Wednesday, March 23, 2011

A Good Day for Herps!

The posts will come more frequently in the spring, I imagine. 

Especially now that the herps are active, as I'll have more to talk about in between camera trap photos!

As a little background, let me tell you about this project.  I have two study sites that I'm comparing mammal and herp communities at.  The camera traps are part of that project, but I've also got a suite of other survey equipment deployed for small mammals and herps.

At each site we are surveying three habitats.  In each habitat we have a transect of 10 cover boards and a drift fence (200 ft of fencing with three types of live trap: funnel traps, box traps and pitfalls). 

So, for those of you keeping track, that's 60 coverboards (hauled out on the back of your's truly last year) and 1,200 ft of fence dug in (again, by your's truly).  The boards create cover, and a microclimate beneath that are attractive to herps and small mammals.  They are passive, so you can go out and flip them whenever.  The drift fences also capture herps and small mammals.  Problem is, they are not passive.  If the traps are engaged, you have to check them every 24 hrs and release the critters captured.

We are also supplementing with sherman traps (only for small mammals).

So, I run the surveys in the summer and off semesters, and in the semesters that I teach Wildlife Ecology, the students run the surveys as part of their lab exercises.

Two weeks ago, the drift fences were opened for the first time (no class this it's done by me, or any student willing to volunteer).  Because the semester is still in session, time is limited, and we are only opening them for one or two 24 hr perios per week.

In the first week: no captures.
In the second week: a single cricket frog and a white-footed mouse (and that's it for ALL of that survey equipment!).

Clearly, stuff was not ready to start hopping yet.

Today, I had the first good haul of herps to indicate the season is upon us (I hope!).

First, in one of the grassland coverboard transects, got a cute little juvenile racer (Coluber constrictor).

Although the adults are typically a sleek black (with a white chin), hatchling racers are patterned.  This pattern is retained by juveniles (as seen in the pics above) for a time and fades as they grow to adulthood.   Racers are aptly named.  They can move like the dickens and even an experienced herpetologist can loose them in long grass or brushy edges should they take off.  Luckily it was cool this morning when I checked the boards, and this guy wasn't moving very I was able to snap a few pics!  Although the specific epithet "constrictor" implies....well...something that constricts, racers typically don't.  They often prey on animals they can overpower without constriction....although bigger prey may be held down with a coil or two.  They hunt by smell, but also by sight.  Nussbaum et al. 1983 report that they are able to detect crickets up to 50 METERS away, and can see larger prey at even greater distances!  Their dietary choices are not narrow. 

In fact, Uhler et al. (1939) reported the prey occurence (by volume) in the stomachs of racers surveyed in Virginia as follows:
  • snakes=26%,
  • birds=18%,
  • shrews=12%,
  • caterpillars and moths=10%,
  • frogs=9%,
  • moles and lizards=6%,
  • squirrels=5%
  • other insects/arthropods=5%
Hamilton and Pollack (1956) found the percent occurrence of food types selected by racers in Georgia to be as follows:
  • Lizards=65%
  • Snakes=28%
  • amphibians=9%
  • mammals=3.5%
  • insects=1.7%
In North Carolina, Brown (1979) found that reptiles, mammals and insects made up roughly 80% of selected prey.

Interestingly, a different trend was observed in Illinois by Klimstra (1959):
  • insects = 48%
  • mammals = 43.5%
  • birds = 16.5%
  • THEN reptiles= 12%.
A similar trend was also reported by Fitch (1963) for racers in Kansas:
  • Insects = 77%
  • mammals = 15%
  • snakes = 5%
So, not only do they have broad dietary interests, they also vary greatly by geographic location.


My next coverboard discoveries occurred in the woods, specifically in lowland deciduous woods.  There is a wooded riparian area (stream corridor) nearby, and a number of ephemeral wetlands in the general vicinity.  That means one thing!  GREAT SALAMANDER HABITAT!

The first volunteer was a very young white-spotted slimy salamander (Plethodon cylindraceus).  He was under a board located within 15 ft of an ephemeral pool.  He was so small that I actually almost didn't see him.

I had found many young slimy salamanders at this site last year, but no big adults.  That changed today, however!  I found a big male under a different board in the same transect.

Slimy salamanders are members of the family Plethodontidae, which are generically referred to as the "lungless salamanders".  The name is accurrate, as members of this Family truly have no lungs!  They absorb oxygen through their skin (called cutaneous respiration).  The taxonomy of the "slimy salamander complex", specifically, is amazingly confusing and constantly in flux.  Members of this "complex" are found throughout the southeastern and eastern USA.  According to Beane et al. (2010), all slimy salamanders in our region were once thought to be a single species (P. glutinosus).  These have now been split into 4 species that exist in the state: P. glutinosus, P. cylindraceus, P. chattahoochee and P. chlorobryonis

Luckily, in my particular part of the state, I only have to worry about one (P. cylindraceus, the white-spotted slimy salamander).  Whew!


I round out this post with another coverboard encounter: the spotted salamander (Ambystoma maculatum). 

A member of the family Ambystomatidae (the "mole salamanders") these chucky little salamanders are fairly common in this region of the state.  Amazingly, I had not found one until today!  So, I added a new species to the list for one of my sites.  The breeding season for this species is late winter, early spring and has already passed.  I imagine this fella was taking advantage of the nice cover created by the board and will soon move on to his permanent borrow for the summer.

Drift fence captures to be reported in the future!

Literature Cited:

Beane, J.C., J.C. Mitchell, W.M. Palmer, and J.R. Harrison III. 2010. Amphibians and Reptiles of the Carolinas and Virginia (2nd edition).  University of North Carolina Press.

Brown, E.E, 1979.  Some snake food records from the Carolinas. Brimleyana 1:113-124.

Fitch, H.S. 1963. Natural history of the racer Coluber constrictor.  University of Kansas, Publications of the Museum of Natural History 15:351-468.

Hamilton, W.J., Jr., and J.A. Pollack. 1956. The food of some colubrid snakes from Fort Benning, Georgia. Ecology 37:519-536.

Nussbaum, R.A., E.D. Brodie, Jr., and R.M. Storm. 1983. Amphibians and reptiles of the pacific northwest.  University of Idaho Press.

Klimstra, W.D. 1959. Food of the racer, Coluber constrictor, in southern Illinois. Copeia 1959:210-214.

Uhler, F.M., C. Cottam, and T.E. Clarke. 1939. Food of snakes of the George Washington National Forest, Virignia. Transactions of the North American Wildlife Conference 4:605-622.


  1. Nice finds and very interesting information on the racer diet studies. The spotted salamander looks huge.

  2. Yeah, Racers are very cool. Down here they are one of the species I most commonly encounter (well, that and the little wormsnake). Alot different than back home in WI, where they are protected by the DNR.

    Spotted Sallys are good-sized (as are many of the "mole salamanders", but nothing compared to the tiger salmander (A. tigrinum), which is a monster!

    Thanks for reading!

  3. True the tigrinum can get quite large, but I think our Dicamptodon still beats it :)

  4. Man...Dicamptodon is a cool critter! Never seen one, myself...but would love to.