Download Vulpes macrotis kit fox

Vulpes macrotis
kit fox
By Allen Patton
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Carnivora
Suborder: Caniformia
Family: Canidae
Genus: Vulpes
Species: Vulpes macrotis
Geographic Range
Kit foxes are primarily found in the southwestern part of the United States and northern
and central Mexico. They are found as far north as the arid interior of Oregon, east to
southwestern Colorado, south through Nevada, Utah, southeastern California, Arizona,
New Mexico, and into western Texas. In Mexico they are found mainly in the states of
Coahuila, Chihuahua, and Nuevo Leon, and throughout Baja California. ("Kit Fox
(Vulpes macrotis): A Technical Conservation Assessment", 2006; List and Cypher,
2005)
Habitat
Elevation
400 to 1900 m
(1312 to 6232 ft)
Kit foxes are primarily found in arid regions, such as desert scrub, chaparral, and
grasslands. Vegetation communities vary with the regional aridland fauna, but some
examples of common habitats are saltbrush Atriplex polycarpa and sagebrush Artemisia
tridentata. Kit foxes may also occur in agricultural areas and urban environments. They
occur at elevations of 400 to 1900 meters. Kit foxes prefer areas with loose soils for
constructing dens. They spend most of their time in dens that they dig themselves or
take over from prairie dogs (Cynomys), other rodents, and American badgers (Taxidea
taxus). Kit foxes occupy dens year-round and have several dens in their territory that
they rotate among. Dens could have one or many entrances and are usually covered by
thick brush. They usually stay in their dens during the daytime, exiting to hunt for food
at night. ("Kit Fox (Vulpes macrotis)", 1993; "Kit Fox (Vulpes macrotis): A Technical
Conservation Assessment", 2006; List and Cypher, 2005)
Physical Description
Mass
1.60 to 2.70 kg
(3.52 to 5.94 lbs)
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Length
455 to 535 mm
(17.91 to 21.06 in)
Kit foxes are the smallest member of the family Canidae in North America. Their most
distinctive feature is their exceptionally large ears placed close together on the head.
The ears are from 71 to 95 mm in height and they play a role in dissipating heat and the
excellent hearing of kit foxes. ("Kit Fox (Vulpes macrotis)", 1993; List and Cypher,
2005)
Kit foxes range in color from yellowish to gray. They usually have a dark-colored back,
light-colored undersides and inner ears, and distinct dark patches on each side of the
nose and at the end of the tail. Males average slightly larger than females. Head and
body length is from 485 to 520 mm in males (average 537) and from 455 to 535 mm in
females (average 501). The tail is from 250 to 340 mm long. Males average 2.29 kg and
females 1.9 kg, ranging from 1.6 to 2.7 kg. ("Kit Fox (Vulpes macrotis)", 1993; List and
Cypher, 2005)
Reproduction
Breeding interval
Kit foxes breed once yearly.
Breeding season
Breeding occurs from December to February.
Number of offspring
1 to 7; avg. 4
Gestation period
49 to 55 days
Time to weaning
8 weeks (average)
Time to independence
5 to 6 months
Age at sexual or reproductive maturity (female)
10 months (low)
Age at sexual or reproductive maturity (male)
10 months (low)
Most studies have shown kit foxes to be monogamous, with pairs mating for life.
Occasional polygyny has also been reported. When the female is ready to reproduce,
she goes out on her own in search of a den. This usually happens around the month of
September. In October, the male kit fox will join her and remain with her until the end
of the breeding season. Female young will sometimes delay dispersal and stay an
additional year beyond their independence to help raise their siblings. ("Kit Fox (Vulpes
macrotis): A Technical Conservation Assessment", 2006; List and Cypher, 2005)
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Kit foxes mate once per year from mid-December to February. The typical gestation
period is 49 to 55 days, and they can produce a litter of 1 to 7 pups, with an average of
4. Births occus from February to mid-March. Although females are able to breed 10
months after birth, many females do not reproduce that first year. Young females are
much lower reproductive success than do older females. ("Kit Fox (Vulpes macrotis)",
1993; "Kit Fox (Vulpes macrotis): A Technical Conservation Assessment", 2006; List
and Cypher, 2005)
Young stay in their birth den until they are 4 weeks old and are weaned at 8 weeks old.
The young begin to hunt with their parents at 3 to 4 months old and are independent at 5
to 6 months old. Most young disperse by 8 months old. Both male and female parents
care for and protect their young. ("Kit Fox (Vulpes macrotis): A Technical Conservation
Assessment", 2006; List and Cypher, 2005)
Lifespan/Longevity
Extreme lifespan (wild)
7 years (high)
Extreme lifespan (captivity)
