Tracks, scat, slides, and porcupine butts

It seems like the weather has kept me cooped up indoors all winter.  Over the past two weeks, local schools have been in session for a grand total of two days out of ten; on one of the days that they actually had school there was a weather delay.  I have already had to cancel or reschedule thirty-five school programs since the second week of January.  So imagine my excitement to have nice weather on Saturday (09 February) for a planned animal signs hike at the Chippewa Watershed Conservancy's Hall's Lake Natural Area.  Sunny weather and a couple of inches of fresh snow!  What more could we ask for!

Hall's Lake is located on the far west side of Isabella County.  The three main preserves (Kabana, Neely, and Schaftenaar) that make up Hall's Lake Natural Area encompass 155 acres of woodland and wetland protect nearly one half of the shoreline of Hall's Lake from development.  This land serves as habitat for a wide variety of animal species.  I was fairly confident that we could find tracks (or other sign) for several common species such as white-tailed deer, coyote, squirrels, mice, and voles.  All of these tracks were present and easy to find.  We also discovered a set of tracks belonging to either a small American mink or a large long-tailed weasel - there is a little bit of overlap in track size so I was not 100% confident in assigning the tracks to one species.

The best tracks of the day were a surprise to me - they probably shouldn't be, but I rarely see them.  We found tracks from both the North American river otter (Lontra canadensis) and bobcat (Lynx rufus) along the shore of Hall's Lake.  At first I had some difficulty identifying the tracks because both animals had traveled along the same path and their prints sometimes overlapped.  Also, snow had drifted into many of the tracks making it hard to see their features.  Finally, the tracks diverged in a sheltered area and I was able to see enough identifying features to make a positive identification.

This is a print from an otter - the important thing to note is that it has five widely spread toes.

Here is a set of all four otter feet as it bounded along in the snow - the otter was traveling from right to left in the picture.  We did notice several tail drags along this path, but I didn't photograph any of them.

Here is one of the bobcat tracks.  Note how this track has only four toes.  We also found several coyote tracks.  It's easy to tell the bobcat and coyote tracks apart; look for toenails.  If you see toenails the print belongs to a coyote - cats (such as bobcats) usually have their claws retracted and the nails rarely show up in their footprints.

In this picture you can easily see the spacing of the bobcat's tracks.  At one point I couldn't decide if some of the tracks belonged to a small bobcat or a large domestic cat.  The prints were in rough terrain and the stride was quite short, but here in the open on this trail the animal opened ups its gait.

We eventually discovered the tracks of not one, but two bobcats on site.  The two could be told apart  by the different size of their tracks.  Like most wild cat species, bobcats will not usually share a territory with another animal of the same sex.  Males normally have larger territories than females.  Either Hall's Lake Natural Area is on the boundary of two territories of same-sex animals or two animals of the opposite sex have territories that overlap.

Bobcats often mark their territory by urinating or defecating in places where other Bobcats (and other predators such as coyote or red fox) will notice it.  Just like a domestic cat, this Bobcat kicked up the snow after leaving its mark.  Fox and coyote (and my dog) exhibit the same kind of behavior.

The bobcat scent station was only the second coolest thing we found during the hike.  My favorite can be seen in the two pictures below - an otter slide!  With short legs and a body shaped like a sausage, sometimes the easiest way for an otter to move (especially downhill) is to slide on its belly.

Checking out the otter slide

Slide!

There was one more stop we had to make.  Hall's Lake Natural Area has a well-known porcupine den tree.  In all the times I've ever been to Hall's Lake, I've never seen more of the porcupine than its rear end hanging out of a hole in the tree.  Last year during a hike at Hall's lake we found a second porcupine high up in an Eastern White Pine, but no such luck today.  So on to the den tree...

Normally, when I see the porcupine it's tucked up in the top of that hole.

Believe it or not, this is actually the best view that I have ever had of this porcupine.  This individual porcupine seems to be almost completely nocturnal.  It comes out of this den tree at night and travels to a nearby stand of pine trees where it feed before returning to the den to sleep away the day.

All in all, I'd declare this a very successful animal sign hike, filled with tracks, scat, slides, and porcupine butts! 

Bobcat Population Tracking

Yesterday I got to ride along in a truck with my friend and colleague Heather Shaw for a few hours.  Heather is the wildlife biologist for the Saginaw Chippewa Indian Tribe and she is currently working on a survey of Bobcat (Lynx rufus) populations in Isabella County.  A graduate of Central Michigan University, Heather has previously worked as a wildlife technician for the the Wyoming Department of Fish and Game and as a biologist for Ducks Unlimited in both Michigan and North Dakota.  In addition to working for the Saginaw Chippewa Tribe, she is also completing work on her masters thesis at CMU (expected defense coming up this fall).

Heather Shaw, wildlife biologist for the Saginaw Chippewa Indian Tribe, fills out a bobcat survey data sheet

Why monitor bobcat populations?

Bobcats are notoriously secretive and often have widely dispersed territories.  I have seen several road-killed Bobcats, but have never seen a live one in the wild.  Even wildlife biologists rarely see them except by chance.  It is very difficult to know exactly how many bobcat can be found living in a given area.

So how do you monitor a population like that?

Heather is using a series of scent stations situated along roadside transects in likely bobcat habitat.  What this means, is that along a selected path (a transect) she was setting up a bed of sand to record footprints and baiting it with a scent tablet to attract bobcat (and other predators).  When an animal investigated the scent tablet, their footprints would recorded in the sand, enabling Heather to build a picture of the locations where bobcats can be found.
 

