The Midden

Park News Great Basin National ParkNational Park ServiceU.S. Department of the Interior

Update on Bighorn Sheep

Summer 2004

The Resource Management Newsletter of Great Basin National Park

Volume 4 Issue 1

Two New MarmotColonies DiscoveredBy Rosaleen ConradTwo new marmot colonies were dis-covered in May in and near the park.These were important and excitingfinds, since pinyon-juniper forests areexpanding into sage-grassland habitat.As this happens, some small mammalpopulations are fluctuating, includingthe yellow-bellied marmot (Marmotaflaviventris).

Resource management is studyinghow small mammals respond tochanging habitat conditions and havestarted by conducting an inventory ofsmall mammal populations. Of par-ticular interest are marmot popula-tions, which a resurvey in Nevada lastyear found greatly reduced. Withinthe park, twelve individuals are lo-cated in Baker Creek and use theroad base to make their burrows.Additional marmot sightings have

Marmot on the lookout

Please turn to Page 2

been made in South Fork Big Washand Lehman Creek, but these popula-tions are not well documented.

During the week of May 24-28, twomore marmot populations were foundand confirmed. One was found in up-per Strawberry Creek and the otheroutside the park in the Schell Creekrange at McCoy Creek.

The population found at StrawberryCreek is a fairly large populationbased on the numerous piles of scatand burrows located on some largequartzite outcrops. This is slightlyunexpected habitat, but below it is themore typical sloped rocky meadowand talus habitat.

The McCoy Creek colony was iden-tified by finding a burrow site in con-

By Neal Darby

Our 2004 winter surveys for bighornsheep found 12 individuals. After along hike into Box Canyon to get abetter look we were able to identifythree ewes (adult females), threelambs, three young rams less than 4years old, and three mature ramsgreater than three years old. One ofthe mature rams was our familiargreen ear tagged ram. He was origi-nally released by the Nevada Depart-

ment of Wildlife on Mt. Moriah in1990 when he was two years old. Hecelebrated his 16th birthday this spring!

Seeing so many bighorn was greatnews because no bighorn could befound in the winter of 2003 and wefeared the worst. Small populationsare more prone to die-off from eventssuch as wildfires, avalanches or dis-

ease outbreaks. The sheep have beenknown to historically spend the winterin Box Canyon, but our survey in2003 failed to sight any, even whileusing a helicopter. One big differencebetween the winters of 2003 and2004 was snow cover. There wassubstantially more snow in 2004 than2003 and this likely determined justwhere the bighorn spend their win-ters. Now we just have to figure outwhere they spend winters with belowaverage snowfall.

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junction with the diagnostic marmotscat. This habitat was located in arocky meadow with a fairly steepslope, interspersed with large quartz-ite boulders at the base of which theburrows were typically found.

In looking at these two separate habi-tats it looks as though the typicalmarmot habitat is found on vegetatedtalus slopes or in meadows withrocky outcrops in expansive sage/steppe habitats. The rocks serve assupport for their burrows and also asgood sunbathing posts. Both habitatswere located on southern slopeswhere it would be warmer than onnorthern slopes. This is important dueto the fact that marmots hibernate fornine months of the year, and it is nec-essary not to waste any energy ingenerating more heat than is abso-lutely necessary.

Since marmots hibernate for most ofthe year in underground burrows,locating them can be problematic dueto the fact that they are only activethree months of the year, usually Aprilthrough July. During these monthsmost of the time above ground isspent feeding or sunbathing. Marmotsare herbivores and they eat a widevariety of plants, but they especiallylike dandelions, clovers, and seeds.

Marmots can be found living in colo-nies or as paired animals. The typicalcolony situation involves a haremconsisting of one adult male, severaladult females and their offspring. Thesingly paired social groups are usuallyfound in sites where the habitat limitsthe amount of burrows which can bebuilt. Here one finds burrows inhab-ited by a single marmot, a pair, or afemale and her young.

The recent discoveries of marmotcolonies in natural habitat lead us tobelieve that the small population sizeof the Baker Creek marmot colony islikely due to the use of an atypicalhabitat. The main reason for this un-usual habitat location is most likelydue to the pinyon-juniper invasionwhich has greatly reduced their habi-tat. In studies it has been found thatsmall marmot populations are morelikely to be extirpated. Resourcemanagement is trying to avoid this byincreasing the habitat potential nearBaker Creek by thinning some of thepinyon/juniper near the sagebrushareas.

Please report any marmotsightings outside of Baker Creekto resource management.

