705

78F,

20%

sun

, 5-

10m

phSn

ake

look

s go

od, w

ent i

nto

hole

at b

ase

of p

ine

tree

908

/21/

2005

Cor

ps

CD

FO

LD

Gra

ssY

Res

ting

41.9

1312

075

-83.

3339

9721

F497

0681

F, 1

00%

su

n, 0

-3m

phR

eady

to s

hed

1008

/26/

2005

Cor

ps

CD

FU

nkno

wn

- in

side

fe

nce

Unk

now

nN

Unk

now

nN

o G

PS p

oint

82F,

100

%

sun,

0-3

mph

1109

/02/

2005

Cor

ps

CD

FO

LD

Gra

ssY

Bas

king

/ fo

ragi

ng41

.913

4333

3-8

3.33

4666

67F4

9707

75F,

100

%

sun,

5-8

mph

Wen

t int

o ho

le in

gro

und

1209

/08/

2005

Faci

litie

sO

LD

Gra

ssY

Bas

king

/ re

stin

g41

.912

7666

7-8

3.33

3233

33F4

9708

76F,

100

%

sun,

3-5

mph

Loo

ks g

ood

1309

/18/

2005

Cor

ps

CD

FO

LD

Hol

e/bu

rrow

al

ong

pave

d as

phal

t tra

ilN

Unk

now

n41

.913

5000

0-8

3.33

3133

33F4

9709

82F,

65%

sun

, 0-

3mph

1 Hab

itat:

OL

D =

old

fie

ld, P

EM

= p

alus

trin

e em

erge

nt w

etla

nd, P

SS =

pal

ustr

ine

scru

b-sh

rub,

PFO

= p

alus

trin

e fo

rest

, PO

W =

pal

ustr

ine

open

wat

er,

USS

= u

plan

d sc

rub-

shru

b, U

FO =

upl

and

fore

st2 V

isua

l?: T

his

indi

cate

s w

heth

er v

isua

l obs

erva

tion

of th

e sn

ake

was

obt

aine

d (Y

es/N

o)3 L

atitu

de a

nd L

ongi

tude

: Exp

ress

ed in

dec

imal

deg

rees

Tabl

e 6.

Sum

mar

y of

radi

o-te

lem

etry

loca

tions

for F

ox S

nake

F79

705

in S

terli

ng S

tate

Par

k in

200

5.


F797052005

Figure 7. Map of radio-telemetry locations for Fox Snake F79705 in Sterling State Park in 2005, as indicated bythe yellow dots.

Corps CDF Unit

Facilities Unit

8/7/05

6/19/05&

9/18/05


Lo

ca

tio

nD

ate

Un

itH

ab

ita

t1M

icro

ha

bit

at

Vis

ua

l?2

Beh

av

ior

La

titu

de

3L

on

git

ud

e3

GP

S W

ay

pt.

Wea

ther

Co

mm

en

ts

106

/19/

2005

Cor

ps C

DF

USS

- w

here

pav

ed

trai

l tur

ns to

war

d th

e ea

stH

ole/

burr

ow a

long

pa

ved

asph

alt t

rail

YB

aski

ng41

.913

6500

0-8

3.33

3166

6772

-76F

, 25-

75%

su

n, 0

-3m

ph

Cap

ture

site

- a

t hol

e or

bur

row

w

here

two

othe

r fo

x sn

akes

wer

e al

so f

ound

this

yea

r; s

urge

ry 6

/21;

re

leas

ed 6

/27;

she

d w

hile

hel

d

207

/02/

2005

Cor

ps C

DF

USS

- w

here

pav

ed

trai

l tur

ns to

war

d th

e ea

stSa

me

hole

as

on

6/19

/ und

ergr

ound

NU

nkno

wn

41.9

1350

000

-83.

