Habitat Management for the Eastern Massasauga in a Central New York Peatland

Abstract

The eastern massasauga rattlesnake (Sistrurus catenatus catenatus) is rare throughout much of its range, especially where this species is associated with weakly minerotrophic peatlands. Because such habitats can rapidly become unsuitable through succession, we established experimental plots to evaluate the effects of cutting, burning, herbivore exclusion following cutting and burning, and herbicide application on eastern massasauga habitat. After the first growing season, shrub density, shrub basal area, and shrub height were greater (P = 0.008) in cut-only (CO) areas than in areas that were cut-and-burned (CB). After 3 years, only shrub height continued to be greater in CO areas (P = 0.001). Both basal area and shrub height increased in both treatments at the same rate, while the shrub mountain-holly (Nemopanthus mucronata) became less important in the plots over time; however, this species still maintained the highest importance value (IV) over the 3-year study period. We conducted a second experiment to evaluate browsing by mammals and found shrub height increased in all treatment types over the 2 years monitored (P = 0.009) and, at the end of the first year, was consistently greater in CO plots (P = 0.001). At the end of the second year, this relation held only in fenced compared to unfenced plots, indicating that browsing had a significant effect on growth in shrub height. The herbicide glyphosate was very effective when applied as a broadcast foliar spray. Abundance and diversity of small mammals in the shrub peatland were lower than in surrounding forested wetland habitat. Over the 3-year monitoring period, abundance and diversity of small mammals increased in the treated areas of the shrub peatland; however, it is unclear if this increase was a permanent or a transitory effect. Data on eastern massasauga use of these cleared areas were inconclusive; however, 9 of 89 (10.1%) aboveground radiolocations from 9 individual snakes tracked in 1991 occurred in or around treatment areas that constituted only 2.5% of the total peatland area.