fisher paper#2

Taylor Luneau 5/10/12

Utilizing Non-Invasive sampling methods in documenting the distribution and behavior of Martes Pennanti

Abstract Tracking and photographic stations offer a non-invasive sampling method when studying mammals with large home ranges like Fisher (Martes Pennanti). Fisher, found

most commonly in lowland mixed coniferous forests, are characterized by their similarity to the weasel family, but with a stockier, elongated muzzle and rounded ears fixed close

to a triangular head. Their preferred solidarity and large home ranges make the Fisher an elusive and difficult animal to study. However tracking can be implemented as a means to understand their large home ranges and identify significant features in their

microhabitats. Once sign has dictated a high activity level of fisher in one confined area, photographic stations can be used to document fisher behavior and characteristics. The

use of this kind of sampling method avoids any chance of injuring or tampering with the natural behavior of the animal, thereby limiting ethical concerns and scientific bias. During the period of February 12th to April 12th, 2012 two locations were observed for

fisher behavior. Both sites were identified by Susan Morse at her research facility in Jericho, VT where she currently maintains the longest running track and sign survey in

the country. Once cameras were strategically set in view of these “hot spots” they were checked once a week for data collection. Fifty-eight pictures were taken during the two month period with a total of twelve separate visits by fisher, five occurring at site one and

seven occurring at site two. All of the pictures revealed behavior consistent with scent marking and was appropriate for the time considering March has been noted as the most

active time in the fisher breeding season. The non-invasive techniques used were successful in collecting non-biased information about the presence, characteristics and behavior of fisher within our transect. The continued use of non-invasive sampling

methods is imperative in the conservation of the mammalia species and furthermore detrimental to the preservation of genetic and ecological diversity in the Northern woods

of New England. Introduction

Many species of the genus Martes can be found north of 35 degrees latitude,

where snowfall envelops their natural habitat for a large portion of the year (Proulx,

2006). When considering possible techniques in documenting the elusive mammal, one

must strongly consider the use of tracking in combination with photographic stations

positioned strategically at well-traveled corridors. Scientists have employed the method

of tracking in the past as a means to document the presence of fisher (Martes pennanti) in

diverse habitats as well as ascertain specific behaviors and monitor population trends

(Proulx, 2006). The presence of snow provides a well-defined substrate for the fisher to

leave its trail behind and allows trackers a suitable means in documenting the fisher’s

place in space and time. Snow is not the only substrate suitable for this job; in fact sand

2 Taylor Luneau

and mud can be employed in the absence of snow but are far less abundant than the thick

white blanket provided by northern winters.

Development of new, more technological methods has discouraged many

scientists from implementing tracking as a means for mammal documentation (Beauvais,

1999). For instance with the dawn of radio-telemetry, many scientists have preferred the

use of radio collars when studying animal movements and behavior (Proulx, 2006).

However similar to live trapping, the animal must be restrained, anaesthetized and

otherwise marked in order to study and record the animal meticulously. Other than the

many ethical concerns which accompany this invasive practice, the simple disruption of

the animals natural behavior may present scientific challenges as well. The use of baiting

at a live trap, for instance may cause an animal to stray away from its natural habitat to

investigate the unknown food source (Proulx, 2006). This invasive method creates a bias

when assessing the animal’s natural movement across a particular landscape through the

alteration of its normal behavior and trajectory.

We must therefore consider the benefits gained through using a non-invasive

sampling method such as tracking. Not only does the technique afford a more specific

measurement of an animal’s movement through microhabitats, (in comparison to radio

collars) but a fine scale analysis of resource use, foraging behavior and scent marking.

Furthermore, tracking and photographic stations, unlike radio-collars or live traps, offer a

non-invasive method to observing mammals without otherwise harming the animal or

altering its behavior (Pulliainen, 1982).

Tracking and photographic stations can offer valuable information about Martes

and how they utilize their winter habitats. Male fisher home ranges average around 8^2

miles while females average closer to 6^2 miles (Douglas and Strickland, 1987).

