An evaluation of beaver habitat models for Illinois rivers

Abstract

Beavers (Castor canadensis) are agents of landscape change, altering the structure and species composition of vegetative communities through herbivory and water impoundment. To better manage beavers in Illinois, improved methods of monitoring riverine populations of this species are needed. The objectives of the study were to (1) locate, map and quantify the spatial distribution of beaver colonies along the Embarras River, (2) test the efficacy of 2 existing beaver habitat models, the U.S. Fish and Wildlife Service's Habitat Suitability Index (HSI) model and Missouri's beaver habitat model, for predicting the relative density of beavers and (3) develop a new multiple regression habitat model for predicting the density of beavers in Illinois' riverine habitats. The Embarras River, in east-central Illinois, was partitioned along its length into 3 ecological divisions. Each division was divided into 25-km sections, and then each section was subdivided into 10 2.5-km segments. Two segments in each section were randomly selected and surveyed. This resulted in a total of 26 2.5-km segments of the river in which the number of beaver colonies (dependent variable) and the set of habitat variables (independent variables) were quantified during November 2001 to September 2002.

Date of Award	2005
Original language	American English
Awarding Institution	Eastern Illinois University
Supervisor	Thomas Nelson (Supervisor)