Speothos venaticusbush dog

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Geographic Range

Speothos venaticus is strictly neotropical with a discontinuous range that extends from Panama to the northern limits of Argentina. (Hall, 1981; Nowak, 1999; Thornback and Jenkins, 1982)

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." (Nowak, 1999)

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). (Burton and Burton, 1988; Hall, 1981; Nowak, 1999; Wayne, 1993)

  • Range mass
    5 to 7 kg
    11.01 to 15.42 lb
  • Range length
    575 to 750 mm
    22.64 to 29.53 in

Reproduction

Speothos venaticus is most likely a monogamous species.

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. (Nowak, 1999)

  • Range number of offspring
    1 to 6
  • Average number of offspring
    3.8
  • Average number of offspring
    4
    AnAge
  • Range gestation period
    65 to 70 days
  • Range weaning age
    28 to 150 days
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    304 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    365 days
    AnAge

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). (Kleiman, 1972; Nowak, 1999)

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 (Hydrochoerus hydrochaeris) and rheas (Rheidae). (Burton and Burton, 1988; Nowak, 1999)

  • 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. (Burton and Burton, 1988; Nowak, 1999; Thornback and Jenkins, 1982)

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). (Nowak, 1999; Wayne, 1993)

Contributors

Nick Paschka (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

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.

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

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.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

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).

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

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.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

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).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

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.

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

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.