Early emergence and seasonality of the Red-bellied Snake (\u3ci\u3eStoreria occipitomaculata\u3c/i\u3e) along the Platte River in south-central Nebraska, USA

The Red-bellied Snake (Storeria occipitomaculata) primarily inhabits moist woodlands of eastern North America, with two disjunct populations occurring in the Great Plains, one of which is in south-central Nebraska. This species is listed as at-risk in Nebraska, in part, due to being uncommon with limited information available about the ecology and natural history of this isolated population. We amassed 48 observations of Red-bellied Snakes in Nebraska from museum specimens and published accounts, including our observations and others reported to us published herein. The previous earliest documented date of spring emergence was 6 April from a specimen collected in 1999. On 12 March 2016, we observed an adult Red-bellied Snake along the Platte River in Buffalo County, Nebraska, which predates the previous earliest documented emergence date by almost a month. It is unclear whether our observation represents an unusual behavior related to an unseasonably warm winter or a normal occurrence that has remained undocumented for this secretive, uncommon snake. Our summary of observations in Nebraska demonstrates Red-bellied Snakes are active March through October, with peaks in observations in April/May and September. This disjunct population occurs within the Big Bend Reach of the Platte River in south-central Nebraska, which is a major spring stopover site for migratory Sandhill Cranes (Antigone canadensis). Emergence in March by these snakes greatly increases predation risks by opportunistically foraging cranes. Additional ecological information is warranted for this disjunct population, as use of the Platte River flood plains by Sandhill Cranes has increased during the last half century, and removal of riparian forests has been a common habitat management practice for Sandhill Cranes and endangered Whooping Cranes (Grus americana)