Intact landscape promotes gene flow and low genetic structuring in the threatened Eastern Massasauga Rattlesnake. Issue 11 (2nd May 2021)

• Record Type: Journal Article
• Authors: Kudla, Nathan; McCluskey, Eric M.; Lulla, Vijay; Grundel, Ralph; Moore, Jennifer A.
• Is Part Of: Ecology and evolution. Volume 11:Issue 11(2021)
• Page Start: 6276
• Page End: 6288
• Publication Date: 2021-05-02
• Subjects: dispersal -- fragmentation -- Island -- reptile -- Snake -- spatial genetics -- species distribution modeling; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.7480
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Genetic structuring of wild populations is dependent on environmental, ecological, and life‐history factors. The specific role environmental context plays in genetic structuring is important to conservation practitioners working with rare species across areas with varying degrees of fragmentation. We investigated fine‐scale genetic patterns of the federally threatened Eastern Massasauga Rattlesnake ( Sistrurus catenatus ) on a relatively undisturbed island in northern Michigan, USA. This species often persists in habitat islands throughout much of its distribution due to extensive habitat loss and distance‐limited dispersal. We found that the entire island population exhibited weak genetic structuring with spatially segregated variation in effective migration and genetic diversity. The low level of genetic structuring contrasts with previous studies in the southern part of the species' range at comparable fine scales (~7 km), in which much higher levels of structuring were documented. The island population's genetic structuring more closely resembles that of populations from Ontario, Canada, that occupy similarly intact habitats. Intrapopulation variation in effective migration and genetic diversity likely corresponds to the presence of large inland lakes acting as barriers and more human activity in the southern portion of the island. The observed genetic structuring in this intact landscape suggests that the Eastern Massasauga is capable of sufficient interpatch movements to reduce overall genetic structuring and colonize new habitats. Landscape mosaics with multiple habitat patches and localized barriers (e.g., large water bodies or roads) will promote gene flow and natural colonization for this declining species. Abstract : We investigated fine‐scale genetic patterns of the federally threatened Eastern Massasauga Rattlesnake ( Sistrurus catenatus ) on a relatively undisturbed island in northern Michigan, USA. We detected an isolation‐by‐distance pattern and weak genetic structuring with spatially segregated variation in effective migration and genetic diversity. The lack of strong genetic structuring in this intact landscape suggests that the Eastern Massasauga is capable of sufficient interpatch movements to colonize new habitats and maintain gene flow at this scale. ​