Texas Ratsnake Predation on Southern Flying Squirrels in Red-Cockaded Woodpecker Cavities

Abstract

Elaphe spp. (ratsnakes) are frequent predators on cavity-nesting birds and other vertebrates, including Glaucomys volons (Southern Flying Squirrels). They are known predators of Picoides borealis (Red-cockaded Woodpeckers), especially during the nestling phase. Picoides borealis cavities are frequently occupied by Southern Flying Squirrels, often several squirrels per cavity. Behavioral aspects of ratsnake predation on flying squirrels in woodpecker cavities is an important component required for a full understanding of the potentially complex interaction between Red-cockaded Woodpeckers, Southern Flying Squirrels, and ratsnakes. We induced previously captured Elaphe obsoleta (Texas Ratsnake) to climb boles of pine trees and gain access to Red-cockaded Woodpecker cavities known to contain Southern Flying Squirrels, and observed the resulting predatory interactions. Eight of nine ratsnakes successfully captured 14 of 22 Southern Flying Squirrels present in the cavities.