Tracking, while time intensive, provides a finer analysis of the fisher behavior and

minimizes their large range distribution to a series of “hot spots” where photographic

stations can be implemented. Fishers are usually found in mixed forests with continuous

overhead cover (Powell, 1993). Specifically, in the Northeast of the United States fisher

have demonstrated a strong selection towards lowland coniferous forests containing

spruce, fir, white cedar and some hardwood forests (Powell, 1993). Their choice in


habitat is most likely a result of their preference in food availability and denning sites

(Douglas and Strickland, 1987).

As a member of the weasel family, the medium sized mammal is characterized by

its stocky build, elongated muzzle and rounded ears set close to a rather triangular head

(Powell, 1993). The fur of the fisher is highly dependent on the individual as well as the

season and sex of the mammal (Powell, 1993). During the winter months, when this

study was undertaken, the fisher has primarily a dense, black coat with lighter colored

hairs around the face and shoulders (Powell, 1993). There is also high sexual dimorphism

within the species as males typically have a larger body size and more pronounced

physical weight than females (Powell, 1993). This dimorphism may allow the two sexes

to easily coexist within the same habitat through sharing available resources that are of

great demand. For instance as carnivores, Fisher prey primarily on snowshoe hare,

squirrels mice and porcupines but will occasionally forage on berries as well (Powell,

1993). Dimorphism therefore aids in leveling demand between sexes for restricted prey

within their selected home ranges and affords plenty of denning sites for both males and

females.

Based solely on our understanding of Fisher preference in home ranges and food

demands, we can narrow our search for fisher tracks to lowland mixed forests. With this

information we can utilize tracking to identify the presence of Fisher and then further

investigate to find areas of high traffic such as denning sites, scent marking stations or

food sources. Once our investigation has yielded a potential “hot spot” of activity, we can

then proceed to using photographic stations to obtain a greater understanding of Fisher

behavior in their natural habitats. This process provides a non-invasive, un-biased means

to the examination of Fisher populations and behavior and thus provides us with a less

stressful alternative to other techniques. If this traditional technique is used in accordance

with highly stringent data collection and analysis, a more proficient means to assessment

of the ecological needs of Fisher can be determined.

Methods

Establishment of transect

4 Taylor Luneau

Our intent in documenting Fisher behavior, led us to choosing transects in low

land mixed coniferous forests. These transects were located at Wolf Run, a research

facility operated by Susan Morse, where she has collected data on mammal species,

varying from black bear to bobcat and fisher, for more than 36 years; making it the

longest running track and sign survey in the U.S. (Keeping Track). Susan had recognized

these particular transects as ones that would provide habitat connectivity and wholeness

as well as noted keen marking behaviors and track identifications. Two particular “hot

spots” were chosen as valuable areas for photographic stations. The valuableness of these

spots were due to the high density of fisher tracks as well as the high likelihood of being

scent-marking stations.

Tracking

When detecting Fisher track and sign there are clear characteristics which one

must take in to account during the identification process. Firstly we must recognize the

matter by which Fisher move through out their habitat. The movement of Fisher is quite

typical to the weasel family (Powell, 1993). Characterized by a bounding gait, the

forelimbs, moving together with one slightly ahead of the other, leave the ground just

prior to the landing of the hind feet. The track of the hind feet, therefore overwrites that

left by the fore feet (Morse, 2011). In good substrate we will notice four slightly

asymmetrical toes with the presence of a fifth off set toe on the medial side of the print

(Morse, 2011). Behind these toe impressions will be a knobby, interconnected upside

down “C” that corresponds to the palm pad of the Fisher (Morse, 2011). One may also

note a small round impression behind the palm pad, this impression is caused by the

carpal pad and can only be found on the fore foot (Morse, 2011).


Figure 1. Depicts the tracks left by Martes pennanti. l.f. stands for left fore while l.h. stands for left hind (Taylor, Raphael, 1988). Fore feet prints average around 4in long by 3 and 1/2in. wide; hind feet prints average roughly 3in long by 3in. wide (Morse, 2004). The length between bounds averages between 12-50in (Morse, 2004).

