The Influence of Human Disturbance on the Distribution of Declining Species
This project is an extension of my research on the contraction of the geographic range of threatened and endangered species. In this research I am examining how the spatial distribution of human populations and croplands impacts the geographic range of declining species. Preliminary results suggest that the impact of human disturbances may depend on the abiotic context of the disturbance. Prior research at the local and landscape levels has suggested that roads can negatively impact the biodiversity of a region. No work has examined if the impact of roads extends to larger spatial extents. In a continuation of this research I hope to examine if declining species are able to persist in regions with high road density. 
Range contraction of the red wolf (Canis rufus).
 
Latitudinal Gradient in Species Richness
The latitudinal gradient in species richness is one of the most intriguing ecological patterns that has been described. Most of the taxonomic groups that have been examined show a pattern of decreasing species richness with increasing distance from the equator (latitudinal gradient in species richness). Despite a long history and the numerous hypotheses (>200) that have been presented to describe the pattern, there has been little agreement on what factors contribute to the richness gradient. I hope to test many of these hypotheses using multivariate spatial analyses.
Species richness of New World mammals.
 
Species Distribution Modeling
Species distribution modeling is using the recorded distribution of species (capture localities, and museum or herbarium records) to predict places that the species propably occurs but has not yet been sampled. These techniques represent an objective and repeateable method of describing the geographic range of species. Numerous methods have been suggested for modeling the distributions, but no one technique has emerged as clearly superior to the others. These techniques are valuable in extrapolating the distribution of species for testing hypotheses in biogeography and large-scale ecology or providing insight into the conservation of biodiversity.
Maximum entropy model of the distribution of the American burying beetle (Nicrophorus americanus).
The maximum entropy model of the distribution of the endangered American Burying Beetle (Nicrophorus americanus). Warmer colors represent a higher probability of high quality habitat -- based on historical occurrence data.