Document Type

Thesis - Open Access

Award Date

2007

Degree Name

Master of Science (MS)

Department

Biology and Microbiology

First Advisor

Charles Dieter

Abstract

The status of jackrabbit (Lepus spp.) populations throughout the Northern Great Plains has been a cause for concern by wildlife managers in recent years and there has been a paucity of information about the ecology of the white-tailed jackrabbit (Lepus townsendii) and the black-tailed jackrabbit (Lepus californicus) in South Dakota. Since there have been little monitoring efforts for hares, 21 permanent spotlight line transects were established across South Dakota for future surveying efforts. These transects were surveyed to obtain baseline information about jackrabbit density and distribution throughout the state. Jackrabbit density was highest in the northwestern portions of the state and lowest in east central South Dakota. The white-tailed jackrabbit was observed throughout the state, but the black-tailed jackrabbit was only confirmed in south central South Dakota. The reproductive biology of white-tailed jackrabbits was evaluated from 314 animals collected in 44 counties throughout South Dakota from June 2004 to September 2005. Jackrabbits were classified into three age classes based on the closure of the proximal epiphysis of the humerus using x-ray analysis. Fluctuations occurred in measured weights of reproductive organs for both sexes which were used to determine annual reproductive activity. The 2005 breeding season began in late February and proceeded until mid July, approximately 142 days, allowing for females to potentially produce 3.3 litters. Breeding synchrony was apparent throughout the breeding season which was determined from the overlap of four periods of estimated conception and parturition dates. Litter size ranged from one to eight, with an average of 4.6 per female. Prenatal mortality from pre-implantation and post-implantation loss was observed to be greatest (32%) in the first littering period in 2005. Capture methods and home range size of white-tailed jackrabbits has received little attention in the literature and has not been reported in South Dakota. We used live traps and a drive corral to compare capture rates of jackrabbits in three selected fields in Brookings, Kingsbury, and Beadle Counties in eastern South Dakota. The Kingsbury and Beadle sites were primarily grazed pastures while the Brookings telemetry site was largely composed of cultivated land. There were 18 white-tailed jackrabbits captured using live traps with an additional 16 captured using the drive corral. We averaged 0.04 jackrabbits per trap night and 0.29 jackrabbits per man-hour using live traps. Using the drive corral, we averaged 1.23 jackrabbits per trap attempt and 0.48 jackrabbits per manhour. The fixed kernel estimator was used to calculate home range size for 25 jackrabbits which ranged from 0.40km2 to 4.76km2. Average female home range size (1.09km2) did not significantly differ from average male home range size (1.34km2).

Description

Includes bibliographical references (pages 98-104)

Format

application/pdf

Number of Pages

166

Publisher

South Dakota State University

Rights

In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/

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