3331

3333

F399

0180

-82F

, 100

% s

un,

0-5m

ph

307

/08/

2005

Cor

ps C

DF

PSS/

USS

- s

crub

-sh

rub

insi

de f

ence

Unk

now

nN

Unk

now

nN

o G

PS p

oint

72-7

4F, o

verc

ast,

light

rai

n, 0

-5 m

ph

407

/14/

2005

Cor

ps C

DF

PSS/

USS

- s

crub

-sh

rub

insi

de f

ence

Unk

now

nN

Unk

now

nN

o G

PS p

oint

82F,

ove

rcas

t, 5-

10

mph

507

/23/

2005

Cor

ps C

DF

PSS/

USS

- s

crub

-sh

rub

insi

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Figure 8. Map of radio-telemetry locations for Fox Snake F12405 in Sterling State Park in 2005, as indicatedby the blue dots.

F124052005

Facilities Unit

Corps CDF Unit

6/19/05&

9/18/05


Sterling State ParkAll Fox Snake Locations2003-2005

Figure 9. Map of all Eastern Fox Snake locations based on visual encounter surveys (as indicated by the tri-angles) and radio-telelmetry (as indicated by the circles or dots) in Sterling State Park in Monroe County,Michigan from 2003-2005.


DISCUSSION

The total number of Eastern Fox Snakeobservations documented during visual encountersurveys in 2005 was very small, similar to surveyresults in 2003 and 2004. Only six observations ofEastern Fox Snakes were documented in over 90 hoursand over 170 person-hours of surveys in 2005. Overall,surveys from 2003–2005 at Sterling State Park havedocumented a total of only 23 Eastern Fox Snakeobservations and 21 individual snakes in almost 500hours and over 600 person-hours of surveys (Table 8).The number of fox snake observations documentedduring surveys in 2005 was lower than the number offox snakes found in 2004 but similar to that found in2003 (Table 8). In order to calibrate for differentsurvey effort and to facilitate comparisons of resultsamong years, detection frequencies based on numbersof fox snake observations per survey hour or perperson-hour can be calculated. Detection frequenciesfor all surveys combined (i.e., line-transect, time-constrained and additional VES) in 2005 were 0.05and 0.04 Eastern Fox Snake observations per surveyhour and per person-hour, respectively. These detectionfrequencies are lower than those for surveys in 2004(i.e., 0.09 and 0.07 observations per survey hour andper person- hour, respectively) but slightly higher orcomparable to those for surveys in 2003 (0.02observations per survey hour and per person-hour)(Table 8). Detection frequencies for just the line-transect and time-constrained VES combined wereagain highest for surveys conducted in 2004 andlowest for surveys in 2005 because no fox snakes weredocumented during these surveys in 2005 (Table 8).However, comparisons of detection frequencies shouldbe viewed with caution as species detectability can beinfluenced by relative abundance as well as a numberof other factors including habitat conditions, weatheror survey conditions, behavior of individuals, age ofindividuals, and surveyor bias (Thompson et al. 1998).In general, overall detection frequencies were similarand very low across all three years of the study.

A number of factors may have contributed to thelow number of Eastern Fox Snakes that have beendocumented during visual encounter surveys inSterling State Park from 2003-2005. First, the EasternFox Snake population within Sterling State Park and/orindividual management units may be fairly small. Thisis plausible given apparently limited and degradedhabitat and the high level of human use anddisturbance within the park. The fox snake populationat Sterling also continues to be threatened by road

mortality and intentional and unintentional killing byhumans. Also, prior to initiation of recent habitatrestoration efforts and this monitoring study, asignificant amount of habitat disturbance and loss hadalready occurred in areas within the park in which foxsnakes had occurred historically. Examples of thiswould include removal of the old campground fromthe Campground Restoration Unit and removal of thepark headquarters from the Corps Volcano Unit. Theseactions and associated activities might have alreadyadversely impacted the fox snake population withinthese units and the park in general. However, despitethe small numbers of fox snakes that were locatedduring surveys from 2003-2005, snakes of differentage classes were found including young snakes,providing evidence that some reproduction orrecruitment has occurred in the fox snake population inthe park. We also keep finding new snakes during oursurveys, and additional snake observations continue tobe documented by the Sterling State Park and/or StatePark Stewardship Program staff. The small number offox snake captures and recaptures to date precludedetermining fox snake relative abundance orpopulation density within the park at this time.

