Graduation Year

2008

Document Type

Dissertation

Degree

Ph.D.

Degree Granting Department

Biology

Major Professor

Earl D. McCoy, Ph.D.

Co-Major Professor

Henry R. Mushinsky, Ph.D.

Keywords

Florida scrub, Metapopulation, Resource selection, Survival, Vertebrate

Abstract

Habitat loss and fragmentation are among the greatest threats to biodiversity, and these threats can be exacerbated or alleviated by the presence of interacting species. The effect of habitat loss and fragmentation on predator-prey systems has received extensive theoretical attention, but empirical studies of these systems yield few clear patterns. I examined the influence of prey abundance and spatial distribution on the foraging ecology and spatial ecology of Masticophis flagellum (Coachwhip) using capture-mark-recapture and radio telemetry techniques. I also examined the influence of saurophagous snake abundance on the survival rate of Sceloporus woodi (Florida Scrub Lizard) populations. Masticophis flagellum positively selected lizard and mammal prey, but within these categories it consumed prey species in proportion to their availability. Masticophis flagellum was vagile and constrained its movements within large home ranges. At all spatial scales examined, M. flagellum strongly selected Florida scrub habitat and avoided wetland habitats. The negative effect of saurophagous snake abundance best explained differences in S. woodi survival rates among patches of Florida scrub. Further loss and fragmentation of Florida scrub habitat will likely have a strong negative impact upon M. flagellum. Because it is precinctive to Florida scrub, Sceloporus woodi will also be negatively affected by the loss of this unique habitat. The potential positive effects of reduced predation pressure from M. flagellum that may accompany loss and fragmentation of Florida scrub is likely to be offset by increased predation rates by habitat and dietary generalist predators that incidentally prey upon S. woodi. Despite the sensitivity of these species to loss and fragmentation of Florida scrub, the prognosis is good for both M. flagellum and S. woodi on relatively large protected sites containing xeric habitats managed with prescribed fire.

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