Movements of the Eastern Ribbonsnake (Thamnophis sauritus) in Nova Scotia

Abstract

The disjunct Eastern Ribbonsnake (Thamnophis sauritus) population in southwest Nova Scotia is listed as “threatened” by the committee on the Status of Endangered Wildlife in Canada. A study of the movements of the species at two lakeshore locations known to support a high density of Eastern Ribbonsnakes was undertaken in 2007 and 2008. Average seasonal movements at both sites ranged from 17 m to 84 m for juvenile snakes and 21 m to 130 m for adults; one neonate was recaptured during the study after travelling 32 m. The maximum distance travelled by an individual snake was 391 m in one season. The best-fit model to explain differences in daily movement patterns included year (P = 0.041), indicating that there is annual variation in the movements of this species. Low recapture rates precluded accurate estimates of home-range size, which varied roughly from 0.16 ha to 0.78 ha. Both movements and home ranges were larger than previously documented in Nova Scotia, but maximum distances travelled were consistent with a previous study in Michigan. Most documented movements were along the lakeshore within contiguous, suitable habitat. More work is needed to understand the frequency of large movements and triggers that initiate movements, e.g., changes in water levels, habitat suitability, or prey availability.