Monday, April 2, 2018

Crotalus Adamanteus


The highlight of one of our class' field trips in Francis Marion National Forest was getting to meet "Venus", a Southern Diamondback Rattlesnake, Crotalus adamanteus. She is the subject of a government-funded group whose aim includes studying her species. To better understand her life and her day-to-day functioning, a radio frequency tracker, such as the one in the picture below, was placed on her rattle. This device enabled us to be able to "track" her using a radio frequency.
When we finally came across her, she was hiding in the underbrush. She was camouflaged so well, she could have easily been overlooked and stepped on; this was very eye-opening! For all the tracking in the woods I'd done while growing up, I'm sure I've been in the company of C. adamanteus without even knowing it.
C. adamanteus is a terrestrial species that occupies the southeastern United States, from southeast North Carolina to Florida and eastern Louisiana. They belong to the family Crotalidae which consists of venomous snakes. Their triangular head allows enough space for the venom glands, and also houses their hinged fangs. They have vertical pupils and bilateral facial pits between the eye and nose that aid in infrared heat sensing, both are utilized in hunting and defense. Distinguishable traits include the presence of a rattle; 2 prominent light lines on the face; vertical light lines on the snout; and large, clear cut, light bordered diamonds on the back. The life history of C. adamanteus is direct development, more specifically ovoviviparity. This species is venomous but is rather laid back and will not become defensive unless they feel threatened. 
This species population size is currently decreasing due to urbanization/loss of habitat, as well as increased hunting for their skin in which products are made and sold. There are many organizations that try to preserve this species as well as bring light to the declining population.

Works Cited
Hammerson, G.A. 2007.  Crotalus adamanteus. The IUCN Red List of Threatened Species 2007: e.T64308A12762249. http://dx.doi.org/10.2305/IUCN.UK.2007.RLTS.T64308A12762249.enDownloaded on 02 April 2018.
Pough, F. Harvey. Herpetology. Sinauer Associates, Inc., Publishers, 2016.

3 comments:

Allison Welch said...

Such an impressive snake!

Anonymous said...

I really enjoyed taking a look at this snake as well! I think its interesting and worth while to study these animals and getting a look at how they track them with the transponder and frequency reader was very insightful as to what is like to track these animals in practice. Taking a look at different ways to study snakes I saw that there is also technology for mark and recapture with an electronic chip- they insert these "pit tags" in the perennial cavity. They are then able to monitor snake populations, repudiative rates, and general snake heath for conservation efforts. I wonder if their program has considered this practice or if they currently employ it?

Heres a little video:
https://www.youtube.com/watch?v=5DR50IgvE7g

Allison Welch said...

PIT (passive integrated transponder) tags are the same as microchips for pets - they contain uniquely identifying codes, but cannot be sensed from a distance. They're well-suited for mark-recapture studies (i.e., when you already have a way to locate the animals) but not for tracking studies (i.e., when the goal is to locate the animals). Both PIT tags and radio-transmitters are very useful technologies, but for different purposes!