Bush dogs (Speothus venaticus)
The bush dog (image from chesterzoo.org)
Looking more like a small bear or Tasmanian devil than a dog, (or maybe at most a mean looking Dachshund!) the Bush dog is a small, stocky, shy canine that ranges throughout Central and South America. It is incredibly rare to see a Bush dog in the wild, and for a long time after the discovery of fossilised remains in Brazilian caves in 1842, they were believed to be extinct as no one had ever seen one. They are the only members of their genus, Speothus, and genetic data has revealed their closest living relatives are likely to be the Maned Wolf, another, much larger canine from South America, and the African Painted dog. Genetic analysis has revealed 3 subspecies; The Panamanian bush dog (Speothus venaticus panamensis), the South American bush dog (Speothus venaticus venaticus) and the Southern bush dog (Speothus venaticus weijie). They are well adapted for their forest lifestyle, with short, robust limbs, small, rounded ears and dark fur to blend into the shadowed undergrowth of the rainforest.
The known range of the bush dog. Although they can be found throughout this range, their distribution is very patchy. (image from Speothos venaticus (Bush Dog) (iucnredlist.org))
Mystery from the rainforest: the elusive ecology of the Bush dog
Bush dogs are incredibly difficult to study in the wild as they are so rarely seen, and in fact a lot of the information provided to researchers comes from indigenous tribes in the Amazon basin. A team of researchers who have been camera trapping a ranch in Brazil since 2013 only caught footage of Bush dogs in 2020. It can be difficult to locate bush dogs to study them, and it can be incredibly stressful for the animals to be captured and tagged. Non-invasive techniques are often used instead, relying on the genetic analyses of scats and detection dogs to confirm the presence of bush dogs, and using geographic information systems to plot the ranges and habitat use of the dogs. This provides more accurate estimates of population density than the use of camera traps or opportunistic sightings in the field. The genetic analysis of scat is particularly useful, as it can even detect one individual from another; all from a scoop of dog poop!
They are reported to be habitat generalists, although they are always located close to a water source. They have been reported in pampas (wet savannahs), the Cerrado (a huge tropical savannah in Brazil), Caatinga (a region of semi-arid topical vegetation), Gran Chaco (a hot, semiarid lowland basin region across Bolivia, Paraguay and Argentina) and even mangroves along the coast. They are also occasionally reported in ranch lands and other disturbed or fragmented areas. They are quite unusual among canines in that they live a semi aquatic life, evidenced by their webbed feet. They are reported to drive they prey into the water, and Indian hunters have told researchers that they have witnessed part of a pack forcing a paca into the water, whilst the rest of the pack waits on the opposite bank to ambush the unfortunate animal. In captivity they are known to spend a lot of time swimming and playing in the water.
Studies from captivity have shown that bush dogs live in large family groups with pups from several litters, although studies in the wild have recorded solitary individuals across their range. Packs are made up of a mated pair and their relations, although only the adult pair breed, and the other subordinate members of the pack help raise and protect the pups. As they frequently hunt in areas with dense vegetation, packs keep in contact through a repertoire of vocal calls and whines. Packs predominantly hunt agoutis, pacas, and armadillos, with other small mammals, birds and fruit less common in their diet. Studies have shown they have different dietary preferences depending on the region they are found in. They hunt cooperatively, allowing them to take down prey much larger than them. Local tribesmen have even reported that Bush dogs are capable of taking down a deer, quite an impressive feat for such short, stocky little dogs!
A shrinking world: threats facing the Bush dog
The IUCN currently lists the Bush dog as near threatened, although it is particularly difficult to get a good idea of population numbers in the wild, although most researchers agree they are in decline, in large part caused by a rapidly shrinking habitat.
