Thursday, September 27, 2012

Field Ecology Methods Week 2 (2012): Reptiles

After a week of invertebrates and Limnological techniques, the students spent some time learning how to conduct some standard surveys for reptiles.

First, we checked the existing artificial cover objects on-site for snakes....

This resulted in only TWO juvenile Gartersnakes (likely born this year).  But it was unseasonably warm on the day we checked the boards (upper 80's)....probably too warm for snakes.

The students then worked to measure out additions to our existing coverboard grid. 

Few things make me happier than to see all 18 of these students working hard in the field and no one standing idle.

Let's face it....field work can be grueling (especially in the warm conditions we had while deploying the boards).  But, this gives the students a small taste of less than ideal field conditions that one might face as a field ecologist.  It's not all catching Cougars and Narwhals every second (or as a colleague here says...there's not a "gorilla behind every tree").

After the artificial cover objects were laid, we moved over to the creek and deployed some hoop traps for turtles.


The traps sat for a night, and a small group of volunteers came out with me the next morning to check and re-bait the traps.

Thankfully, we had more luck with turtles than with snakes.

Two large adult Snapping Turtles (Chelydra serpentina).....

Five cute little Painted Turtles (Chrysemys picta).......

We took our morphological measurments, such as carapace (or upper shell) length....

Then we released the turtles back into the stream.

The next day it was back to check the traps again, and this time the entire class was present.

...and once again, we had good fortune!

Day 2 yielded 14 painted turtles and one little snapper....a good haul!
Once again, appropriate morphological measurments were made....the turtles were given a permanent mark....and released back into the creek. 

Hopefully, we'll see some of them again in the spring!

For more information on standard survey techniques for reptiles, see this excellent new book:

McDiarmid, R.W., et al. 2012 Reptile Biodiversity: standard methods for inventory and monitoring. University of California Press. Berkeley.

The following book is also a good introduction to standard reptile survey methods.  Unfortunately, it's out-of-print, but you can still get it from libraries or through interlibrary loan.

Karns, D.R. 1986. Field Herpetology: methods for the study of amphibians and reptiles in Minnesota. Occassional Paper 18 of the James Ford Bell Museum of Natural History, University of Minnesota.


  1. I see 5 little painted turtles or did you decide that only 4 of them were cute and an ugly one didn't count?

    Looks like a lot of fun though!

    1. Well, the one on the far right isn't as cute as the others. got me. I was in a rush when I finished this.

      Thanks for catching it....correction made! :)

  2. How do you permanently mark the turtles?

  3. You can file a notch in their marginal scutes in a specific order based on what number you want your turtle to be marked. I use a system slightly modified from what Cagle published in the 50s. All scutes moving left from the central or nuchal scute are considered the 10s....and scutes to the right of the nuchal scute are the 1s. If your turtle is number 23, you would file a notch in the second scute to the left of the nuchal scute, and file a notch in the third scute to the right of the nuchal scute.

    Cheap and easy way to mark turtles!