Title

Spatial Ecology, Prey Dynamics, Habitat Modeling, Resource Selection, and Phylogenetic Assessment of the Black Pinesnake

Date of Award

2007

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biological Sciences

First Advisor

Carl Qualls

Advisor Department

Biological Sciences

Abstract

As human-caused species losses approach unprecedented levels, informed biological studies at the landscape, community, organismal, and genetic levels become increasingly important. The six chapters of this dissertation target the black Pinesnake, Pituophis melanoleucus lodingi, an imperiled specialist of the longleaf pine ecosystem, to answer biological questions on all four of these levels. At the landscape level, we sought to identify areas where black Pinesnake populations persist as well as the landscape-level variables driving presence of this secretive taxon. At the community level, we assessed habitat associations of reptile and amphibian communities within the longleaf pine ecosystem, and identified habitat parameters that appear to drive community composition. On a finer scale, we conducted a radio-telemetry study to examine spatial ecology of black Pinesnakes, and to test several hypotheses regarding prey dynamics and resource selection of these snakes. Lastly, we used molecular markers (mitochondrial DNA, i.e. mtDNA) to assess the intraclade relationships of eastern Pituophis, which includes P. m. lodingi, P. m. mugitus, and P. m. melanoleucus, in an attempt to add to existing phylogenetic knowledge of these eastern congeners. Results of our landscape and community-level studies demonstrate the importance of large forested tracts of longleaf pine as well as the importance of frequent fire and low stand densities (low basal areas) to black Pinesnake persistence and restoration. Our radio-telemetry study indicates that these snakes travel great distances, inhabit large home ranges, and frequently cross and suffer mortality from roads. Core home ranges of P. m. lodingi contained significantly more hispid cotton rats than peripheral areas, indicating a correlation between prey availability and movement for these snakes. Results of molecular analysis show a lack of sub-species monophyly within eastern Pituophis, and little geographic structure; however, since there are high levels of morphological and ecological distinction between these three sub-species, future work using alternative molecular markers may clarify these within-clade relationships. By using multiple scales and divergent methods of study, we hope to provide land managers and biologists with the information necessary to conserve and restore P. m. lodingi populations.