Speothos venaticus (Lund, 1842)

Don E. Wilson & Russell A. Mittermeier, 2009, Canidae, Handbook of the Mammals of the World – Volume 1 Carnivores, Barcelona: Lynx Edicions, pp. 352-446 : 425-426

11.

Bush Dog

Speothos venaticus

French: Chien des buissons / German: Waldhund / Spanish: Zorro vinagre

Other common names: Vinegar Dog, Savannah Dog

Taxonomy. Cynogale venatica Lund, 1842 ,

Minas Gerais, Brazil.

S. pacivorus, an extinct species, is known only from fossil deposits in Lagoa Santa caves in Minas Gerais, Brazil, and may not have existed past the Holocene. Three subspecies are recognized.

Subspecies and Distribution.

S. v. venaticus Lund, 1842 — Argentina (Misiones), Bolivia, N & C Brazil, Colombia, Ecuador, the Guianas, Paraguay, Peru, and Venezuela.

S. v. panamensis Goldman, 1912 — Panama.

S. v. wingei Ihering, 1911 - SE Brazil.

Descriptive notes. Head-body 57- 5-75 cm, tail 12- 5-15 cm; weight 5-8 kg. Characterized by a long body, a short and sometimes stubbytail, and short legs. Broad face with short muzzle, small rounded ears, brown eyes. Head and neck are generally reddishtan or tawny, gradually darkening to black or dark brown hindquarters and legs. The underside is also dark and some individuals may show a pale white throat or chest patch. Coat patterns can be highly variable, from almost all black to very light blonde. Feet are partially webbed and tracks are nearly identical to those of the domestic dog. Bush Dogs are one of three canid species with trenchant heel dentition, a unicuspid talonid on the lower carnassial molar that increases the cutting blade length. Dental formulais13/3,C1/1,PM 4/4, M 2/2 = 40.

Habitat. The Bush Dog is a forest dweller, occurring generally near water sources, particularly small streams, and near available prey populations, especially Lowland Paca (Cuniculus paca). Bush Dogs have been observed in lowland (below 1500 m) forested habitats, including primary and gallery forest, semi-deciduous forest, and seasonally flooded forest. Observations have also been recorded from cerrado habitat in Brazil and Paraguay and pampas (wet savannah) edge/riparian areas, and as far as 5700 m from forest habitat. Occasionally reported from secondary forest, ranchland, and fragmented cerrado ranchland.

Food and Feeding. Primarily carnivorous, Bush Dogs mainly hunt large rodents such as Lowland Pacas and agoutis (Dasyprocta spp.). Their diet often includes other small mammals (e.g. rats, Oryzomys spp. and Proechimys spp., rabbits, Sylvilagus brasiliensis, opossums, Didelphis spp. and the Nine-banded Armadillo Dasypus novemcinctus ). Other prey items include teju lizards (Tupinambis sp.), snakes, and possibly ground-nesting birds. Bush Dogs can engage in group hunting to take prey considerably larger than themselves, such as Capybaras (Hydrochoeris hydrochaeris), and rheas (Rhea americana), deer (Mazama spp.), and even South American Tapir (Tapirus terrestris). Bush Dogs hunt in packs of 2-8 animals (mean 4-5) employing a variety of cooperative hunting strategies. Prey is pursued relentlessly by the pack, even into deep water. In Bolivia the dogs hunt Mazama deer by attacking the legs until the animaltires and falls. Olfaction may play a large role when foraging. Some individuals may enter the burrow of a prey species while other pack members wait at possible escape routes.

Activity patterns. Mostly diurnal; the pair and any family members spend the night in a den.

Movements, Home range and Social organization. Bush Dogs are considered the most social of the small canids, reportedly living in groups ranging from 2-12 individuals, with most observed groups including 2-6 members. The ability of a pack to hunt cooperatively appears to be a primary benefit of the Bush Dog’s social organization. Estimated home range is between 4-6 and 4-7 km *. A monogamous pair-bond is likely with the offspring from multiple yearsliving with the pair. Urine-marking may be important for the formation and maintenance of pair-bonds. Bush Dogs tend to be associated with strong smell, lending evidence that urine is a particularly effective intra-specific communication medium. Males extrude the penis and move laterally, creating a spray rather than a stream, and females drag their ano-genital region over a surface or display either a forelimb handstand or a squat. The raised posture allows urine to be deposited some 150 mm higher than the spray of the male. Adult Bush Dog vocalizations have been classified as whines, repetitive whines, pulsed vocalization, screams, barks, and growls. Infants whine, grunt, growl, and bark; these vocalizations are thought to eitherelicit care or reduce aggression. The elaborate set of close-contact calls assists in communicating subtle changes in mood as well as changes in location.

Breeding. The Bush Dog mating season is unknown, although pups have been found in the wet season. Captive females have two estrous cycles per year. Estrus is aseasonal and likely influenced by social factors. Dominant females appear to suppress the estrus of daughters. Gestation in captivity is 67 days, and meanlitter size is 3-8 (range 1-6). Lactation lasts approximately eight weeks. Males exhibit a high degree of parental care that includes food supplementation to females prior to birth and throughout nursing. Bush dogs appear to be sexually mature by one year.

Status and Conservation. CITES Appendix I. Classified as Near Threatened on The IUCN Red List. Currently, the population is estimated to number fewer than 15,000 mature individuals. Appears naturally rare throughoutits range, independent of human disturbance. Hunting and trade is regulated in Argentina, Bolivia, Brazil, and Venezuela, and is prohibited elsewhere in the range. Perceived threats include habitat conversion and human encroachment. Bush dogs are occasionally killed in Bolivia and Ecuador as predators of chickens, and road kills have been documented in Brazil.

Bibliography. Aquino & Puertas (1997), Beccaceci (1994), Berta (1984), Brady (1981), Cabrera (1961a), Chebez (2008), Defler (1986a), Deutsch (1983), Driwa (1983), Emmons (1998), Gittleman & Harvey (1982), IUCN (2008), Kleiman (1972), Macdonald (1996b), Peres (1991), Porton (1983), Porton et al. (1987), Silveira et al. (1998), Strahl et al. (1992), Van Humbeck & Perez (1998), Zuercher & Villalba (2002), Zuercher et al. (2004).

Figures

8. Dhole (Cuon alpinus), 9. African Wild Dog (Lycaon pictus), 10. Maned Wolf (Chrysocyon brachyurus), 11. Bush Dog (Speothos venaticus), 12. Crab-eating Fox (Cerdocyon thous), 13. Short-eared Dog (Atelocynus macrotis)

Subspecies and Distribution. S. v. venaticus Lund, 1842 — Argentina (Misiones), Bolivia , N & C Brazil , Colombia , Ecuador , the Guianas, Paraguay , Peru , and Venezuela . S. v. panamensis Goldman, 1912 — Panama . S. v. wingei Ihering, 1911 - SE Brazil .