Alex Figueroa

Abstract

By externally glueing radiotransmitters to the dorsoposterior surface of seven neonate Southern Pacific Rattlesnakes, Crotalus oreganus helleri, I monitored the behavior and ecology of this understudied age-class and species. As an alternative to surgical implantation, external transmitter attachment was less invasive, permitted frequent transmitter replacement, and did not appear to affect neonate behavior. Five neonates tracked through several transmitter replacements (48-125 d) increased 10-38% in mass, indicating successful foraging. Neonates predominately occupied grasslands and coastal sage scrub habitats. Ambush postures were frequently established near rodent features (burrows and runways). Unlike adults, the neonates frequently used arboreal positions (10% of 144 relocations) up to 90 cm above the ground, sometimes assuming ambush postures. Mean daily movements decreased over successive months during the period of study (September 2004-February 2005). Neonates undertook short, nondirectional movements presumably associated with foraging. Schoener's autocorrelation statistics (t2/r2) indicated that many successive snake relocations were time-dependent. Activity ranges and distance measures were positively associated with autocorrelation, suggesting that activity ranges were underestimated when using least-squares crossvalidation (LSCV), the preferred smoothing parameter for fixed kernel estimates. The neonates remained surface-active during the winter, with none overwintering communally. These findings demonstrate that individual snakes can be tracked successfully as neonates and, with further effort, throughout their lifetime. This capacity can one day off er a more complete understanding of a species' natural history and ontogenetic processes.

LLU Discipline

Earth Sciences

Department

Earth and Biological Sciences

School

School of Science and Technology

First Advisor

William K. Hayes

Second Advisor

Ronald Carter

Third Advisor

L. Lee Grismer

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2006

Date (Title Page)

3-2006

Language

English

Library of Congress/MESH Subject Headings

Rattlesnakes -- Research; Animal radio tracking; Snakes -- Ecology; Snakes -- Behavior; Herpetology; Poisonous snakes.

Type

Thesis

Page Count

x; 37

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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