New Marmot Colonies(continued from page 1)

By Matthew Reece

The cave crew is going to be up athigh elevation most of the summer.We are busy exploring and mappingthe alpine caves of the park. In thepark, any cave with an entrance at9000 feet or higher is consideredalpine; fifteen of the park’s 43 cavesfit this description, including thedeepest cave in Nevada, as well asthe cave with the highest elevationentrance in the state. In addition tomapping the known caves above9000 feet, the crew will be lookingfor new caves in the southern part ofthe park. This area of the park is

remote and very rugged, and has notpreviously been systematicallychecked for caves.

The majority of the park’s alpinecaves are incredibly technical, requir-ing complex, European-style riggingtechniques and special equipment tosafely traverse ropes. The caves, dueto their high elevation, are also quitecold, requiring special clothing de-signed specifically for caving in cold,wet caves.

Check out the fall issue of theMidden for a report of what the cavecrew found during the summer.

Getting out of the Heat

Some caves will require a rappeljust to get to the entrance

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Pygmy rabbits (Brachylagusidahoensis) were petitioned for listingto the US Fish and Wildlife Service in2003. The Nevada Department ofWildlife (NDOW), under the direc-tion of Dr. John Himes, begansearching for pygmy rabbits to deter-mine what their status was in thestate.

Of 643 sites searched in the state, sixwere within the park. A pygmy rabbitwas observed at one site, freshpygmy rabbit burrows and pelletswere observed at two sites, oldpygmy rabbit pellets were observedat one site, and no pygmy rabbits orsign was observed at two sites.

The pygmy rabbit is found throughoutthe Great Basin desert and into someadjacent areas. They are usually as-sociated with tall stands of old growthbig sagebrush (Artemesiatridentata) and thus, within the park,are most likely to be encountered inthe lower elevations, from about4,500 ft to 7,000 ft. They have a very

distinctive alarm call, which may helpthem communicate with their neigh-bors in the dense sage. Predatorsinclude weasels, coyote, red fox,bobcat, and great horned owl.

Pygmy rabbits are shy and active atnight. They dig their own burrows,and usually do not move more than 30yards away from their burrow. Theyare the smallest member of the genusBrachylagus, with an average length of11.5 inches. They look a great deallike cottontail rabbits, but have nowhite tail.

The findings from the inventory indi-cate that pygmy rabbits are not inimminent danger of being endangered.However, the encroachment of pinyonand juniper into the valley bottomscould pose a potential long-termthreat to pygmy rabbits due to thegradual loss of suitable habitat. Thus,projects aimed at lessening the extentof pinyon-juniper encroachmentshould be considered and conductedwhere appropriate.

Pygmy Rabbits Found in Park

Pygmy rabbit

InterestingWebsites Related tothe Park

Butterflies of Nevadahttp://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/nv/toc.htm

Moths of White Pine Countyhttp://www.npwrc.usgs.gov/resource/distr/lepid/moths/chklist/states/counties/nv_33.htm

Great Basin Wildflowershttp://www.suu.edu/faculty/mar-tin/Provinces/greatbasin/basinflowers.htm

Natural Resources ConservationService Plants Databasehttp://plants.usda.gov/

Great Basin Bird Observatoryhttp://www.gbbo.org

Pygmy rabbit burrow

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Lehman Creek contains a USGSwater stage recorder about ½ mileinside the park boundary at 6730 ft.This water stage recorder measuresthe pressure of water over a trans-ducer (the depth of water, or gageheight) every 15 minutes, and thensends this data every four hours viasatellite to the Nevada District Office.The stream flow (discharge) is calcu-lated from this depth of water. Oncea month a USGS technician visits thegage to check it and to conduct astreamflow measurement. This dis-charge measurement is then corre-lated with the gage height reading,and over time the USGS has devel-oped a rating curve, so that for eachdepth of water they know how muchwater is flowing in the stream. Once ayear the USGS analyzes all the datafrom the stream gage and corrects itbased on the actual discharge mea-surements. Until the data has beenanalyzed, it is considered to be provi-

sional, which means that it maycontain errors.

Graphs of both the discharge andgage height are provided on thewebsite, along with additional infor-mation about past discharge. TheLehman gage has been in operationfrom December 1947 to Septem-ber 1955, October 1992 to Sep-tember 1997, and July 2002 tocurrent year. Of these years, June1992 had the highest monthly aver-age discharge, with 19.2 cubic feetper second (cfs). January 1954 hadthe lowest month average dischargeof 0.54 cfs. Looking at dailystreamflow statistics, June 15th onaverage has the most discharge ofthe year, while February 19th hasthe least.

