Date of Graduation

8-2012

Document Type

Thesis

Degree Name

Master of Science in Biology (MS)

Degree Level

Graduate

Department

Biological Sciences

Advisor/Mentor

Gary R. Huxel

Committee Member

Steven J. Beaupre

Second Committee Member

Steven L. Stephenson

Keywords

Biological sciences, Arkansas, Collared lizard, Ecology, Glade, Habitat, Herpetology, Lizard

Abstract

Loss of suitable habitat is a threat to species worldwide. Habitat destruction, including loss, change, and fragmentation of habitat, is the leading cause of species extinction. Eastern collared lizards (Crotaphytus collaris collaris) are habitat specialists on glades. Both C. c. collaris and glade habitats are rare and of special concern in the state of Arkansas. Many glade populations have already been extirpated in the Ozarks of Arkansas and Missouri. Increasing knowledge of the distribution, habitat structure, and population dynamics of C. c. collaris is important to ensure the survival of this species in Arkansas.

A literature review of the C. c. collaris is presented in Chapter 1. Lizard characteristics, glade habitat characteristics, and information on habitat change, loss, and fragmentation of glades are described. The main goal of my thesis, presented in Chapter 2, was to determine differences across sites in environmental variables, habitat variables, tree community structure, and lizard body condition. I sought to establish differences in these factors in 17 historical C. c. collaris sites (7 with lizard presence and 8 with lizard absence) and determine if the differences were correlated with the presence or absence of C. c. collarispopulations. Significant differences in some factors were found between present sites and absent sites. Environmental variables were not related to the presence or absence of C. c. collaris, indicating a habitat phenomenon rather than environmental. Lizard presence was correlated with habitat structure, as indicated in the ground and canopy cover surveys. Present sites had a positive correlation with rock and soil cover and a negative correlation with CWD, vegetation, and canopy cover; whereas absent sites had a positive correlation with CWD, vegetation, and canopy cover and a negative correlation with rock and soil cover. Present and absent sites had a significant difference in tree community structure. Absent sites had significantly larger trees and a higher frequency of trees compared to present sites. Lizard body condition was associated with the quality and openness of the glade. These data will prove useful in conservation efforts aimed at C. c. collaris recovery in Arkansas and other glade locations in the Ozarks.

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