Manipulation of basking sites for endangered eastern massasauga rattlesnakes

Abstract

Generating open-canopy basking sites via manipulation of vegetative cover has been proposed as a conservation strategy for snakes and other reptiles. We assessed how endangered eastern massasauga rattlesnakes (Sistrurus catenatus) responded to 2 types of manipulations at a wetland site in New York, USA: 1) cutting shrubs to create ≤100-m2 plots within known gestation areas in 2008, 2011, and 2012, and 2) cutting tree and shrub cover in the adjacent forest to create a 4-ha forest clearing in 2011. Based on systematic visual surveys from June to August in 2011 and 2012, we estimated snake presence among manipulated and unmanipulated plots in response to plot treatment date. We observed massasaugas selecting newly manipulated plots more often than unmanipulated plots within known gestation areas in both 2011 and 2012, but we detected no increase in massasauga activity within the adjacent forest clearing in either year. The effectiveness of vegetation cutting appeared to decline after 3 years because of vegetation re-growth. We suggest that cutting shrubs to ≤0.25 m in height can benefit this population of rare snakes, which faces limited availability of basking sites because of vegetative succession. © 2016 The Wildlife Society.