12 years (high)
Average lifespan (wild)
5.50 years
Vulpes macrotis survival rates are dependent on food availability, reproduction, and
local predators. Different studies have estimated different life expectancies for kit foxes.
Some report lifespans of 3 to 4 years, while others reported 7 to 12 years. In California a
study of 144 kit fox pups showed a 74% mortality rate in pups within the first year.
("Kit Fox (Vulpes macrotis): A Technical Conservation Assessment", 2006)
Behavior
Territory Size
2.50 to 11.60 km^2; avg. 3.22 km^2
Kit foxes remain relatively inactive during hot desert days, remaining in their dens.
They are primarily nocturnal but occasionally are crepuscular as well. Kit foxes forage
alone. Kit foxes are not exceptionally territorial, preferring to live in underground
burrows in pairs or small family groups. Territories of neighboring family groups can
overlap. Females are thought to be relatively sedentary, males seem to disperse more
widely. ("Kit Fox (Vulpes macrotis)", 1993; Arjo, Bennett, and Kozlowski, 2003; List
and Cypher, 2005)
Home Range
Home range size of Vulpes macrotis is typically 3.22 square kilometers, in which up to
3 individuals may inhabit. Home range sizes vary from 2.4 to 11.6 square kilometers.
("Kit Fox (Vulpes macrotis)", 1993; Koopman, Cypher, and Scrivner, 2000; List and
Cypher, 2005; McCue and O'Farrell, 1992)
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Communication and Perception
Kit foxes have very large ears and excellent hearing. Kit foxes sometimes bark at
perceived threats or use a "hacking growl" in intraspecific encounters. ("Kit Fox
(Vulpes macrotis)", 1993; "Kit Fox (Vulpes macrotis): A Technical Conservation
Assessment", 2006; Ralls and White, 2003)
Food Habits
Kit foxes eat primarily rodents and rabbits. Species preyed on varies regionally, but the
most common prey are prairie dogs (Cynomys species), kangaroo rats (Dipodomys
species), black-tailed jackrabbits (Lepus californicus), and cottontail rabbits (Sylvilagus
species). Kit foxes are primarily carnivores, but if food is scarce, they have been
reported to eat tomatoes (Lycopersicon esculentum), cactus fruits (Carnegiea gigantea),
and other available fruits. They also will scavenge carrion and eat large insects, lizards,
snakes, and ground-dwelling birds. ("Kit Fox (Vulpes macrotis): A Technical
Conservation Assessment", 2006; George Jr., 1990; Henbest et al., 1989; List and
Cypher, 2005)
Kit foxes may compete for food and dens with coyotes (Canis latrans), bobcats (Lynx
rufus), red foxes (Vulpes vulpes), and American badgers (Taxidea taxus). (List and
Cypher, 2005)
Predation
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Known predators
coyotes (Canis latrans)
bobcats (Lynx rufus)
humans (Homo sapiens)
red foxes (Vulpes vulpes)
American badgers (Taxidea taxus)
feral dogs (Canis lupus familiaris)
large raptors (Accipitridae)
Predation by coyotes (Canis latrans) accounts for over 75% of kit fox predation. Other
predators include bobcats (Lynx rufus), red foxes (Vulpes vulpes), American badgers
(Taxidea taxus), feral dogs (Canis lupus familiaris), and large raptors (Accipitridae).
Also kit fox deaths have been due to interactions with humans, such as illegal hunting
and trapping for fur. Kit foxes are also hit by cars. Kit foxes are wary and nocturnal,
with cryptic coloration, reducing their risk of predation. ("Mortality of San Joquin Kit
Fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training Site and
California", 1992)
Ecosystem Roles
Kit foxes are prey for other carnivores such as coyotes (Canis latrans) and bobcats
(Lynx rufus). Also kit foxes are predators of rodents or other small animals, including
black-tailed jackrabbits (Lepus californicus), kangaroo rats (Dipodomys), and prairie
dogs (Cynomys). Because kit foxes move from den to den in search of a mate and food,
their old dens are taken over by other kit foxes or other animals. As scavengers, kit
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foxes also play a major role in biodegradation. ("Kit Fox (Vulpes macrotis)", 1993; "Kit
Fox (Vulpes macrotis): A Technical Conservation Assessment", 2006; "Mortality of
San Joquin Kit Fox (Vulpes velox macrotis) at Camp Roberts Army National Guard
Training Site and California", 1992; Egoscue, 1956; Harrison, Patrick, and Schmitt,
2002; Voge, 1955; Wilson and Bishop, 1966)
Fleas, such as Pulex irritans and Pulex simulans, are common parasites of this species.
Ticks are also common and include Ixodes texanus and Dermacentor perumapertus.
Other cestode parasites include Mesocestoides corti, Mesogyna hypatica, and
Dipylidium caninum. Unidentified roundworms and tapeworms have been noted from
scat collections.
Commensal or parasitic species (or larger taxonomic groups) that use this species
as a host