Aspects of the fox snake’s biology and ecologyalso may have contributed to the low number of foxsnake observations documented during visual surveysat Sterling State Park from 2003-2005. Snakes areoften cryptic in color and behavior and are also patchyin their distributions, both spatially and temporally(Ministry of Environment, Lands and Parks 1998).Both these factors can contribute to low detection ratesduring visual encounter surveys. Eastern Fox Snakescan be cryptic in color, behavior, and habitat use, andalso may have a patchy distribution temporally andspatially given the distribution of available habitatwithin the park. Radio- telemetry data from fox snakestracked at Sterling State Park from 2003-2005 indicatethat fox snakes at Sterling can spend a great deal oftime under cover or under ground during the activeseason in general and particularly during the hotsummer months (i.e., July and August). Eastern FoxSnakes and other snakes at Sterling State Park alsohave been found quite frequently under large concreteslabs, many of which can not be lifted or checked dueto their large size and weight. Radio-telemetry of foxsnakes at Sterling State Park also has demonstratedhow cryptic and difficult it can be to detect fox snakeseven when they are above ground. Fox snakes, evenlarge individuals, can be completely hidden from view


2003 2004 2005 Total

Total fox snake observations for all surveys 6 11 6 23Total fox snake observations for LTS and TCS 4 7 0 11Total fox snake observations for AVS 2 4 6 12New fox snakes observed during all surveys 6 9 6 21New fox snakes observed during LTS and TCS 4 5 0 9New fox snakes observed during AVS 2 2 5 9New fox snakes captured during all surveys 6 9 5 20New fox snakes captured during LTS and TCS 4 5 0 9New fox snakes captured during AVS 2 2 5 9Fox snake recaptures during all surveys 0 2 0 2Fox snake recaptures during LTS and TCS 0 2 0 2Fox snake recaptures during AVS 0 0 0 0Survey effort - all surveys (survey hours) 290 100 91 481Survey effort - LTS & TCS (survey hours) 92 70 81 243Survey effort - AVS (survey hours) 198 30 10 238Survey effort - all surveys (person-hours) 290 159 171 620Survey effort - LTS & TCS (person-hours) 92 96 157 345Survey effort - AVS (person-hours) 198 64 14 276Detection frequency - # fox snake observations/survey hour for all surveys 0.02 0.09 0.05 0.05Detection frequency - # fox snake observations/survey hour for LTS & TCS 0.04 0.07 0.00 0.05Detection frequency - # fox snake observations/survey hour for AVS 0.01 0.07 0.50 0.05Detection frequency - # fox snake observations/person-hour for all surveys 0.02 0.07 0.03 0.04Detection frequency - # fox snake observations/person-hour for LTS & TCS 0.04 0.07 0.00 0.03Detection frequency - # fox snake observations/person-hour for AVS 0.01 0.06 0.36 0.04

Surveys: LTS = line-transect visual encounter surveysTCS = time-constrained visual encounter surveysAVS = additional visual encounter surveys

Note: For 2006 detection frequencies, only used 5 fox snake observations because 1 fox snake observation was recorded while tracking a transmittered snake.

Table 8. Summary of results of Eastern Fox Snake surveys conducted by MNFI from 2003-2005 inSterling State Park in Monroe County, Michigan.


when they are under vegetation or thatch that is evenonly several inches deep. In 2006, surveyors did notdetect and walked by several transmittered fox snakesduring line-transect and time-constrained surveys.

