Duane Diefenbach, PhD (Former Employee)

Recreational hunting is crucial for controlling white-tailed deer populations. Public land is increasingly important as access to private lands declines. However, differences between public and private land hunters remain unknown. Our study of Pennsylvania hunters revealed differences between private and public land hunters that may pose problems for management. Hunters who only hunted...

Dispersal distances and their distribution pattern are important to understanding such phenomena as disease spread and gene flow, but oftentimes dispersal characteristics are modeled as a fixed trait for a given species. We found that dispersal distributions differ for spring and autumn dispersals of yearling male white-tailed deer (Odocoileus virginianus) but that combined data can be...

Several bird-survey methods have been proposed that provide an estimated detection probability so that bird-count statistics can be used to estimate bird abundance. However, some of these estimators adjust counts of birds observed by the probability that a bird is detected and assume that all birds are available to be detected at the time of the survey. We marked male Henslow's Sparrows

The spacing patterns and mating systems of solitary carnivores have important implications for social behavior and for the survival and reproduction of individuals. Over 2 years, we reintroduced 32 (15 males and 17 females) bobcats (Lynx rufus) to a barrier island off the coast of Georgia and studied patterns of bobcat spatial distribution. Population density increased to 3.1 bobcats/10...

Increased use of stable isotope analysis to examine food-web dynamics, migration, transfer of nutrients, and behavior will likely result in expansion of stable isotope studies investigating human-induced global changes. Recent elevation of atmospheric CO2 concentration, related primarily to fossil fuel combustion, has reduced atmospheric CO2 ??13C (13C/12C), and this change in isotopic...

Animal dispersal patterns influence gene flow, disease spread, population dynamics, spread of invasive species, and establishment of rare or endangered species. Although differences in dispersal distances among taxa have been reported, few studies have described plasticity of dispersal distance among populations of a single species. In 2002-2003, we radiomarked 308 juvenile (7- to 10...