fleas (Pulex irritans)

fleas (Pulex simulans)

cestode parasites (Mesocestoides corti)
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cestode parasites (Mesogyna hypatica)

cestode parasites (Dipylidium caninum)

ticks (Ixodes texanus)

ticks (Dermacentor perumapertus)
Economic Importance for Humans: Negative
Kit foxes can have a negative impact on humans by carrying diseases. The main disease
of concern is plague, which foxes contract from fleas. (Harrison, Patrick, and Schmitt,
2002)
Ways that these animals might be a problem for humans:
injures humans (carries human disease); causes or carries domestic animal disease
Economic Importance for Humans: Positive
Kit foxes are important members of native ecosystems, helping to control rodent
populations through predation. ("Kit Fox (Vulpes macrotis): A Technical Conservation
Assessment", 2006)
Ways that people benefit from these animals:
research and education; controls pest population.
Conservation Status
IUCN Red List:
Not Evaluated.
US Federal List:
Endangered.
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.
CITES:
No special status.
Kit foxes are listed as "Least Concern" on the IUCN red list of threatened species.
Populations throughout most of the United States are estimated to be stable. San
Joaquin kit foxes, V. macrotis mutica, are considered endangered in the United States,
as their habitat continues to be fragmented and lost to agriculture. Kit foxes are listed as
species of concern in some states, including Colorado and Utah, where programs exist
that are designed to protect kit fox populations. They are considered state threatened in
California and state endangered in Oregon. In Mexico it is likely that kit fox populations
are in decline as 40% of prairie dog populations have been converted to agriculture
since 1994. Kit foxes are considered "vulnerable" in Mexico. ("Kit Fox (Vulpes
macrotis)", 1993)
Other Comments
Biologists sometimes gather information on the overall health of kit foxes Vulpes
macrotis by gathering serum chemistry values. (Koopman, Cypher, and Scrivner, 2000;
McCue and O'Farrell, 1992)
Other common names include: desert fox, zorra del desierto, zorra norteña (Spanish),
and wüstenfuchs (German). (List and Cypher, 2005)
Contributors
Tanya Dewey (editor), Animal Diversity Web, University of Michigan Museum of
Zoology.
Allen Patton (author), Radford University. Karen Francl (editor, instructor), Radford
University.
References
Utah State University Wildlife Management: Jensen E., Poulsen C., Rogers M.,
Messmer Dr. T.. Kit Fox (Vulpes macrotis). Wildlife Notebook Series No. 9. Logan,
Utah: Department of Fisheries and Wildlife. 1993.
Denver Museum of Nature and Science and Meaney & Company, Bear Canyon
Consulting, Wyoming Natural Diversity Database: Meaney Dr. C. A., Reed-Eckert M.,
Beauvais Dr. G. P.. Kit Fox (Vulpes macrotis): A Technical Conservation Assessment.
DE-AC08-88NV10617. Rocky Mountain Region: USDA Forest Service, Rocky