Habitat changes or conditions in some of themanagement units may have contributed to the lownumber of fox snake observations documented duringvisual surveys at Sterling State Park from 2003-2005.Habitat conditions in some management units in thepark during this study were either unsuitable for foxsnakes or made it very difficult to detect fox snakesduring visual surveys. For example, habitat restorationefforts in the Campground Restoration Unit removedall ground vegetation and topsoil during the fall/winterof 2003. Bare ground and very open habitat conditions,which did not provide suitable habitat for fox snakes,comprised a good portion of this unit during thesurveys in 2004 and 2005. Additionally, the availabilityof artificial cover was greatly reduced in the CorpsVolcano Unit after surveys in 2003 which may havecontributed to lower numbers of fox snakes found inthis unit in 2004 and 2005. Some of the managementunits including the Corps Volcano, Hunt Club andFacilities units also contained areas that had very tall,dense ground vegetation which made it very difficult todetect fox snakes during visual surveys in these areas.

Finally, survey conditions or methodology mayhave contributed to the low number of fox snakeobservations documented during visual surveys atSterling State Park. For example, timing of the surveysmay have been an important factor. The best time tosurvey for fox snakes is typically May and June whenthe snakes are most active and most visible since thevegetation is generally shorter and/or less dense(Harding 1997, Lee 2000). Also, Eastern Fox Snakesare generally active throughout the day, but duringperiods of intense heat, fox snakes may become morenocturnal (Evers 1994). Consequently, the line-transectand time-constrained surveys at Sterling may havedocumented such low numbers of fox snakes becausethey were conducted during late summer and early fallfrom late July or early August through mid-Septemberwhen snakes were spending more time under cover orunderground or perhaps were more active at night dueto warm weather conditions during the day. Also, foxsnake detection frequencies for additional visualencounter surveys conducted during the spring andearly summer (i.e., May and June) in 2004 and 2005were higher than those for line-transect and time-constrained surveys in 2004 and 2005 and additionalVES in 2003 which were all conducted during latesummer and fall (i.e., August and September),

providing further evidence that timing of the surveysmay have led to low numbers of fox snakes found.Surveys for fox snakes at Sterling State Park in 2006as part of a continuing and expanded study also foundmore snakes during additional VES in June thanduring line-transect and time-constrained surveys inAugust and early September. Other researchers alsohave reported difficulty in seeing or finding fox snakesduring late summer and early fall (Bekker pers.comm.). These results strongly suggest that springsurveys may be more productive than late summer orearly fall surveys and should be considered in futuremonitoring efforts for this species.

In addition to timing of surveys within an activeseason, annual weather conditions immediately priorto and during surveys also can affect survey results.The weather during the summer of 2005 prior to andduring fox snake surveys was characterized by veryhigh air temperatures and little rain. These weatherconditions may have contributed to 2005 survey resultsin which no fox snakes and very few other snakes werefound during line-transect and time-constrainedsurveys since snakes and other herps are generally notas active or visible during hot, dry weather (Karns1986). Other researchers in the region also reportedfinding reduced numbers or fewer snakes in generalduring the 2005 field season. Overall, the low numbersof Eastern Fox Snakes documented during surveys atSterling State Park to date were likely a result of acombination of all the factors described earlier.

Although survey results from 2003-2005 may notbe conclusive in determining potential impacts ofhabitat restoration efforts on the fox snake populationin Sterling State Park in terms of relative abundancebecause of small sample sizes, survey and radio-telemetry results to date suggest that fox snake use ofparticular management units within the park may havebeen impacted to some degree. A majority of the radio-telemetry locations and locations at which fox snakeswere found during surveys occurred along the dike inthe southeast corner of the Hunt Club Unit and allalong the Interpretive Kiosk Unit and along the lagoonin the northwest portion of the Facilities Unit (Figure9). These locations were in areas that had undergonesome habitat restoration but generally had not beendramatically altered. Prior to this study, Eastern FoxSnakes had been documented in these managementunits as well as other units in the park such as theCampground Restoration Unit. Surveys and radio-telemetry from 2003-2005 did not document any foxsnakes in the Campground Restoration Unit. However,park staff and contractors reported seeing at least one


