The impacts of California mule deer fawn health on body condition, survival and hair loss syndrome prevalence

Graduation Date

2016

Document Type

Thesis

Program

Other

Program

Thesis (M.S.)--Humboldt State University, Natural Resources: Wildlife, 2016

Committee Chair Name

Richard Brown

Committee Chair Affiliation

HSU Faculty or Staff

Keywords

Odocoileus hemionus californicus, Hair loss syndrome, Exotic lice, Endoparasites, Ectoparasites, Selenium, Mule deer, Fawns, Body condition, Mortality, Humboldt State University -- Theses -- Natural Resources

Abstract

Mule deer populations are declining throughout California, and in Tuolumne County, California mule deer (Odocoileus hemionus californicus) health is of particular concern. Fawns wintering at Jawbone Ridge have been affected by hair loss syndrome (HLS) since 2009 and carry two species of exotic lice. Our goals were to 1) determine the prevalence of HLS and exotic lice in fawns; 2) experimentally test the association of lice and hair loss; 3) and determine how lice, selenium, and endoparasites influence fawn body condition, overwinter mortality probability, and survival to the age of recruitment. Over three winters 126 fawns were captured and marked, and a subset treated with antiparasitic drugs. During 2010, 2011, and 2012, exotic lice were found on 79 (63%) fawns and 18 (14%) fawns were resighted with HLS in February-May. For every unit increase in the ln (ectoparasite abundance), the probability of hair loss increased by a factor of 1.97. None of three recaptured fawns with HLS had lice. Hair loss was not found to contribute to mortality, and mortality was not impacted by treatment (OR = 0.901). Winter mortality probability was 0.225, 1.63 times higher than summer mortality probability of 0.138 and was influenced by ectoparasite abundance. For every unit increase in the ln(ectoparasite abundance) mortality probability increased by a factor of 1.3. Hair loss does not appear to be an immediate threat to fawn survival. However, lice may pose a greater threat than previously thought, and continued monitoring of exotic lice is warranted in this deer herd.

https://scholarworks.calstate.edu/concern/theses/7w62fb759

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