Wednesday, April 29, 2015

Guest student post: Eastern Massasauga Rattlesnake by Roberto

Eastern Massasauga Rattlesnake (Sistrurus catenatus catenatus)
Eastern Massasauga (Sistrurus catenatus) Photo by Mike Redmer, USFWS

http://labs.russell.wisc.edu/zuckerberg/research/climate-change-vulnerability-assessment/
Systematics
The eastern massasauga is actually considered a subspecies of the species S. catenatus, with the other two being the desert (S. c. edwardsii) and western (S. c. tergeminus) massasauga rattlesnakes. They belong to the order Squamata and family Viperidae (vipers and pit vipers).

Ecology
1http://www.machac.org/project_categories/featured-project/

The eastern massasauga ranges from central New York and western Pennsylvania all the way through to Ohio, southwestern Ontario, Michigan, Indiana, Illinois, southern Wisconsin, eastern Iowa, southeastern Minnesota, and central Missouri. In PA, this rattlesnake inhabits a couple of different habitats depending on the season, from open fields to remnant prairies and shallow, open wetlands. During the winter, they will find and burrow into previously dug-out tunnels and holes made by crayfish and moles in the rush-sedge marshes and mixed forbs. Adult eastern massasaugas prey on small mammals, typically rodents including meadow voles, short-tailed shrews, and white-footed mice, but it may eat the occasional nesting bird or frog. Broods average at about seven young every 2-3 years from mid-August to September, but the brood can range from 3-19 snakes. It takes anywhere from 2-4 years to reach sexual maturity, but it’s lifespan can exceed 20 years.
Parkhill Prairie crayfish burrow                                           
              
http://www.arkive.org/parkhill-prairie-crayfish/procambarus-steigmani/image-G98970.html and http://www.fcps.edu/islandcreekes/ecology/meadow_vole.htm
Reproduction
Mating seems to occur in late July/August, with females giving birth to live young the following August/September. Males compete for the females during the summer, and a female will store deposited sperm until after hibernation in the spring.  During gestation, the females will often bask in exposed areas with little to no vegetation. The young actually develop in eggs, but the eggs hatch while still within the female’s body, so the snakes come out as live young.

Threats
The main threat to the eastern massasauga population in PA is habitat loss driven by human activity and natural forest succession. Wetland habitats that would be used for overwintering are drained for farms or flooded, while forests reclaim the fields and prairies used for food and reproduction. Eastern massasaugas are not distance travelers, so they require the fields and wetlands close to prairies. Towns, roads, and farm fields prevent migration between the areas for the snakes, isolating them to small populations that ultimately die off. To a lesser degree, the population was also affected by the outright killing of eastern massasaugas by people because of their venomous capabilities. At one time, many states had bounties on rattlesnakes like the eastern massasauga, showing how much people went out of their way to kill them.

Management
In order to save the species, areas with surviving populations should be secured and managed, with a goal of increasing habitat area. Succession of woody vegetation should be controlled so that the habitat is not lost, and secured areas should mitigate any harmful effects done by human activity on the eastern massasauga or the habitat. Precautions should be taken, like analyzing the impact a project might have on the population beforehand. Additionally, education services providing accurate information on the importance of eastern massasaugas meant for dispelling any previous inclinations of the snake should be implemented, as people tend to focus on the venom it carries and not the role it has in the environment.

References


Climate Change Vulnerability Assessments." Zuckerberg Lab. N.p., 20 Dec. 2013. Web. 18 Mar. 2015. <http://labs.russell.wisc.edu/zuckerberg/research/climate-change-vulnerability-assessment/>.

"Eastern Massasauga Rattlesnake." USFWS: Eastern Massasauga Fact Sheet. U.S. Fish and Wildlife Service, n.d. Web. 18 Mar. 2015. <http://www.fws.gov/midwest/endangered/reptiles/eama/eama-fct-sht.html>.

"ITIS Standard Report Page: Sistrurus Catenatus Catenatus." ITIS Standard Report Page: Sistrurus Catenatus Catenatus. U.S. Fish and Wildlife Service, n.d. Web. 18 Mar. 2015. <http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=209510>.

Meadow Vole." Meadow Vole. FCPS, n.d. Web. 19 Mar. 2015. <http://www.fcps.edu/islandcreekes/ecology/meadow_vole.htm>.

"Parkhill Prairie Crayfish Photo." Procambarus Steigmani. N.p., n.d. Web. 20 Mar. 2015. <http://www.arkive.org/parkhill-prairie-crayfish/procambarus-steigmani/image-G98970.html>.

"Pennsylvania Amphibian and Reptile Survey." MACHAC. MACHAC, n.d. Web. 19 Mar. 2015. <http%3A%2F%2Fwww.machac.org%2Fproject_categories%2Ffeatured-project%2F>.

Brittingham, Margaret C., Timothy Maret, and Joseph Merritt. Terrestrial Vertebrates of Pennsylvania.  Ed. Michael A. Steele. Baltimore: Johns Hopkins University Press, 2010. Print.

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