Dissertation/Thesis Abstract

Estimating Predator Density and Activity within a Fragmented Landscape
by Kaiser, Jacob, M.S., Southern Illinois University at Edwardsville, 2017, 77; 10686231
Abstract (Summary)

Due to the increasing rate of urbanization and habitat fragmentation, generalist mesopredators are becoming increasingly more abundant. In order to understand how to manage these populations of mesopredators, an understanding of their interspecific relationships along with their activity patterns is necessary. There have been relatively few studies concerning the relationships between mesopredators within their guild and I set out to test whether there is any correlation between the densities of these species and the densities of their prey (small mammals and birds) and whether the raccoon is the main factor influencing these relationships due to its abundance in these areas. I used camera traps across four sites in southwestern Illinois (Sweet William Woods (SWW) on the campus of Southern Illinois University-Edwardsville, a private property in Edwardsville (PP1), John Olin Nature Preserve (JO) in Godfrey, and Pere Marquette State Park (PMSP) in Grafton) and one private property (PP2) site in Missouri to determine the relationship between the densities of members of the mesopredator guild along with their nocturnal activity patterns. Densities were estimated using a random encounter model (REM) that utilizes camera trap capture rates to determine densities for species in which the identity of specific individuals is unknown. Mesopredator surveys were conducted for two months in both spring and summer of 2017. Prey species surveys were conducted for using point count surveys birds and Sherman live traps for small mammals to determine the degree of relationship between densities of prey and predator species. Mesopredators detected were: raccoon ( Procyon lotor), opossum (Didelphis virginiana), coyote (Canis latrans), bobcat (Lynx rufus), red fox (Vulpes vulpes), and grey fox (Urocyon cinereoargenteus). The most common species were raccoon, opossum, coyote, and bobcat. Using a 2-way ANOVA for Site and Season, mesopredator density estimates for each individual species were found not to be significantly different among all five sites (p > 0.05), except raccoon which had a Season effect for Sweet William Woods (SWW) and Site effect with Sweet William Woods being different from Pere Marquette State Park and the two private properties. No correlation was detected using linear correlation between the densities of pairs of the most common mesopredators (p > 0.05). Total summer shrub-nesting avian density differed among the sites with PP1 and PP2 being different and PP1, PP2, and SWW being different from PMSP, and both PMSP and PP2 being different from JO. Small mammal surveys yielded few individuals. No correlation was detected between nest-predators and shrub nesting avian density or diversity (p > 0.05). Raccoons were most active in the time period closest to sunset when seasons were combined and separate. Opossums were equally active across all time periods when seasons were combined and separated. Coyotes were active across all time periods overall and in spring. While none of the relationships between mesopredator densities were significant, this study provides preliminary data that can be compared with future studies to determine if there is a relationship or if these densities vary by season and habitat type.

Indexing (document details)
Advisor: Minchin, Peter R.
Commitee: Essner, Richard, Lee, Danielle N.
School: Southern Illinois University at Edwardsville
Department: Biological Sciences
School Location: United States -- Illinois
Source: MAI 57/02M(E), Masters Abstracts International
Subjects: Ecology, Zoology
Keywords: Camera trap, Mesopredator, Random encounter model
Publication Number: 10686231
ISBN: 978-0-355-60662-1
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