Snake X-ing: Massasaugas and the dangers of sunbathing

I’ve decided to stick with herps for my second #scicomm post. This time we’ll be talking about rattlesnakes, specifically the Eastern Massasauga (Sistrurus catenatus) which is currently listed as threatened throughout its entire range.

 Figure 1: Range map for the Eastern Massasauga

The massasauga, like all other reptiles, is an ectotherm meaning that they need to use outside forces to regulate their internal temperature (thermoregulation). This strategy for thermoregulation becomes a problem when the environment they require for that action has been changed. Yes, we’re taking about habitat degradation again. Humans are really good at it.

Massasaugas primarily live in wetlands, lowlands, and riparian areas. These areas have perfect basking sites – regions where an individual can intentionally go out and warm up under the sun (Harvey and Weatherhead, 2010).  Unfortunately for the massasauga, a lot of these spaces have been taken by humans for urbanization and agriculture.

A lot of reptiles live in warm, typically sunny environments that provide plenty of basking sites regardless of human interference. However, the massasauga is a temperate species, ranging through the American Midwest region. Because of the area’s lower average temperature and natural geography – more forests and woodlands rather than open prairie and scrubland – the basking sites they do have are crucial. Loss of these important sites causes massasaugas to look for other alternatives, which in this case means roads. Where there are roads, there are cars and in the fight of snake vs F-150, the truck wins. Every time. Roadkill accounts for a very large proportion of human related deaths for massasaugas (Jones et al, 2012).

And that’s not the only human problem that massasaugas face.

Historically, public opinion has not been on the side of snakes. Rattlesnakes get a particularly bad rep. It’s understandably hard to be considered beneficial or cute when you’ve got a mouth full of venom. However, human fear leads to aggressive action when it comes to massasaugas. The first response of many people when confronted with a massasauga is to kill it and this practice along with habitat loss is what has severely depressed the massasauga’s population numbers. In order to combat this, local DNRs and the federal government have been attempting to educate the public on their importance. Massasaugas eat small mammals, birds, and other vertebrates, making them an important source of pest control in their ecosystems. They also serve as an important source of food for larger predators. This, along with making snake removal an option in more regions has helped cut down on direct human mortality. There has also been a recent management effort to create new basking sites in protected areas to reduce their roadkill mortality.

Learn more about massasauga research here:

  1. Jones PC, King RB, Bailey RL, Bieser ND, Bissell K, Campa III H, Crabill T, Cross MD, Degregorio BA, Dreslik MJ, Durbian FE. Range‐wide analysis of eastern massasauga survivorship. The Journal of Wildlife Management. 2012 Nov;76(8):1576-86.
  2. Weatherhead PJ, Prior KA. Preliminary observations of habitat use and movements of the eastern massasauga rattlesnake (Sistrurus c. catenatus). Journal of Herpetology. 1992 Dec 1:447-52.
  3. Harvey DS, Weatherhead PJ. Habitat selection as the mechanism for thermoregulation in a northern population of massasauga rattlesnakes (Sistrurus catenatus). Ecoscience. 2010 Dec 1;17(4):411-9.
  4. US Fish and Wildlife Service
  5. Photos: USFWS, Creative Commons, and New York State Conservation Site

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