Eastern Massasauga Research
The Western Pennsylvania Conservancy (WPC) and The Pennsylvania Natural Heritage Program (PNHP) visited and investigated the presence of the eastern massasauga (Sistrurus catenatus catenatus) at 63 historic locations in western Pennsylvania. Over the past century in Pennsylvania, the eastern massasauga has declined from 19 populations in six western Pennsylvania counties to only four isolated populations in Butler and Venango counties. Of the 63 locations investigated, two are believed to have been reported erroneously, four have massasauga present, 19 are doubtful for the support of populations, and 38 are considered extirpated. This has happened despite documentation of the decline, identification of contributing factors, and state listing as endangered species. Habitat loss, once most prominently from destruction of wetlands, is now primarily from forest succession and is the main factor for the modern-day decline. If this habitat loss remains unchecked, it will likely result in the extirpation of the remaining populations.
Radio Telemetry (2005-2006)
As WPC considered ways to help conserve this species, an important piece of information was missing; the way that massasaugas use the habitat and the role that temperature plays in movement and hibernation. To better understand the ecology of these animals within specific locations in Pennsylvania, we undertook a study of movement of individual snakes over a two year period. In all, 51 free-ranging individuals - 17 gravid (pregnant) females, 7 non-gravid females, 12 males, and 15 juveniles - were radio-equipped with temperature sensitive radio transmitters and monitored every 48 hours.
Through completing this telemetry project WPC and PNHP concluded that adult massasauga in Pennsylvania had a mean home range of 3.8 acres, and mean total distance moved over a season of 2,465 feet. Gravid females had smaller home ranges and movement parameters than males, non-gravid females, and postpartum females. When tracked over the entire activity season, there was no significant difference in the home ranges or movements of snakes of different sexes or reproductive conditions.
Seasonal movements were characterized by a general tendency to remain in or near hibernacula in the spring, followed by an expansion of home range and movement to surrounding areas of drier/upland habitat dominated by forbs and open canopy in the summer. In autumn, massasauga showed a gradual return to the hibernacula, with a preference for areas with forbs and open canopy. Gravid females showed a particular preference for dry areas of very low vegetation, often in proximity to shrubs. Fields of forbs and low-growing grasses with an open canopy and spotty distribution of woody shrubs characterize the habitat of the massasauga in Pennsylvania. Habitat is consistently found in proximity to wetland soils. Snakes of different age and fitness respond to subtle differences in micro-habitat that meet their individual needs and this is true throughout their life histories.
Conservation, Habitat Planning, and Management (2007- present)
Information gathered from our studies provided the framework for a comprehensive conservation and management plan for the eastern massasauga, which includes habitat management recommendations. This plan was submitted to the Pennsylvania Fish and Boat Commission (the jurisdictional agency for the species) and is being used to guide conservation work for the massasauga in Pennsylvania.
In addition to the radio telemetry studies, WPC and PNHP investigated the effects of various treatments upon the habitat of the eastern massasauga hoping to glean which methods of habitat management are most effective. This work took place on public lands in Butler and Mercer counties in western Pennsylvania. We removed all woody vegetation from 0.6-acre study plots that included both shrub habitat and closed-canopy (wooded) habitats. Habitat was assessed before and after treatments, and comparisons will be made with the habitat used by massasauga during the previous two-year radio telemetry study. By varying treatments (hand cutting, mechanical cutting, prescribed fire, and/or cutting combined with prescribed fire), we hope to gain experience in effectively creating habitat that resembles the habitat chosen by massasauga. We will then be able to make recommendations (including cost effectiveness) to landowners about habitat management for massasauga on their properties.
Recently, WPC has implemented habitat management recommendations on private lands where the massasauga and its preferred habitat are being threatened by woody vegetation succession. With the support from and cooperation of private landowners and private foundations, WPC has managed and restored approximately 20 acres of habitat.