| Michigan is considered the last stronghold for the Eastern Massasauga Rattlesnake (EMR, Sistrurus catenatus catenatus), where it is a species of special concern. Understanding the habitat ecology and characteristics of EMR populations is essential to conservation efforts. Populations of EMRs have not been previously examined in southwestern lower Michigan. The objectives of this study were to quantify movement and habitat use patterns, develop a habitat suitability model, and conduct a population viability analysis (PVA) for EMRs in southwestern lower Michigan. The study was conducted at 2 sites in Barry County, Michigan. EMRs (n = 12 in 2004, n = 18 in 2005) were captured, implanted with radio transmitters, and tracked daily throughout the April--October. Data were collected on snake location, vegetation type, structure, and composition, and population demographics. Mean 95% fixed kernel home range size was 2.8 ha. EMRs most commonly used early successional deciduous upland and wetland vegetation types. Suitability of vegetation types increased with higher percentages of live (62-71%) and dead (90-96%) herbaceous cover and decreased as stem density and absolute dominance of trees/shrubs >3 m tall increased. Based on PVA simulations, populations may be increasing over the next 50 years if following an extant trajectory. Caution must be used when applying these results due to data variability. Results of this study have implications for future conservation of EMRs in the area. |
