Date of Award

Spring 5-7-2019

Document Type

Thesis

Degree Name

Master of Science in Fisheries and Wildlife Science

College

College of Natural & Health Sciences

Department

Biological Sciences

Committee Chair

Dr. Thomas Nupp

Second Committee Member

Dr. Jorista Garrie

Third Committee Member

Dr. Christopher Kellner

Dean of Graduate College

Dr. Jeff Robertson

Abstract

The American burying beetle (Nicrophorus americanus, hereafter ABB) was listed as an endangered species in 1989 and many hypotheses have been developed to explain their rangewide decline. I investigated the carcass competition hypothesis that implicates increased competition between vertebrate scavengers and ABBs for appropriate-sized carcasses as a cause for ABB decline. Predators of medium size that occupy an intermediate trophic level (hereafter mesopredators) are potential competitors for carcasses. I used camera trapping to assess mesopredator abundances in nine different habitats at Fort Chaffee Joint Maneuver Training Center (FCJMTC) in western Arkansas because this area supports the largest known population of ABBs in the state. In part one of the study, I examined mesopredator presence at random locations over two field seasons and captured photos of Virginia opossum, northern raccoon, coyote and bobcat activity over 2,076 trap nights. Coyotes were the most captured mesopredator at 60 independent sightings followed by northern raccoons (37 sightings), bobcats (12 sightings) and Virginia opossums (11 sightings). A random encounter model was used to obtain mesopredator density estimates and identify potential correlations between mesopredator and ABB abundances. Density estimates were highest for mesopredators in the bottomland hardwood and deciduous habitats while ABBs are most abundant in grassland/ prairie and oak habitats. A negative relationship was seen between mesopredator counts per 100 trap nights and distance to the edge of the base (estimate = -0.0006, SE = 0.0002, p= 0.003) whereas ABBs are found in the central area of the base. In part two of the study, I examined mesopredator presence at sites in conjunction with yearly ABB trapping efforts. I captured 117 independent animal sightings at 72 sites over two seasons and 216 trap nights. Commonly captured mesopredators included Virginia opossums, northern raccoons, coyotes and bobcats, which made up 55% of all animal sightings. vii Virginia opossums were the most captured mesopredator at 48 independent sightings followed by northern raccoons, coyotes and bobcats at 9, 4 and 3 independent sightings respectively. A high ABB capture zone was determined from the ABB census data and a Wilcoxon Rank Sum test was conducted between sites inside and outside the high ABB zone and mesopredators per trap day counts. When the seasons were combined there were significantly more mesopredator captures outside of the ABB areas compared to within the high ABB areas (W=409, P

Share

COinS