While the tracks of fisher will most often be found in a two by two pattern, other

configurations are quite probable. Track sets of three or even four may exist as the Fisher

walks or runs through its environment (Morse, 2011). It should also be noted that

backtracking should always be used when investigating the distance and directional

changes of any mammal tracks. If forward tracking is used shortly after the tracks are

laid, an animal could be pushed to change their behavior, direction or habitat in response

to the investigators pressure (Proulx, 2006).

Locating possible scent marking stations

Tracks identified as Fisher may lead to highly disturbed areas noted by Morse as

“shuffle marks” (Morse, 2010). These shuffle marks correspond to flattened areas in the

snow where fisher have rubbed their bodies or possibley rolled around (Morse, 2010).

The use of urine or feces is also common in scent marking behavior and should be looked

for when encountering possible scent stations (Morse, 2010). Many fisher scent stations

6 Taylor Luneau

can be found on elevated surfaces such as rotten logs, sticks or rocks (Morse, 2010). The

absorbent nature of rotten logs provides a good natural substrate for obtaining and

holding scent for a long time and should therefore be investigated intently (Morse, 2010).

Belly hairs as well as “tar-like” secretions from Fisher perianal glands may be

distinguished as well at these stations and will provide further evidence to the presence of

Fisher (Morse, 2010).

Documentation and use of photographic stations

Once possible scent stations were acknowledged the use of Reconyx game

cameras were employed to document the area. Reconyx hyperfire game cameras were

mounted on surrounding trees located in clear vision of probable scent marking stations

at Wolf Run. Documentation of the sites of interest occurred from February 12th, 2012 to

April 12th, 2012. Cameras were checked roughly once a week in order to record

visitations of mammals and preserve pictures taken. A computer was taken in to the field

when checking the cameras and after removing the memory card of the cameras, content

was observed to note changes in visitation and use. At the culmination of the experiment

only pictures of Fisher were used in collective data sets and interpreted for the mammals

behavior.

Results

Fifty-eight pictures were taken during the two-month period lasting from February 12th to

April 12th 2012. The photos analyzed are a cumulative set between the two sites of

interest and had a total of twelve separate visits, five occurring at site 1 and seven

occurring at site 2.


Figure 1. Represents the percent of total pictures taken on each visitation. This illustrates the varying activity levels of Fisher within our transect during our two month study period. Note that two visitations occurred during March 5th but have been grouped into one sample.

0

0.05

0.1

0.15

0.2

0.25

0.3

12

-Fe

b1

4-F

eb

16

-Fe

b1

8-F

eb

20

-Fe

b2

2-F

eb

24

-Fe

b2

6-F

eb

28

-Fe

b1

-Mar

3-M

ar5

-Mar

7-M

ar9

-Mar

11

-Ma

r1

3-M

ar

15

-Ma

r1

7-M

ar

19

-Ma

r2

1-M

ar

23

-Ma

r2

5-M

ar

27

-Ma

r2

9-M

ar

31

-Ma

r2

-Ap

r4

-Ap

r6

-Ap

r8

-Ap

r1

0-A

pr

12

-Ap

r

Pe

rce

nt

of

tota

l p

ictu

res

tak

en

Date of Visitations

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

12

am-1

am

1a

m-2

am

2a

m-3

am

3a

m-4

am

4a

m-5

am

5a

m-6

am

6a

m-7

am

7a

m-8

am

8a

m-9

am

9a

m-1

0a

m

10

am-1

1am

11

am-1

2p

m

12

pm

-1p

m

1p

m-2

pm

2p

m-3

pm

3p

m-4

pm

4p

m-5

pm

5p

m-6

pm

6p

m-7

pm

7p

m-8

pm

8p

m-9

pm

9p

m-1

0p

m

10

pm

-11

pm

11

pm

-12

pm

Pe

rce

nt

of

tota

l v

isit

ati

on

s

Time of day

8 Taylor Luneau

Figure 2. Depicts the percentage of visitations at varying time intervals through out the day. Visitations that occurred within the same one-hour time block have been grouped for that specific time.

