Ecology of the desert tortoise (Gopherus agassizii) in a desert-grassland community in southern Arizona
AuthorMartin, Brent Errol, 1952-
AdvisorLowe, Charles H.
Krausman, Paul R.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractAfter 6-10 years of mark-recapture observations, I studied seven desert tortoises by radio-telemetry during 1990-1992 in a desert-grassland community in Pinal County, Arizona. Six estimated home-range areas averaged 14.7 ha. Winter-spring (Nov-Jun) use areas (overline x=0.7 ha) were significantly smaller (P = 0.002) than summer-fall (Jul-Oct) use areas (overline x=10.7 ha). A correction formula inflated 1-2 summer-fall use areas of five tortoises 4-41% larger than their corrected home-range areas. Extended movements by females were significantly more frequent (P = 0.0001) than those of males during Mar-Jul, significantly less frequent (P = 0.0057) than males during Aug-Oct, and most frequent by both sexes in September. Use of two slopes and terraces was not season-dependent (P = 0.9159). Tortoises variably used four shelter types (rock, soil burrow, wood rat nest, vegetation), significantly with south-facing entrance aspects (P 0.0005). Hibernaculum structure and location varied. Hibernation ranged from 88-315 days. Radio-equipped tortoises included reuse of mark-recapture locations.
Degree ProgramGraduate College
Renewable natural resources