Occurrence of the Red-bellied Snake (Storeria occipitomaculata) on the margins of a disjunct range

Abstract

The Red-bellied Snake (Storeria occipitomaculata) can be found throughout much of eastern North America, though two notable disjunct populations exist in the Black Hills of southwestern South Dakota and the Central Platte River Valley in southcentral Nebraska, west of the species’ core range. While literature continues to be added on the Red-bellied Snake and its natural history, it remains largely understudied in Nebraska. Throughout much of this species’ range, it is considered associated with woodland and wetland habitat features. On 28 September 2021, we detected one Red-bellied Snake near a treeless playa wetland in the Rainwater Basins ecoregion of southcentral Nebraska. Using a Grubbs Test to determine significant outliers, we found that this record was further from the Platte River than other previous accounts of this species in the state. This observation suggests this species may be found in other portions of the Rainwater Basins and considerably further from the Platte River than previously believed. Our observation along with other recent work indicates that Red-bellied Snakes may persist in herbaceous habitats lacking established woodland that include sufficient wetland features to support their primary food sources, including gastropods and other soft-bodied invertebrates. Due to the fragmentation of suitable habitats in the Rainwater Basins, coupled with the low dispersal of Red-bellied Snakes, populations persisting in the region are likely to be isolated.