fox snake in this unit during the study. Restorationefforts in the Campground Unit removed a significantamount of the soil, vegetation and available cover inthis unit in 2003 and dramatically changed habitatconditions in this unit which likely impacted foxsnakes’ use of this area. Another unit in whichsignificant habitat restoration activities have beenconducted is the Bean Field Unit. The northern third orhalf of this unit has been planted with several nativeprairie plant species to provide a local seed or plantsource for habitat restoration efforts on-site. Suitablehabitat appears to be available at least in portions ofthis management unit (e.g., the southern orsoutheastern portions of the unit), but no fox snakeswere found in this unit during surveys from 2003-2005. In 2006, one of the transmittered fox snakes waslocated a few times in the Bean Field Unit but only inthe southwestern portion of the unit that had not beenplanted or heavily disturbed during habitat restorationefforts. However, some fox snakes were found in areasthat had been sprayed and burned for invasive speciescontrol, indicating they can certainly tolerate somehabitat restoration activities.

The radio-telemetry portion of the study providedadditional insights into Eastern Fox Snake ecology anddistribution at Sterling State Park. Similar to telemetryresults in 2003 and 2004, the fox snakes tracked in2005 were all located primarily along the dike or alongthe edge of the lagoons and generally near the water oremergent wetland’s edge (i.e., generally within 1-3 mbut further away in some cases). Maximum distancesbetween known or documented locations for the foursnakes tracked in 2005 were very similar to thosedocumented for radio-tracked snakes in 2003 and2004. The radio-telemetry results from 2005 alsoindicate that fox snakes may exhibit some site fidelityand return to the same hibernation site from one winterto the next. The fox snakes returned to the same areasor in some cases the same burrows in the fall of 2005at which they were initially captured in the spring. Thefox snake that was radio-tracked in 2004 and 2005utilized a similar area or home range within the park in2004 and 2005 and returned to at least the samegeneral area for overwintering. Fox snakes also mayemerge from their overwintering sites a little later inthe spring than other snakes, and may stay near theiroverwintering sites for some time after emergence.One of the fox snakes that was radio-tracked in 2004was still located at its overwintering site at the end ofApril in 2005. Also, several of the snakes radio-trackedin 2005 overwintered in or near their initial capturesites at which they were first observed and captured in

mid-June of 2005, indicating that fox snakes may stayat or near their overwintering sites until mid-June inthe spring. Fox snakes also may enter theiroverwintering sites earlier than expected. During thisstudy, most radio-tracked fox snakes were at theiroverwintering sites by mid-September (e.g., Sept. 18 in2005). It is important to keep in mind though thatemergence and ingress times can vary annuallydependent upon local weather conditions.

Similar to survey and radio-telemetry results in2003 and 2004, the Eastern Fox Snakes that werefound during surveys or were radio-tracked in 2005primarily utilized open upland and wetland habitatssuch as old field, palustrine emergent wetland andpalustrine scrub-shrub habitats. Snakes were oftenfound in or under open or thick grass, shrubs or denseemergent vegetation. Similar to snakes tracked in 2003and 2004, fox snakes tracked in 2005 were primarilyfound on or along the side of paved trails, in or underconcrete slabs or rock riprap along the shore of theopen water lagoons, underground in tree root networksor burrows, or on the surface or underground along theembankment of the dike. Again, cover was veryimportant for the fox snakes in the study. The mostimportant habitat feature required by snakes is cover orshelter (Ministry of Environment, Lands and Parks1998). The use of cover, dense vegetation andunderground retreats by Eastern Fox Snakes mayrepresent an important strategy or adaptation forcoping with hot weather conditions, avoiding detectionby predators and/or surviving in heavily used ordisturbed habitats (Lee 2004). The use of natural andartificial cover by fox snakes at Sterling State Parksuggests that placing cover boards in areas withsuitable habitat may be an effective survey techniquefor this species (Lee 2004).

