Geographic Range
Speothos venaticus
is strictly neotropical with a discontinuous range that extends from Panama to the
northern limits of Argentina.
- Biogeographic Regions
- neotropical
Habitat
Speothos venaticus
are found in forests and wet savannas. They are diurnal, inhabiting a den (burrow
or hollow tree trunk) at night. They are semiaquatic and can "dive and swim underwater
with great facility."
- Habitat Regions
- temperate
- tropical
- terrestrial
- Terrestrial Biomes
- savanna or grassland
- forest
- rainforest
- scrub forest
Physical Description
Speothos venaticus
is squat in stature with a body length of 575-750 mm, tail length of 125-150 mm,
and a height of 300 mm. The head is wide, has a short rostrum, and is covered with
short reddish tan fur. The fur darkens to a dark brown or black towards the tail,
and a light patch is found on the underside of the throat (Nowak 1999). The tail
exhibits similar fur as the main body. In addition,
Speothos venaticus
has webbed feet, a diploid chromosome number of 74 (Wayne), and molars of 2/2 pattern
(Hall 1981). In m1 the talonid trenchant and inner cusp (metaconid) are absent (Hall
1981).
- Other Physical Features
- endothermic
- bilateral symmetry
Reproduction
Speothos venaticus is most likely a monogamous species.
- Mating System
- monogamous
Captive observations have indicated that
Speothos venaticus
groups form dominance heirarchies and can exhibit aseasonal reproduction patterns
based on social interactions (Nowak 1999). Estrus usually averages 4.1 days, but
may be suppressed by these interactions. Polyestrus cycles have also been observed.
Estrus reportedly does not begin prior to 10 months of age and until after the pup
is separated from other females and paired with males. The average period between
observed births is roughly 238 days with a gestation period of 67 days. One to six
pups are born with a mean of 3.8 pups which weigh 130-190 g and nurse from 8 weeks
to 5 months.
- Key Reproductive Features
- iteroparous
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
- Parental Investment
- altricial
Lifespan/Longevity
Behavior
Nowak (1999) states that both sexes can cohabitate without quarrels though "a dominance
heirarchy may be established."
Speothos venaticus
creates dens in "burrows or hollow tree trunks," where nursing females remain while
males hunt for their food.
Speothos venaticus
is also highly vocal and has been observed to use high pitched peeps to locate pack
members in forests (Kleiman 1972; Nowak 1999).
- Key Behaviors
- terricolous
- diurnal
- motile
- social
- dominance hierarchies
Communication and Perception
Food Habits
Bush dogs prey mainly on large rodents such as acouchis (genus
Myoprocta
), agoutis (genus
Dasyprocta
), and pacas (genus
Agouti
); they may also prey upon animals of larger mass, such as capybaras (
Hydrochaeris hydrochaeris
) and rheas (
Rheidae
).
- Primary Diet
-
carnivore
- eats terrestrial vertebrates
- Animal Foods
- birds
- mammals
- amphibians
- reptiles
Economic Importance for Humans: Positive
Speothos venaticus possibly play an active role in controlling rodent populations.
Economic Importance for Humans: Negative
N/A
Conservation Status
Speothos venaticus exhibit low density populations. While protected in many countries, their populations are currently diminishing due to habitat destruction. The IUCN Red List rates the species as "Vulnerable" to extinction, because it is becoming divided up into small populations that are separated by unsuitable habitat.
Bush dogs are listed in Appendix I of of the CITES, so international trade in the animals or their products is supposed to be highly regulated.
There are several captive breeding programs at zoos around the world.
Other Comments
Nowak (1999) states that
Speothos venaticus
"was first described from fossils collected in caves in Brazil." While Berta (1984)
"showed that its... affinities lie with other South American canids, especially
Atelocynus
" (cited in Nowak, 1999), recent research utilizing mitochondrial DNA further suggests
that
Speothos venaticus
diverged fairly early from other canids (Wayne, 1993).
Additional Links
Contributors
Nick Paschka (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- monogamous
-
Having one mate at a time.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- social
-
associates with others of its species; forms social groups.
- dominance hierarchies
-
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
- carnivore
-
an animal that mainly eats meat
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
References
Burton, J., V. Burton. 1988. The Collins Guide to the Rare Mammals of the World . Lexington, Massachusetts: The Stephen Greene Press.
Gould, E., G. McKay. 1998. Encyclopedia of Mammals . San Diego: Academic Press.
Hall, E. 1981. The Mammals of North America . New York: John Wiley & Sons.
Kleiman, D. 1972. Social behavior of the maned wolf (*Crysocyon brachyurus*) and bush dog (*Speothos venaticus*): a study in contrast. Journal of Mammalogy , 53: 791-806.
Nowak, R. 1999. Walker's Mammals of the World . Baltimore: The Johns Hopkins University Press.
Thormahlen, M. 199x. "AZA Canid Taxon Advisory Group (TAG)" (On-line). Accessed October 10,1999 at http://members.xoom.com/_XOOM/mthor/dogs .
Thornback, J., M. Jenkins. 1982. The IUCN Mammal Red Data Book. Part 1: Threatened mammalian taxa of the Americas and the Australasian zoogeographic region (excluding Cetacea) . Gland, Switzerland: IUCN.
Wayne, R. 1993. Molecular evolution of the dog family. Trends in Genetics , 9: 218-224.