Dispersal of San Joaquin kit foxes, Vulpes macrotis mutica, on Naval Petroleum Reserve No. 1, Kern County, California

Technical Report · Tue Sep 01 04:00:00 EDT 1987

OSTI ID:5589473

Scrivner, J H; O'Farrell, T P; Kato, T T

Between 1980-1986, the movements of 332 pups and 267 adult San Joaquin kit foxes (Vulpes macrotis mutica) were analyzed to determine which animals had dispersed. Of 129 foxes radiocollared as pups and whose parental den ranges were known, 48 (33 males, 15 females) dispersed; about 51% dispersed between July-September, and all but 11 dispersed as pups. There was no sex-specific difference in the average date that dispersal commenced. The number of days between dispersal and death was greater for pups that delayed dispersing until they became adults. Of the 90 radiocollared adults, 23 (14 males, 9 females) dispersed. Adults were found dispersing nearly equally in all months. Foxes less than 1 y old dispersed more frequently than older animals. When dispersal distances of radiocollared pups and adults were combined, no sex-specific differences were found in the average dispersal distance of 4.0 +- 0.5 miles. However, pups dispersed 5.0 +- 0.9 miles, while adults dispersed 3.0 +- 0.5 miles. An adult male traveled 29 miles. No evidence gathered demonstrated that petroleum development activities were responsible for a tendency for more foxes to disperse from developed habitat than from undeveloped habitat. Of the dispersing radiocollared foxes that were recovered dead, 47.9% were killed by predators, 15.1% were killed by vehicles, 1.4% died from other causes, and 35.6% died from unknown causes. These proportions were similar to those observed for nondispersers. 35 refs., 3 figs., 15 tabs.

• Research Organization: EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations
• DOE Contract Number: AC08-83NV10282
• OSTI ID: 5589473
• Report Number(s): EGG-10282-2190; ON: DE88006091
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020900* -- Petroleum-- Environmental Aspects
510500 -- Environment
Terrestrial-- Site Resource & Use Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
AGE DEPENDENCE
ANIMALS
BASELINE ECOLOGY
CALIFORNIA
COMPLIANCE
DISTRIBUTION
ECOLOGY
ECOSYSTEMS
ENDANGERED SPECIES
ENVIRONMENTAL IMPACTS
FEDERAL REGION IX
FOXES
GEOLOGIC DEPOSITS
HABITAT
LAND USE
MAMMALS
MINERAL RESOURCES
MORTALITY
NAVAL PETROLEUM RESERVE
NORTH AMERICA
PETROLEUM DEPOSITS
REGULATIONS
RESERVES
RESOURCE DEVELOPMENT
RESOURCES
SEX DEPENDENCE
SITE CHARACTERIZATION
SPATIAL DISTRIBUTION
TERRESTRIAL ECOSYSTEMS
USA
VERTEBRATES