Most of the fox snakes that were tracked duringthe radio-telemetry study hibernated or overwinteredunderground along the dike or paved trail in the HuntClub Unit. It was presumed that the snakesoverwintered in some sort of burrow or tree rootnetwork but this could not be determined based on thesnakes’ signals. Two of the snakes in 2005overwintered in a burrow along the paved trail alongthe fence of the Corps CDF Unit in the northeastcorner of the Facilities Unit. All the hibernation sitesdocumented to date were in areas elevated above thewater or emergent wetlands although a few of theoverwintering sites were located fairly low along thedike’s embankment. Other snake species such as theeastern massasauga recently also have beendocumented as hibernating in uplands or transitional


areas between wetlands and uplands (Wildman pers.comm., Sage pers. comm.). Eastern Massasaugas alsohave been found to hibernate submerged or partiallysubmerged in water in crayfish, small mammal orother burrows. It is unknown if Eastern Fox Snakesspecifically use crayfish or other animal burrows or ifthey hibernate submerged in water. Protection ofsuitable hibernacula is critical for maintaining foxsnake populations. Thus, known hibernacula withinSterling State Park (e.g., the dike in the Hunt ClubUnit) should be maintained until more is known aboutfox snake overwintering ecology.

Although the numbers of fox snakes found duringsurveys from 2003-2005 have not changeddramatically, the number of observations of othersnake species documented during visual surveys atSterling State Park has drastically declined during thistime period. Over 270 observations of other snakespecies were documented during surveys in 2003. Only69 observations of other snake species weredocumented during surveys in 2004. In 2005, only 15observations of other snake species were documentedfor all visual surveys combined. In particular, thenumber of eastern and Butler’s garter snakes havedecreased significantly, from 121 and 110 observationsof these species, respectively, in 2003 to only 11 and 2observations of these species, respectively, in 2005.The Facilities, Hunt Club, Corps Volcano and CorpsCDF units contained the highest numbers ofobservations of other snake species in 2003. In 2004,80-97% fewer observations of other snake specieswere documented in these four units, and 33-95%fewer in the other units. This may have been due toimpacts from the restoration activities, climatic

conditions during the spring and summer of 2004 (i.e.,cool, wet spring followed by cool, dry summer) and/ordifferent surveyors. Observations of other snakespecies should continue to be documented andmonitored during future surveys.

Finally, although study results from Sterling StatePark in 2003-2005 indicate that Eastern Fox Snakescan inhabit highly disturbed and actively managedsites, the long-term viability of this population remainsunknown. The fox snake population within the parkcontinues to face a number of threats including highlydegraded and limited habitat (at least currently);population isolation; road mortality; intentional andunintentional killing, harassing or disturbance bypeople; incidental take or impacts due to parkmanagement activities (e.g., mowing of large areasreduce or minimize areas with sufficient cover forshelter, foraging, dispersal, and safe passage orprotection from predators); and predation. Theongoing restoration efforts may create additionalhabitat for fox snakes in the future but also can posethreats to the park’s fox snake population in the shortterm. Given that little is currently known about thestatus and structure (i.e., recruitment rate, sustainablemortality rate, etc.) of the fox snake population inSterling State Park, efforts should continue tominimize threats to the population and the snakemortality rate within the park. Since fox snakes havebeen found primarily in the Hunt Club, InterpretiveKiosk and Facilities units during this study,consideration of management activities and ways tominimize potential adverse impacts of these activitieson Eastern Fox Snakes is especially warranted in theseunits.

FUTURE WORK

Continued monitoring of Eastern Fox Snakes atSterling State Park is needed to continue to assess andprovide insight into potential impacts of recent habitatrestoration efforts on the fox snake population in thepark. A study funded by the Michigan DNR’s WildlifeDivision was initiated in 2006 to continue the foxsnake monitoring and radio-telemetry study at SterlingState Park. Survey and monitoring efforts havebasically utilized the same methodology as surveysfrom 2003-2005. Additional surveys have beenconducted in the spring and early summer to comparewith results from late summer surveys to evaluatetiming and effectiveness of surveys and to try toincrease the numbers of fox snake observations. Cover

board surveys also were added to the study. The radio-telemetry portion of the study also has been expandedwith more snakes added to the study. This study hasbeen conducted in conjunction with a similar study ofEastern Fox Snakes at The Nature Conservancy’s ErieMarsh Preserve, located about 10 miles south ofSterling State Park. Erie Marsh also has beenundergoing habitat management and restoration in asimilar but somewhat less disturbed, larger and morecontiguous landscape context. Sharing and comparingresults among the two study sites will provideadditional insight into Eastern Fox Snake ecology andresponse to habitat management activities.