This year’s spring runoff has beenbelow average. The graph belowshows this year’s runoff as the dark

line, with small triangles indicatingthe median daily streamflow basedon 14 years of record. Many yearshave one peak day for runoff, butthis year the runoff has been morelevel, with small variations based onchanging temperatures. The peakon June 17th was caused by the rainthat day, with 0.67 inches falling atthe visitor center. It will be interest-ing to see how the rest of 2004compares with the average—per-haps since the spring runoff was notas large, the water will continueflowing in the creeks more steadilythroughout the summer.

You can see the current gage heightand discharge and past stream in-formation at the following website:http://waterdata.usgs.gov/nv/nwis/Select Real-time data and click onthe map to select the gage.

Spring Runoff Below Average in 2004

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Researchers Jean Krejca and StevenTaylor were hired by the park to con-duct biological inventories in eightpark caves. The focus was ontroglobitic species (those found deepin caves and that complete their lifecycle within the cave), particularlymacroinvertebrates. A variety of tech-niques were used such as nets, pit-falls, and hand collecting.

Previous studies had found the cavepseduoscorpion (Microcreagrisgrandis)in Lehman Cave, the ModelCave Harvestman (Cyptobunusungulatus ungulatus)in Model Cave,with another species of harvestman(Sclerobunus rubustus) found inthree park caves.

This study found the pseudoscorpionand harvestmen in additional caves,along with spiders, centipedes,springtails, beetles, darkling beetles,flies, ants, snails, wolf spiders, fungusgnats, worms, stoneflies, millipedes,true bugs, fleas, book and bark lice,and crane flies. The researchers alsofound some probable new species,

including a cave adapted millipede, aglobular springtail, and possibly otherspringtails and mites.

Most of these species, found deep inthe caves, rely on the guano fromtrogloxenes (animals that use caves forpart of the time, such as bats andmice) and from leaf litter debriswashed in from entrances. Fungus and

Researchers Find New Species in Park Caves

bacteria then start breaking down theguano and leaf litter, and are in turneaten by the larger macro-inverte-brates. The researchers also ob-served pseudoscorpions eating fliesin the cave.

This study provided a baseline ofmacroinvertebrate populations ineight park caves. Future researchmay include surveys in other parkcaves, studying pack rats to see ifthey are contributing to the food baseof macroinvertebrates, studying thefood chain and how it is maintained,and how surface events, such asfires, affect the subsurface.

All photos courtesy of Jean Krejcaand Steve Taylor.

Millipede

Wolf spider

Electron scanning microscope photo of a pseudoscorpion

E X P E R I E N C E Y O U R A M E R I C A

The Midden is the Resource Man-agement newsletter for Great BasinNational Park.

A spring/summer and fall/winterissue are printed each year. TheMidden is also available on thePark’s website at www.nps.gov/grba.

We welcome submissions of articlesor drawings relating to natural andcultural resource management and re-search in the park. They can be sent to:Resource Management,Great Basin National Park,Baker, NV 89311Or call us at: (775) 234-7331

SuperintendentTom Leatherman

Chief of Resource ManagementTod Williams

Editor & LayoutGretchen Schenk

6 The Midden

National Park ServiceU.S. Department of the Interior

Great Basin National Park100 Great Basin National ParkBaker, NV 89311

Upcoming Events:

July 8, 7 PM Snakes and Amphibians of Great Basin. Great Ba-sin Association (GBA) Program, contact 234-7270 for more info.July 17 & 18 Write the Wild. Campout and get inspiration towrite about the wilds around you. GBA Program, contact 234-7270 for more info.Sept 2, 7 PM Snakes and Amphibians of Great Basin GBA Program, contact234-7270 for more info.Sept 7 Star Night View the outstanding night sky through massive telescopesin Great Basin’s clean air! GBA Program, contact 234-7270 for more info.Sept 18 Osceola Out and Back. Hike 3 miles along Osceola trail and cookout.$10 donation. GBA Program, contact 234-7270 for more info.Sept 19 Star Night View the outstanding night sky through massive telescopesin Great Basin’s clean air! GBA Program, contact 234-7270 for more info.Sept 20 Rural Architecture Slide presentation examining how architecturalstyles, building materials, and ingenuity help rural people survive in Nevada’sharsh environment. GBA Program, contact 234-7270 for more info.

Throughout the Year, Great Basin National Park Volunteer opportunities withresource management are available to help locate springs, conduct animal sur-veys, reclaim disturbed lands, and work on other projects. Contact us at 234-7331.