Friday, June 28, 2013

The Beaten Bear, Poor Ol' Slim, and a Size-13 Snapper!

A random conglomeration of stuff from recent happenings during summer field work.  There's been alot of things going on.  There's so much to share that I can't fit it into a blog post in any type of logical order.

We've been running the drift fences surveys since the beginning of May, which has resulted in many excellent captures (one of which is below).

Yet, we also see cool stuff while we are walking out to our fences.  For example, there's an old gnarled tree that overhangs the creek near one of our fences.  Every day there are multiple Northern Watersnakes (Nerodia sipedon) hanging on the branches catching some rays.

Photo by N. Rudolph

They never really appreciate my grabbing them...and the result is usually a bit of drawn blood (as you can see on my hand below).  The bite looks much worse than it is, however.  They are non-venomous, and their teeth feel like nothing more than tiny pin-pricks.
Photo by N. Rudolph

The poor watersnake frequently suffers greatly at the hands of humans.  When the average person sees a snake near the water with a body pattern that is NOT similar to a gartersnake, they often think: "cottonmouth!" or "water moccasin!" and the snake is killed.  There are NO cottonmouths or moccasins in the upper Midwest, unless one inlcudes southern Illinois (and I don't think they do?). 

Amazingly, folks often argue with me about this!  Here are example responses I get to telling them it wasn't a cottonmouth they saw: "Nope, I saw a cottonmouth on that canoe trip.  There's nothing else it could have been." ...or..... "Well, I'm pretty sure that it was a moccasin that swam along the bank next to me while I was fishing.

But, let me re-iterate: the snakes in my hand above are NOT cottonmouths/moccasins!  We do not have said venomous species 'round these parts.

BUT....none of this is even the point of my current post!  So, I'll get on with it....


The Beaten Bear:

Below is an impressive and "battle worn" Black Bear (Ursus americanus) that the wolf researchers captured on one of the camera traps.

Take a look at the lip on the left side of his face (right at the beginning of the clip).  It looks to be torn....and his ears have clearly seen better days.  He must be a wily sort to have avoided the hunters all these years.

I wonder whom he had a run-in with to have acquired all of that damage?  Males compete for breeding rights, and perhaps his
I wonder whom he had a run-in with to have acquired all of that damage?  Males compete for breeding opportunities and perhaps this was from another male Black Bear?  They certainly run afoul of wolves, which may be particularly problematic when wolves have pups in the den. Hunting dogs are another possibility, I suppose.  But all of that damage is to the face and head.  Is this type of damage typical of such encounters?  Could the torn up ears be where identifying ear tags were yanked out?

I love a natural history mystery!

Poor Ol' Slim:

Poor Slim.....the unfortunate Short-tailed Weasel (Mustela erminea) that I found dead on the road not far from my house.  I caught a glimpse of it while my daughter and I were driving home one day....and I thought it looked like a weasel, so we had to turn around so I could pull over and snap a picture (it wasn't in good enough condition to turn into much of a specimen).

Slim is either a juvenile Long-Tailed Weasel (Mustela frenata) or an adult Short-Tailed Weasel (M. erminea), based on the size and the black tip on the tail.  The other weasel in our state...the Least Weasel (M. nivalis) has no black tail tip. 

Adult Long-Tailed Weasels attain average sizes (13-16 inches) and this individual is not that large.  Yet, this could be a juvenile Long-tailed Weasel....which would also make sense, seeing that the Long-Tailed Weasel is more common in the southern part of the state (where I am located) than the Short-tailed.  But the tail on this specimen looks to be particularly short. 


Another good mystery!

Fortunately, the summer hasn't been only negative encounters with weasels.  Below are pictures of a little Least Weasel my students and I captured in a drift fence a few weeks ago (note the lack of black-tip on the tail).  The drift fences are primarily for amphibians and reptiles, but we get just as many small mammals.  In fact, the hidden secret of this herpetological technique: it's probably just as effective and less work day-in and day-out for small mammals as Sherman Traps.  Although the fence takes alot of effort to install initially, there isn't the hassle of setting and re-baiting traps all the time.  Plus, we get many intectivores (Shrews) and the occassional weasel, which Sherman Traps aren't effective at catching.