This map shows the location of the bobcat survey transects in Isabella County (and penciled in near the corner, the location of an Amish bakery - biologists love baked goods)

The locations of these transects has been chosen by the Michigan Department of Natural Resources (DNR) based on models that predict possible bobcat habitat.  Each transect is three miles long and has a scent station located every 1/3 mile along the transect.  This is the second year that Heather has been conducting this survey in Isabella County - she also has one transect located in Midland County (the next county to the east).

One of ten scent stations located along Rolland Road

Why is this monitoring effort important?

Heather is not the only person setting up these stations and recording data.  Other biologists around the state are recording the same type of information.  This information is used by the Michigan DNR to set seasons and bag limits for bobcat hunting and trapping.  Bobcat hunting and trapping are currently allowed in the Upper Peninsula and northern Lower Peninsula, with Isabella County included in the the hunting/trapping zone.  Isabella County is one of the most southern Michigan counties where bobcat hunting and trapping are allowed.

What did we find?

We followed two of the transects that Heather had set up earlier in the week.  Both of these transects were located in the southwest corner of Isabella County.  The first transect was located on a gravel road that sees very little traffic.  The second transect was located on a relatively busy paved road.  These transects are set up along roadsides so they are easy to check.  In addition, many animals including bobcats will use roads as travel corridors, to these stations were likely to be found by any bobcat traveling through the vicinity.

This station along Gilmore Road had several tracks, but none belonged to a bobcat

Many of the scent stations that we visited were completely undisturbed, but we did find tracks from domestic dogs, house cats, raccoon, coyote, fox (possible), white-tailed deer, and birds.  At a station established where Rolland Road crosses the Pine River, we found a set of bobcat tracks.

This station along Rolland Road finally yielded a bobcat track

At each station, Heather measured and recorded any bobcat tracks and recorded all of the other tracks that we discovered.  Then, if necessary, she "reset" the station by smoothing out the sand and replacing the scent tablet if needed.

Heather photographing a bobcat track

Heather measures a bobcat track

Heather "resets" a scent station by smoothing the surface

This survey is almost done for the year.  In addition to the scent stations, Heather set up several trail cameras along the transects.  Her next step will be to sort through all of the trail cam photos - she expects a lot of car pictures.  I can't wait to see if any bobcats were "captured".

A day with a wildlife biologist

Yesterday I had the opportunity to participate in something really cool.  I got to tag along with Heather Shaw, wildlife biologist for the Saginaw Chippewa Indian Tribe, while she checked on a series of sites designed to identify and monitor Bobcat (Lynx rufus) populations in Isabella County.  A graduate of Central Michigan University, Heather has previously worked as a wildlife technician for the the Wyoming Department of Fish and Game and a biologist for Ducks Unlimited in both Michigan and North Dakota.  In addition to working for the Saginaw Chippewa Tribe, she is also completing work on her masters degree from CMU.

Wildlife biologist Heather Shaw measures and records tracks at a scent station

Like most people, I have never seen a live bobcat in the wild.  Bobcats tend to be secretive, and are often widely dispersed across large territories.

How do you monitor a population like this?

Heather is using a series of scent stations situated along roadside transects in likely bobcat habitat.  What this means, is that along a selected path (a transect) she was setting up a bed of sand to record footprints and baiting it with a scent tablet to attract bobcat (and other predators).  When an animal investigated the scent tablet, their footprints would recorded in the sand, enabling Heather to build a picture of the locations where bobcats can be found.

Scent stations were set up along the edges of local roads - sometimes in built-up areas

 

Other stations were located in more rural areas

Why is this important?

Heather is not the only person setting up these stations and recording data.  Other biologists around the state are recording the same type of information.  This information is used by the Michigan Department of Natural Resources to set seasons and bag limits for bobcat hunting and trapping.  Bobcat hunting and trapping are currently allowed in the Upper Peninsula and northern Lower Peninsula, with Isabella County included in the the hunting/trapping zone.

What did we find?

We followed three transects that had been set up earlier in the week.  Each transect consisted of a number of scent stations spaced 1/3 mile apart.  These transects were set up directly along the sides of roads so they are easy to check.  Animals including bobcats will use roads as travel corridors, so these stations were likely to be exposed to any bobcats traversing the area.

Each station consisted of a smooth bed of sand approximately 2 to 3 feet in diameter.  A fatty acid scent tablet was placed in the center of each station.  These tablets are attract many species of predators and are even investigated by herbivores such as deer.  I could smell the tablets.  Bobcats have a better developed sense of smell than humans so they should definitely be able to smell it.
 

Tracks circling a scent tablet

We ended up finding lots of tracks - domestic dog, house cat, coyote, fox (probable), opossum, raccoon, white-tailed deer, wild turkey.  Some tracks were not distinct enough to positively identify, but yes we did find bobcat tracks at several of the stations.  We found definite bobcat tracks along two of the transects and possible bobcat tracks along the third transect.

A likely bobcat track - this track definitely belongs to a feline and is probably too big for a domestic cat

A clear pair of bobcat tracks - with coyote tracks in the background

 
At each station, Heather would measure and record all possible bobcat tracks as well as recording tracks of other species.  Then she "reset" the site using a board to smooth the sand and replaced the scent tab if needed.  

Heather Shaw resets a scent station  only yards from M-20

This study is wrapping up for the year, but Heather plans to repeat the study next year and hopes to incorporate trail cameras.  Trail cameras will take those probable tracks and turn them into a definite "yes" or "no".  Heather has other possible wildlife study plans