© Keeping Track, Susan C. Morse

Figure 3. One of three photos taken in a visitation of a fisher at site two. The fisher continued to drag it’s groin and belly on the stump in the following two photos.



Figure 4. Fisher here is shown dragging groin and belly along a stick that is attached to a fallen log at site one. The top of the stick can be seen bellow the left shoulder. This photo is one of five in a visitation.


Figure 5. Fisher clutching and pressing nose firmly against stick at site one. This photo is one of six in a visitation. Note that two other photos during this specific visitation showed the fisher pressing it’s nose against other areas of the stick.

10 Taylor Luneau


Figure 6. Fisher holding and pressing nose against stick at site one. This photo is one of fifteen during a specific visitation.


Figure 7. Fisher shown dragging head, chin, face, belly and groin along stick at site one. This photo is one of fifteen taken during the same visitation and was shot only seven seconds after that of Figure 6.

During the two-month study period fisher were most active between March 5th

and March 15th. As seen in Figure 1, no visitations occurred until February 20th when at

site two, 15% of the total pictures taken, were shot. This was the first documented fisher

activity occurring at either site. After detecting only one short visitation on February 27 th,

it was not until March 5th when activity levels began to substantially increase. Fishers

were documented visiting site 1 at 12:15am on March 5th and then again at 6:54 am.

Figure 1 shows that 19% of the photos taken through out the study occurred during the

day of March 5th. However, the most photos taken were shot on March 8th, which even

though occurred in only one visitation from one fisher, made up over 25% of the total

pictures taken. Also in contrast to February, which averaged 7 days between recorded

visitations over a 17 day period; March averaged only 2.25 days between visitations

during the first 17 days of the month.


Fisher not only visited the sites at varying intensities through out the month but

also at varying times. Referring to Figure 2 we note that fisher visited the sites most often

between the hours of 6 and 7am. Visitations during this period of the day account for

more than 33% of the total visitations recorded. Sixteen percent of the total visitations,

the second most, occurred between the hours of 6 and 7pm. Also note worthy, was the

varying temperature that unexpectedly fluctuated through out the two-month span.

Temperatures averaged around 27 degrees Fahrenheit during each visitation however had

a low of 3 degrees Fahrenheit on March 5th and a high of 45 degrees on March 8th.

As noted by Powell, fisher are characterized by their stocky and elongated build,

triangular head, dark fur and small rounded ears. From this we can quickly infer that the

pictures presented in Figures 3-7 are all of Fisher (Martes pennanti). What seems more

difficult however, is discerning differences between male and female sexes. As discussed

previously, males typically have a much larger body size and pronounced physical weight

than females (Powell, 1999). However Douglas and Strickland also noted significant

differences in both length and weight of juveniles in comparison to the much larger adults

(Douglas and Strickland, 1987). Males, who are generally spermatic by twelve months,

undergo an enlarging of the Testes during the winter months and reach their largest in

size by March (Douglas and Strickland, 1987). We can see in figure three what appear to

be enlarged testicles of the male fisher placed directly atop of the stump that it is perched

on. We should also note the large size of it’s tail and hind end which largely resemble

that of the size of the fisher in Figure 4. The size of the tail and hind end of this animal

largely resembles that of the male in Figure 3.

While a striking resemblance exists between the Fisher portrayed in Figures 3 and

4, there appears to be a strong difference between those and Figure 5. Here we note a

shorter and less wide tail, and more importantly a much slimmer body. The fisher in

Figure 5 is discernable smaller than that of 3 and 4 and should therefore be referred to as

another fisher entirely. The sex of this fisher is difficult to determine due to lack of

critical evidence, however based on the characteristics provided we can assume that the

Fisher in Figure 5 is either an adult female or a juvenile of either sex.

The Fisher seen in Figure 6, which strongly resembles that of Figure 4, has taken

a very similar pose to that of Figure 5. The animal in Figure 6 clearly has a much larger

12 Taylor Luneau

body, head and tail size when compared to that of figure 5. This is further evidence

leading us to believe that the fisher in Figure 5 is probably not an adult male. We can also

see in Figure 7, a fisher that is laying out across the stick in the middle of the frame. This

behavior, or a similar one, was observed in each visitation depicted in Figures 4-7. In

each visit, the face, belly or groin was rubbed on the stick protruding from the fallen log.