REFERENCES

Albert, D. A. 1995. Regional landscape ecosystems ofMichigan, Minnesota, and Wisconsin: A workingmap and classification. USDA Forest Service,North Central Forest Experiment Station, GeneralTechnical Report NC-178.

Albert, D. A. 2001. Natural community abstract forGreat Lakes marsh. Michigan Natural FeaturesInventory, Lansing, MI. 11 pp.

Albert, D. A. and M. A. Kost. 1998. Naturalcommunity abstract for lakeplain wet prairie.Michigan Natural Features Inventory, Lansing, MI.4 pp.

Bekker, K. Personal communication. Toledo Zoo,Toledo, OH.

Cowardin, L. M., V. Carter, F. C. Golet and E. T.LaRoe. 1979. Classification of wetlands anddeepwater habitats of the United States. USFWS,Washington, D.C.

Ernst, C. H. and R. W. Barbour. 1989. Snakes ofEastern North America. George Mason UniversityPress, Fairfax, VA. 282 pp.

Evers, D. C., ed. 1994. Endangered and ThreatenedWildlife of Michigan. University of MichiganPress, Ann Arbor, MI. 412 pp.

Freedman, B. and P. M. Catling. 1979. Movements ofsympatric species of snakes at Amherstburg,Ontario. Canadian Field Naturalist 93:399-404.

Harding, J. H. 1997. Amphibians and Reptiles of theGreat Lakes Region. University of Michigan Press,Ann Arbor, MI. 378 pp.

Hardy, D. L., Sr. and H. W. Greene. 1999. Surgery onrattlesnakes in the field for implantation oftransmitters. Sonoran Herpetologist 12(3):25-27.

Karns, D. R. 1986. Field Herpetology Methods forthe Study of Amphibians and Reptiles inMinnesota. Occasional Paper No. 18, James FordBell Museum of Natural History, University ofMinnesota, MN. 88 pp.

Kingsbury, B. A. 2001. A survey protocol forcopperbelly water snakes (Nerodia erythrogasterneglecta) from northern populations. Unpublisheddocument, Indiana-Purdue University, Fort Wayne,IN. 5 pp.

Kingsbury, B. A., M. Standora and J. Gibson. 2001.Status of the eastern massasauga (Sistruruscatenatus catenatus) in Michigan. Unpublishedinterim report to the Michigan Department ofNatural Resources, Lansing, MI. 15 pp + appdx.

Kingsbury, B. A. and J. Sage. Personalcommunication. Indiana-Purdue University, Ft.Wayne, IN.

Lee, Y. 2000. Special animal abstract for Elaphevulpina gloydi (Eastern Fox Snake). MichiganNatural Features Inventory, Lansing, MI. 4 pp.

Lee, Y. 2004. Monitoring of Eastern Fox Snakes(Elaphe vulpina gloydi) in response to habitatrestoration at Sterling State Park in Michigan.Michigan Natural Features Inventory (MNFI)Report No. 2004-20. Unpublished report to theMichigan Department of Natural Resources, Parksand Recreation Bureau, Lansing, MI. 33 pp +appdx.

Lee, Y. and P. B. Pearman. 2004. Eastern Fox Snakemonitoring at Sterling State Park: 2003 ProgressReport. Michigan Natural Features Inventory(MNFI) Report No. 2004-01. Unpublished reportto the Michigan Department of Natural Resources,Parks and Recreation Bureau, Lansing, MI. 5 pp +appdx.

Michigan Natural Features Inventory. 2006. NaturalHeritage Biological and Conservation DataSystem. Consolidated by Michigan NaturalFeatures Inventory, Lansing, MI.