I imagine these little carnivores are attracted to the fence due to the smell of vole, which we catch many of.  According to King and Powell (2007, The Natural History of Weasels and Stoats, Oxford University Press) the Least Weasel is the weasel that is the most narrow in its dietary preferences....eating almost exclusively on rodents and then focused primarily on voles (especially Microtus sp.).  I've caught Least Weasels on several occassions in drift fences in years past, so I wasn't totally shocked.  This is also not my first weasel post in the last year (see here).

But that doesn't mean I wasn't incredibly excited to see one!  The Least Weasel, in particular, is rare 'round it was quite a treat!  Holding still is not the strong-suit of these frenetic little forgive the blurry pics (these were the best of about 30 attempts).
Photo by N. Rudolph

Photo by K. Rutzen
Photo by K. Rutzen
I love me some Mustelids.....

A Size-13 Snapper:

Mid-summer is when I often do most of my turtle trapping.  As part of survey work this summer, I've been trapping in wetlands with the hopes of catching some Blanding's Turtles (Emydoidea blandingii).  I've caught a few (as you can see)....

We also catch many, many Painted Turtles (Chrysemys picta)....

Photo by N. Rudolph
Frequently these are given a unique mark.  This is done by notching the edge of their shells in a certain order with a file or dremel tool so that we can identify the turtles in the future.
Photo by N. Rudolph
But, in addition to the Painted Turtles, I almost always also catch Northern Snapping Turtles (Chelydra serpentina).  In fact, I would not be shocked if just about every water body in the state (from tiny pond to giant river) has at least one snapper lurking in the depths.  The Northern Snapping Turtle (previously called the "Common" Snapping Turtle) rarely leaves the water.  It doesn't usually sit on logs and bask in the sun, like many other pond turtles.  It mostly remains unseen in the mud and muck on the murky bottom.  The females are seen more frequently on land during the nesting season, when they must traverse the dangers of an over-land movement to lay their eggs.  It's during these times that snappers must frequently head out into vehicular traffic.  Poor snappers.  Especially considering that people apparently swerve to hit turtles crossing roads.

Regardless, the Northern Snapping Turtle is one of my favorite turtles: ornery, cantakerous, dirty, smelly, mean-looking.....everything I like in a critter :)
Photo by N. Rudolph
This summer, we've been lucky enough to catch many snapping turtles, like the individuals above.  At one particular pond, I caught at least five individual snappers in a single night that had carapaces (upper shells) which ranged from 8 to 12.5 inches.  The one below is a prime example.....
But that one pictured above wasn't even the biggest captured this summer.

That prize belongs to the individual below.  To put this into perspective, the boot on my chest-waders in this photo is a size 13.

It would be nice if more snapping turtles could make it to this size (or bigger). 

I guess we have to start by getting folks to restrain from hitting them on purpose (I can't believe I had to actually say that). 

Next we can try and come up with ways in which the average person can avoid hitting them on accident.


Sunday, June 23, 2013

Hunk O' Steamin' Bear

I wish I had more time for an in-depth post.

For now, the best I can do is show you a few video clips that my students working on the wolf project captured of curious upper Midwestern Black Bears (Ursus americanus).

Obviously, these critters weren't moving around too much in the winter during their first round of camera trapping on this project.

But, much to our satisfaction, they are showing up now....
....and about two days later....

We also got a clip of (what appears to be) a pretty massive individual.

For comparison, here's a White-Tailed Deer (Odocoileus virginianus) on the same camera at, what I *think* is, about the same distance.....

Followed by the steaming hulk....

Most of my projects don't occur in bear country, so these clips were a real treat.

