Modeling wildlife damage to crops and spatio-temporal organization of white -tailed deer during the growing season in northern Indiana

Monica Retamosa, Purdue University

Abstract

I analyzed crop damage data from 100 corn and 60 soybean fields and location data for 10 female and 5 male white-tailed deer from May to October of 2003 and 2004 in Northern Indiana. My first objective was to discriminate the relative influence of local and landscape variables, as well as landscape composition and landscape configuration variables on rate of damage (number of plants damaged/fields's area) to corn and soybean. Rate of crop damage was best predicted by a combination of local and landscape variables. Models with landscape configuration variables were better supported than models with landscape composition variables to explain patterns of corn damage; while the opposite was detected for soybean. Damage to both crop types decreased with field size and distance to the nearest forest patch and increased with amount of field perimeter adjacent to woodlands, amount of woodlands and forest edge and mean forest patch size. My second objective was to compare home range sizes and dispersion of locations (from arithmetic center and from crop fields used by deer) during three consecutive seasons (spring, summer, and early fall) along the crop growing season. Home ranges were smaller and locations were less dispersed from their arithmetic center during summer than during any other season. Locations were less dispersed from crop fields during summer (when damage to crops peaked and plants were in their reproductive non-mature developmental stage) than spring (when plants were in their vegetative stages). Changes in home range sizes and dispersion of locations were likely related to dispersal, reproductive activity and crop phenology. My third objective was to analyze differences in habitat selection according to sex and forest composition. In support of the reproductive hypothesis of sexual segregation, main positive correlates of location for females were area of forest and corridors, whereas main positive correlates of locations for males were area of agriculture and forest. Interspersion of forest patches and mean size of forest patches were 2 of 3 main correlates of a deer's location in more forested and less forested areas, respectively. Resource use was not consistent between sexes or categories of forest composition.

Degree

Ph.D.

Advisors

Rhodes, Purdue University.

Subject Area

Forestry

COinS