Mountain Region, Species Conservation Project. 2006.
U.S. Departments of the Army and Air Force National Guard Bureau. Mortality of San
Joquin Kit Fox (Vulpes velox macrotis) at Camp Roberts Army National Guard
Training Site, California. DE-AC08-88NV10617. Nevada Field Office: U.S.
Department of Energy. 1992.
Arjo, W., T. Bennett, A. Kozlowski. 2003. Characteristics of current and historical kit
fox (Vulpes macrotis) dens in the Great Basin Desert. Canadian Journal of Zoology, 81:
96-102.
Egoscue, H. 1956. Preliminary Studies of the Kit Fox in Utah. Journal of Mammalogy,
37/3: 351-357.
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George Jr., W. 1990. Tomato. Pp. "325-326" in S. Fetzer Company, ed. The World Book
Encyclopedia, Vol. 19, First Edition. Chicago London Sydney Toronto: Scott Fetzer
Company.
Harrison, R., M. Patrick, C. Schmitt. 2002. Foxes, Fleas, and Plague in New Mexico.
The Southwestern Naturalist, 48/4: "720-728".
Couper, H., D. Dixon, D. Fuller, J. Garlick, J. Griffiths, N. Henbest, B. Jones, R.
Kerrod, A. Lyons, R. Matthews, R. Mills, Z. Vrbova. 1989. Deserts. Pp. "98" in R.
Kerrod, ed. The Plant World, Vol. 5, First Edition. Chicago: Bull Publishing.
Koopman, M., B. Cypher, J. Scrivner. 2000. Dispersal Patterns of San Joaquin Kit
Foxes (Vulpes macrotis mutica). Journal of Mammalogy, 81/1: "213-222".
List, R., B. Cypher. 2005. "Vulpes macrotis (kit fox)" (On-line). IUCN Canid Specialist
Group. Accessed April 05, 2008 at
http://www.canids.org/species/Vulpes_macrotis.htm.
McCue, P., T. O'Farrell. 1992. Serum Chemistry Values of the Endangered San Joaquin
Kit Fox (Vulpes macrotis mutica). Journal of Wildlife Diseases, 28/3: 414-418.
Haight, R., B. Cypher, P. Kelly, S. Phillips, K. Ralls, H. Possingham. 2004. Optimizing
Reserve Expansion for Disjunct Populations of San Joaquin Kit Fox. Biological
Conservation, 117: "61-72".
Ralls, K., P. White. 2003. Diurnal Spacing Patterns in Kit Foxes, a Monogamous Canid.
The Southwestern Naturalist, 48/3: "432-436".
Voge, M. 1955. A List of Cestode Parasites From California Mammals. American
Midland Naturalist, 54/2: 413-417.
Smith, D., K. Ralls, B. Cypher, H. Clark, Jr., P. Kelly, D. Williams, J. Maldonado.
2006. Relative Abundance of Endangered San Joaquin Kit Foxes (Vulpes macrotis
mutica) Based on Scat-Detection Dog Surveys. The Southwestern Naturalist, 51/2:
"210-219".
Wilson, N., P. Bishop. 1966. A New Host and Range Extensino for Pulex simulans
Baker with a Summary of Published Records (Siphonaptera: Pulicidae). American
Midland Naturalist, 75/1: 245-248.
2009/03/01 10:19:57.768 US/Eastern
To cite this page: Patton, A. and K. Francl. 2008. "Vulpes macrotis" (On-line), Animal
Diversity Web. Accessed March 02, 2009 at
http://animaldiversity.ummz.umich.edu/site/accounts/information/Vulpes_macrotis.html
University of Michigan Museum of Zoology.
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