Ministry of Environment, Lands and Parks, ResourcesInventory Branch. 1998. Inventory methods forsnakes: Standards for Components of BritishColumbia’s Biodiversity No. 38. Prepared for theTerrestrial Ecosystems Task Force, ResourcesInventory Committee, Province of BritishColumbia, Canada. 50 pp.


Olson, J. A. 2002. Sterling State Park Natural FeaturesInventory and Management Recommendations.Report for the Michigan Department of NaturalResources, Parks and Recreation Bureau.Michigan Natural Features Inventory, Lansing, MI.6 pp.

Reinert, H. K. and D. Cundall. 1982. An improvedsurgical implantation method for radio-trackingsnakes. Copeia 1982:702-705.

Reinert, H. K. 1992. Radiotelemetric field studies ofpit vipers: data acquisition and analysis. In:Campbell, J. A. and E. D. Brodie Jr. (eds) Biologyof the Pit Vipers. Selva Press, Tyler, TX.

Rivard, D. H. 1976. The biology and conservation ofEastern Fox Snakes (Elaphe vulpine gloydi). M.S.Thesis, Carlton University, Ottawa, Canada.

Thompson, W. L., G. C. White and C. Gowan. 1998.Monitoring Vertebrate Populations. AcademicPress, Inc. San Diego, CA. 365 pp.

ACKNOWLEDGEMENTS

Funding for this project was provided by theMichigan Department of Natural Resources, Parks andRecreation Bureau, State Park Stewardship Programthrough a Great Lakes Coastal Restoration Grant. Thisproject would not have been possible without theassistance of many individuals. First, I would like tothank Rachel Osborn and David Mifsud for theirinvaluable field assistance with this project. I wouldlike to also acknowledge a number of volunteers whohelped Rachel and David in the field including MikeGrundler, Laurie Marzulla, Rachel Primeau, SeanZera, and Ashley Osborn. I am indebted to Dr. BruceKingsbury, Biology Department Chair at Indiana-Purdue University at Fort Wayne, for his ongoingtechnical consultation and generous assistance with theradio-telemetry portion of the study. Dr. Kingsbury’sexpert advice and assistance with this project havebeen invaluable and greatly appreciated. Dr. TaraMyers Harrison, veterinarian with Potter Park Zoo inLansing, Michigan, and Dr. Susan Stein and Dr. JamesSikarskie, veterinarians with Michigan StateUniversity, provided technical consultation andassistance with purchasing supplies. I also would liketo acknowledge the following MNFI staff for their

contributions to this project: Sue Ridge, AdministrativeAssistant, for her incredible patience and assistancewith purchasing supplies and project administration;Connie Brinson, Secretary, for processing travel andpurchase reimbursements; Lyn Scrimger, Budget andProject Management Specialist, for assistance withbudget and contract administration.; Helen Enander,MNFI’s expert GIS analyst, for her invaluableassistance with the maps and willingness to help at amoment’s notice; and Joelle Gehring, ZoologyProgram Leader, for reviewing this report andproviding general support and consultation. I alsowould like to thank the Sterling State Park staff forproviding access to the park, for reporting and pickingup fox snakes and other rare species for us, and fortheir interest and cooperation! Finally, I would like toespecially thank the State Park Stewardship Programstaff, Ray Fahlsing, Glenn Palmgren, Robert Clancy,and their seasonal staff, for their patience andassistance with this project, for keeping an eye out forfox snakes during their work, and for their concern andinterest in continuing to assess and address potentialimpacts of habitat restoration efforts on Eastern FoxSnakes at Sterling State Park.

A-1

APPENDICES

A-3

Appendix I. Maps of the locations of the line transects for the visualencounter surveys conducted by Michigan Natural Features Inventory

in all nine management units within Sterling State Parkin Monroe County, Michigan.

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Appendix II. 2005 Eastern Fox Snake Survey and Radio-Telemetry Data Form

A-16

Appendix II. Continued.

A-17

Appendix III. Michigan Natural Features Inventory (MNFI) Special Animal Survey Form

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monitoring of eastern fox snakes (pantherophis gloydi) in ... · monitoring of eastern fox snakes...

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