Lots more to share when I get a sec.

For now I'll leave you with a few images of future naturalists helping me check turtle traps over the weekend.

Monday, June 10, 2013

Return of the Turtle Dogs!!

Photo by S. Wyrick

Sometimes I can't believe my good fortune.

But, as a wiser man than myself once said: "It's better to be lucky than good".  Can't remember who actually said it....but I'm pretty sure I first heard it from my dad.

Anyways.....those of you that have read my blog from the beginning (a small group, to be sure :)  ) might remember my past adventures with John Rucker and his Turtle Dogs.  This was back in 2011, when I still lived in North Carolina.  After my experience with John, I raved about the Turtle Dogs to my colleagues who work for the regulatory agency in the state where I currently live.

Well, this apparently snow-balled until....lo-and-behold.....John and his Turtle Dogs were up here this spring helping the state wildlife folks with surveys.  This time, however, we were not looking for the Eastern Box Turtle (Terrapene carolina) from down in NC.  The goal this time was the incredibly rare, and protected Ornate Box Turtle (Terrapena ornata). 

Turtles, in general, have it pretty rough.  They are slow to mature (taking decades in some species), they often experience reproductive failure (their nests are the focus of many mesopredators, like Raccoons, Skunks, Red Fox, Opossums); and even if the eggs survive, the hatchling turtles are bite-sized morsels for all of those same predators.  If anthropogenic influences were not a factor, being long-lived (and, thus, having many possible reproductive events possible in one's life) can help off-set high nest and juvenile mortality.  Yet, we no longer live in a land where anthropogenic influences can be avoided.  Habitat loss (particularly nesting habitat) have forced turtles to concentrate nesting activities in smaller and smaller suitable areas...where they are easy to find by mesopredators (who learn to return annually and can decimate a population's reproductive success).

One strategy to help off-set the low recruitment that many turtle populations experience is referred to as "head-starting".  Head-starting programs usually involve the harvesting of eggs from fresh turtle nests, the incubation of those eggs in captivity (so they avoid the nest-predators) and the eventual release of the hatchlings.  There are many pros and cons to head-starting of turtles that can be discussed.....but I feel this post is already growing a bit "wordy" we'll plunge on. 

But, the strategy of head-starting turtles becomes important later in my post.

John and his dogs worked with state regulators for the better part of a week in early May, surveying various sites for turtles.  Trying to assess populations and re-confirm box turtle presence at some of these sites.  Another goal of the dog surveys was to catch as many previously head-started box turtles as possible.  The head-starting program for this species in the state was instigated about 12 years ago....and many of the first head-started individuals should be of (or near) sexual maturity.

The best part?  Well, my colleagues at the state agency agreed to allow myself and a number of my students come with for a day.  This was a rare opportunity: using a unique survey method to catch rare species.  We needed to be at the top of our game! 

And, as usual, the weather was not on our side.....cold, windy and rain the night before.  Rain isn't good if you need dogs to follow a scent trail.  But...not much could be done about it. 

We also planned on spending alot of time pounding the ground doing visual surveys for turtles that the dogs may have missed due to poor environmental conditions.

We were scheduled to meet the dogs et al., at about noon.....but decided to start early and survey a site without the aid of dogs to help supplement their later surveys.

So our boots were on the ground by 10 am, and we walked parallel to eachother across the survey area.....
Luckily, the herps were still out, despite the cold....although we had to get on some steep slopes to find them (like this little box turtle).
A nice Racer (Coluber constrictor)....
...and even a beauty of a Bullsnake (Pituophis catenifer sayi).....
...this individual was nice enough to let us "probe" him.  Allow me to explain (very breifly below). 

