By Nick Paschka
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)
Biogeographic Regions:
neotropical
(native
).
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)
These animals are found in the following types of habitat:
temperate
; tropical
; terrestrial
.
Terrestrial Biomes:
savanna or grassland
; forest
; rainforest
; scrub forest
.
Physical Description
(11 to 15.4 lbs)
(22.64 to 29.53 in)
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)
Some key physical features:
endothermic
; bilateral symmetry
.
Reproduction
Speothos venaticus is most likely a monogamous species.
Mating systems:
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. (Nowak, 1999)
Key reproductive features:
iteroparous
; gonochoric/gonochoristic/dioecious (sexes separate); sexual
; viviparous
.
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)
Key behaviors:
terricolous; diurnal
; motile
; social
; dominance hierarchies
.
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: Negative
N/A
Economic Importance for Humans: Positive
Speothos venaticus possibly play an active role in controlling rodent populations.
Conservation Status
IUCN Red List: [link]:
Vulnerable.
US Federal List: [link]:
No special status.
CITES: [link]:
Appendix I.
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.
Phil Myers (editor), Museum of Zoology, University of Michigan.