This behavior was documented in several pictures on each visitation. Furthermore we

note the behavior seen in Figure 5 and 6, and observe the fisher pressing its nose firmly

against the same stick that had been rubbed against. This behavior was also observed in

each of the visitation depicted above.

Discussion

The utilization of non-invasive sampling methods has been shown by this study to

provide not only verifiable documentation of the presence of Martes pennanti, but also

defining characteristics as well as defining differences in behavior. The traditional

method of tracking was employed in discovering fisher sign and identifying important

features in the fisher’s microhabitats. After determining these important features, the

implementation of photographic stations further expanded our understanding of fisher

characteristics and behavior. Not only did this non-invasive technique avoid harming the

animals in any way, but it also documented the animals in a non-biased way by

maintaining the natural behavior and trajectories of each fisher.

Due to the clear likelihood of the Fisher in Figure 3 being a male, we can suggest

that the fisher seen in Figures 3, 6 and 7 are also male due to the large similarities

between the animals. We can also suggest that the believed male fishers are all one and

the same. Due to the larger energy requirements of males, their home ranges tend to be

disproportionately larger than those of females (Powell, 1999). For this reason home

ranges of the same sex tend not to overlap (Powell, 1999). However, home ranges of

opposite sexes tend to overlap extensively which Powell termed “intrasexual

territoriality” (Powell, 1999). The animal’s territory is comprised of resources, such as

food and mates, and will often be prioritized by only one male (Powell, 1999). While

Powell asserts that the use of scent marking can deter male-male aggressive interactions

by claiming territory ownership, Douglas and Strickland discovered that evidence of


intraspecific fighting existed and occurred 37% more often between adult males than

adult females (Douglas and Strickland, 1987). It would therefore make sense that the

male fisher observed in this area would be the only male documented due to our transect

being far smaller in size than the predicted home ranges necessary for more than one

male fisher.

Based on the evidence provided that limits the possibility of more than one male

in a specific territory, we are led to believe that the fisher appearing in Figure 5 is a

female. The slender build of the animal and the clear differences in body shape when

compared to that of Figures 3, 4, 6 and 7, suggest that the fisher in Figure 5 is actually a

different animal. However if this is possible, why do the two animals share such similar

behaviors? Both appeared very interested in the sticks at site 1 and 2 and for some reason

rubbed up against them during each visitation. Furthermore, both of the fisher pressed

their noses against the sticks, a behavior which is most likely in accordance with

smelling, multiple times during each visitation.

What is believed to be occurring is the process of communication through scent

marking. Powell noted the likelihood of fisher during the winter to approach and drag

their bellies across stumps protruding from the snow (Powell, 1999). This behavior,

which is also clearly seen in Figures 3-7, is noted as scent marking by Powell. It is

presumed that the abdominal, plantar and perianal glands located on the animal, secrete a

“tarry” like substance which provides valuable information to other fishers in the area

(Feldhamer et. al, 1984). This includes information about the sex of the animal as well as

the sexual activity, maturity and perhaps territorial behavior (Powell, 1999). This

information of sexual activity, aimed towards mates, reaches it’s most abundant during

the breeding months of late February through mid April (Coulter, 1966). During mid

March, the increase in fisher activity appears to be correlated to the breeding season, and

as Powell notes, is highly dependent on elevated levels of male testosterone (Powell,

1999). The believed scent marking in Figures 3-7 are in clear agreement with the fisher

breeding season and behavior as well as the high sexual activity of male fisher during the

month of March.

The information provided by this study has given a clear look into the scent

marking behavior of Martes pennanti and determined our transects as significant

14 Taylor Luneau

breeding zones for the animal. With this in mind, we can assess the habitat surrounding

our transects to obtain a greater understanding of the ecological necessities for a specific

habitat to support a breeding fisher population. For instance, we may find that the hare

population within the surrounding area is optimal in supporting the caloric demands of

multiple fisher. We may also determine that there is an abundance of hemlock in the area

where fisher will cache their food; or perhaps a healthy abundance of yellow-birch where

fisher will nest in it’s cavities. Further studies should be conducted to obtain a more in

depth understanding of the fisher behavior as well as scent marking and mating rituals.

