Reexamination of Herpetofauna on Mormon Island, Hall County, Nebraska, with Notes on Natural History

Authors

Keith Geluso, University of Nebraska—KearneyFollow
Mary J. Harner, The Crane TrustFollow

Date of this Version

5-17-2013

Document Type

Article

Citation

Transactions of the Nebraska Academy of Sciences 33 (2013), 7–20

Comments

Copyright (c) 2013 Keith Geluso and Mary J. Harner.

Abstract

The Platte River in central Nebraska, USA, was historically surrounded by mixed grass and tallgrass prairies and wet meadows, but many of those habitats were lost or altered during the last century with unknown effects on animals that reside in them. Researchers first surveyed herpetofauna on part of a large island preserve in the Platte River, Mormon Island, Hall County, Nebraska, in 1980 when the land was protected for conservation. They documented 10 species, including three species of amphibians and seven species of reptiles. We inventoried herpetofauna after 30 years of conservation management on Mormon Island and adjacent Shoemaker Island. We captured four species of amphibians and 11 species of reptiles, including five species not detected in the previous survey. New species documented on the preserve were the Bullfrog (Lithobates catesbeianus), Eastern Racer (Coluber constrictor), Smooth Green Snake (Liochlorophis vernalis), Redbelly Snake (Storeria occipitomaculata), and Lined Snake (Tropidoclonion lineatum). Smooth Green Snakes represent a new county record, and Redbelly Snakes represent the easternmost published distributional limit for this disjunct population in central Nebraska. Documentation of additional snake species likely reflects a more intensive trapping regime and possibly habitat changes since 1980. Presence of Bullfrogs on Mormon Island probably was linked to excavation of a backwater slough that created a site for overwintering tadpoles. Herein we describe the variable life-history characteristics, habitats, and seasonal activity patterns among these 15 species of herpetofauna on the large river islands. We also discuss how restoration activities and hydrologic changes may influence the presence and abundance of herpetofauna in the region. Understanding the occurrence, habitat use, and seasonality of amphibians and reptiles in this topographically unaltered (i.e., unplowed) reach of river will aid in managing the central Platte River ecosystem to protect and maintain its biological integrity for all organisms.