Comparative Performance Of Landscape-Level Habitat Models For Bobwhite Quail In Illinois
Jennifer J. Dzimiela, Cooperative Wildlife Research Laboratory, Mail Code 6504, Southern Illinois University Carbondale, Carbondale, IL 62901; (618) 453-5495; FAX (618) 453-6944; jennydz@siu.edu
Alan Woolf, Cooperative Wildlife Research Laboratory, Mail Code 6504, Southern Illinois University Carbondale, Carbondale, IL 62901
John R. Roseberry, Cooperative Wildlife Research Laboratory, Mail Code 6504, Southern Illinois University Carbondale, Carbondale, IL 62901
Eric M. Schauber, Cooperative Wildlife Research Laboratory, Mail Code 6504, Southern Illinois University Carbondale, Carbondale, IL 62901
In the past three decades, populations of bobwhite quail (Colinus virginianus) have declined considerably in Illinois and throughout their range. Principal causes of population decline appear to be loss and alteration of habitat due to modern agricultural practices and rural development. Landscape-level habitat modeling can be an efficient method of assessing present amount and distribution of habitat. Two competing bobwhite habitat models have been developed for the state of Illinois. One model categorized 24% (35,000 km2) of Illinois as potentially suitable habitat whereas the other categorized 49% (71,294 km2) of Illinois as potentially suitable habitat. We compare the performance of the two models by testing their habitat categorizations against quail presence/absence data collected within 390 randomly located 250 ha-sample units stratified by model categorization (suitable/unsuitable) and physiographic region. Presence/absence data stem from a mail survey of landowners within sample units. We present comparisons of regional performance variation between the two models throughout Illinois' historic quail range. Also, land use and habitat management data collected in the survey and its potential influence on model performance will be discussed. The goal of this study is to recommend an accurate habitat model for agency use and to help focus upland management activities and concerns to landscapes where they will be the most cost-effective and produce the greatest benefit to quail abundance.