The most definitive way to determine gender on a snake is to take a smooth and blunt metal stick (called a probe).  This stick is very thin and can be inserted into the cloaca of a snake (the area where the snake goes to the bathroom out of; see pic above).  If the probe goes in a distance that is approximately 1/3 of the snake's tail length, it's a male.  Why?  Because males have a bifurcated reproductive structure (or a structure with two "halves") called a hemipenis located there.   The hemipenis is essentially everted into the cloaca of the female during copulation.  They are often help the male get a grip (no arms or legs, remember) while sperm is transferred.  When males are not copulating, these hemipenes are inverted inside the base of the is the inverted hemipenis that accommodates the probe so that it slides into the cloaca. 

If it's a female snake....the probe wont slide in.

Make sense?  See more here.

ANYWAYS......our first visual survey was successfull.  Overall, we found five box Bullsnake and a few Racers.  By then, it was time to leave so we could meet John and the state wildlife folks at a different site. 

After our arrival, and general plan of attack was formulated, we headed out.  As a group, we hit the prairie, following John and the pooches as they went to work.

Part of our job was to supplement the dog surveys again with visual surveys.  The wet weather cold weather was hampering success.  Aside from affecting how long scent persists, the cold also meant the box turtles were probably not moving much (in other words, not leaving very long scent trails).

Yet, the dogs were happy and would not be deterred!
....soon a cry went up that they had found a turtle!  A sweet little female.... was our turn to shine.  Every time a turtle was caught (via dogs or visually) our students were jumping to their tasks.  In addition to assisting with the visual surveys, the students were responsible for flagging the location of capture with a number, putting that number on the turtle with marker on duct tape, getting a GPS reading, and bringing the turtle back to "base camp" for later processing.

Once the first turtles were taken back for processing, we continued on-ward....looking for more turtles....

Although the dogs were successful, we had nearly equal success doing visual surveys as the dogs did that day.  This is was much different than what I experienced in NC, and really enforces the importance of environmental conditions in the success of the dogs.

Ultimately, between the dogs and our own prowess, we found a decent number of turtles across the sites we surveyed.

These turtles above were all found at one of two sites we visited that day.  These were found by a combination of dogs and people
Photo by R. Jacques

The students also got to see a nice adult Blanding's Turtle (Emydoidea blandingii) that just happened to be on the roadside as we entered one of the box turtle sites....

A Blanding's Turtle (foreground) and two Ornate Box Turtles (Background)
Blanding's turtlees are aquatic, unlike the Ornate Box Turtle, which is fully terrestrial (land-dwelling).  Yet, the Blanding's Turtle has a higher domed shell than most of the aquatic turtles that folks are familiar with, such as Painted Turtles (Chrysemys picta).  The Blanding's also has a bright yellow chin and yellow plastron (lower shell) with dark patches on each scute. 

Note the yellow just barely visible on the chin of this Blanding's Turtle above (right)
Both of these species are very rare in our neck of the woods.  Loss of habitat (prairie for the Ornate Box Turtle and wetland for the Blanding's Turtle) have greatly impaced both species.  Their very slow development and high nest/offspring mortality rate also works against them, as with the Ornate Box Turtle.  Blanding's Turtles, for example, can take nearly 20 years to reach sexual maturity!

So....the turtles were gathered up and the students helped in weighing, measuring and marking the turtles prior to their return...
And, finally, the Pièce de résistance.....

One of the goals of these dog surveys was to assess how effective the headstarting program had been for the Box Turtles.  We were about 12 or 13 years post-initiation of this program in the state, which means that some of these headstarted individuals released at the beginning could now be sexually mature.

If it could be determined that some of the headstarted females were gravid (holding eggs), that would be a very good benchmark for success.

Luckily, the folks from a university further south were there with a portable ultra-sound unit to see if any of the gals might be carrying babies....

Now...while I don't want to give away all of the suprises....I will say that the gals examined with the ultra-sund looked to be carrying alittle extra baggage :)

And, so it was that our first day of turtle surveys ended.  The surveys were mostly successfull and my students made me very happy, by doing such a great job (the state regulators we were out with commented on this to me as well).

Did I say "first day"?  That's right!

More to come!