However if anything, tracking has provided us the simple understanding that the fisher

population in our study area is healthy enough to participate in the breeding season. From

this we can draw conclusions to why this habitat is able to successfully support this

population.

The use of tracking and photographic stations offers a powerful alternative to

newer sampling methods. The non-invasive means by which the method is carried out

and the unbiased results that it produces are un-paralleled. With Vermont, and much of

the rest of New England and New York, providing necessary habitat for fisher and other

mammals, it is imperative that we maintain habitat connectivity to support the health and

sustained growth of the mammals in our environment. Wide ranging species like the

fisher must be uninhibited when moving from region to region in search of resources like

food, denning sites and mates. We must continue to study these amazing animals to

obtain a greater understanding of their biological demands as a means to preserve genetic

and ecological diversity. The use of tracking and photographic stations as sampling

methods, are therefore necessary tools in the conservation and diversity of the biological

communities that surround us.

Acknowledgements

I would like to thank Susan Morse for sharing her tracking expertise and mammalia knowledge with me. I am extremely grateful to Sue and Keeping Track for allowing me to study the fisher population on their land at Wolf Run in Jericho, VT and for also providing me with Reconyx game cameras to document fisher behavior. Susan has taught me so much in the woods and I owe her a great debt. Furthermore I would like to send a special thank you to Valerie Banschbach for her guidance and assistance through out the duration of this project. My opportunity to


study with Keeping Track would not have existed had it not been for Valerie, and for that I thank you so much.

16 Taylor Luneau

Works Cited

1) Beauvais, G. P., and S. W. Buskirk. 1999. An improved estimate of trail detectability

for snow-trail surveys. Wildlife Society Bulletin 27: 32-38.

2) Coulter, M. W. 1966. Ecology and management of fishers in Maine. Ph. D. thesis, St. Univ. Coll. Forest., Syracuse University, Syracuse, N.Y.

3) Douglas, C., and M. Strickland. "Fisher." Wild Furbearer management and

Conservation in North America. Ed. Novak. 1. Ontario, Canada: Ontario Trappers Association, 1987. 510-530.

4) Feldhamer, G., B. Carlyle, and J. Chapman. "Fisher and Marten." Wild Mammals of North America/Biology, Management, and Conservation. 2nd. Baltimore and

London: John Hopkins University Press, 1984. 5) Martes in Carnivore Communities, pages 211-224M. Santos-Reis, J. D. S. Birks, E.

C. O’Doherty, and G. Proulx, editors, 2006 Alpha Wildlife Publications, Sherwood Park, Alberta, Canada

6) Morse, Susan. "Fisher Forays." Northern Woodlands. (2011)

7) Morse, Susan. "Getting on the stick." Northern Woodlands. (2010)

8) Morse, Susan. Northern Forest Mammal Tracker. 1. Discover Wonder, 2004.

9) Proulx, Gilbert, and Erin O'Doherty. "Snow-Tracking to determine Martes winter distribution and habitat use." Alpha Wildlife Publications. (2006): 211-224.

10) Pulliainen, E. 1981. Winter habitat selection, home range, and movements of the pine

marten (Martes martes) in a Finnish Lapland Forest. Pages 1068-1087 in J. A.

Chapman and D. Pursley, editors. Proceedings Worldwide Furbearer Conference. Frostburg, Maryland, USA.

11) Taylor, Cathy, and Martin Raphael. "IDENTIFICATION OF MAMMAL TRACKS FROM SOOTED TRACK STATIONS IN THE PACIFIC NORTHWEST." CALIFORNIA FISH AND GAME. N.p., 4/15, 1988. Web. 10 May 2012.

<http://www.fs.fed.us/psw/publications/4251/taylor1.pdf>.

fisher paper#2

Documents