South America is facing unprecedented levels of deforestation; between 2010 and 2020, South America lost on average 2.6 million hectares of forest each year. This threatens bush dog habitat and also reduces the amount of available prey. This is a particular concern for Bush dogs, as telemetry studies conducted on a pack in 2012 revealed that they prefer large areas of uninterrupted habitat as they move around between seasons and patchy habitat could put the canines at risk of conflict with humans. 80% of recorded sightings of bush dogs are in pristine, uninterrupted habitat and although they can live and hunt in human disturbed areas, further research revealed that the more fragmented a habitat is, the larger an area is required for the pack. In addition, reducing habitat can bring Bush dogs into closer proximity with humans, driving conflict and increasing the risk of disease transmitted from domestic dogs, such as the often-fatal canid disease Parvovirus or canine distemper virus. There have been recorded outbreaks of disease such as Campylobacter driven haemorrhagic enteritis, when 13 of 15 individuals in a pack died very quickly once they were exposed to an infected coati they fed upon. This shows the susceptibility of bush dogs to diseases, and with the risk of increasing human interaction, conservationists are considering vaccinating bush dogs against some of the more common canine pathogens.
Bush dogs are naturally rare, but their patchy distribution and low numbers put them at massive risk of further population declines. Unfortunately, in most parts of their range, there are simply not enough resources or infrastructure to conserve the bush dog.
Conservation Optimism
Conservation of bush dog habitat is perhaps the most important action that will protect the future of the species, but it is nigh on impossible for scientists to determine where they live. As mentioned before, another canine has been recruited into the fight to save the bush dog. Scent detecting dogs are able to detect burrows and trails that bush dogs use without disturbing them with invasive surveys. More research is ongoing to improve the way scent detecting dogs are used, not just for bush dogs but for other species too.
A scent detection dog hard at work locating bush dog dens in the Amazon basin. (image from How Do Dogs Help With Bush Dog Conservation? – The Wolf Center)
Bush dogs are held in captivity in many zoos globally and are part of a successful breeding programme across Japan, Europe, Brazil and North America. So far, these breeding programmes haven’t attempted to reintroduce any animals into the wild, but for the time being, with the state of habitat loss as it is, they are probably safer in captivity for the time being.
The Canid specialist group, part of the IUCN, work to research canid species and figure out the best ways to conserve them in the wild and captivity. They have a range of goals;
- raise funding for canid research globally and particularly in threatened areas.
- Improve the management of troublesome species and help to mitigate human wildlife conflict.
- Guide governments and organisations on best conservation practices.
You can check out the active projects they have at Projects | Canids.
Awesome videos!
References
Aquino, R. and Puertas, P. (1997) ‘Observations of Speothus venaticus (Canidae: Carnivora) in its natural habitat in Peruvian Amazonia.’ Zeitschrift für Säugetierkunde.
DeMatteo, K.E. (2008) ‘Using a survey of carnivore conservationists to gain insight into the ecology and conservation status of the bush dog.’ Canid News.
De, Matteo, K.E. Rinas, M.A. Argüelles, C.F. Zurano, J.P. Selleski, N. Di Betetti, M.S. and Eggert, L.S. (2014) ‘Noninvasive techniques provide novel insights for the elusive bush dog (Speothos venaticus).’ Wildlife Society Bulletin.
De Mello Beisiegel, B. and Ades, C. (2002) ‘The behaviour of the Bush Dog (Speothus venaticus Lund, 1842) in the field: a review.’ Revista de Etologia.
DeSouza Lima, E. Jorge, R.S.P. and Dalponte, J.C. (2009) ‘Habitat use and diet of bush dogs, Speothos venaticus, in the Northern Pantanal, Mato Grosso, Brazil.’ De Gruyter.
Speothos venaticus (Bush Dog) (iucnredlist.org)
How Do Dogs Help With Bush Dog Conservation? – The Wolf Center
Lima, E.S. Jorge, M.L.S.P. Jorge, R.S.P. and Morato, R.G. (2014) ‘The bush dog Speothus venaticus: area requirement and habitat use in cultivated lands.’ Oryx.
Nyakatura, K. and Bininda-Emonds, O.R.P. (2012) ‘Updating the evolutionary history of Carnivora (Mammalia): a new species-level supertree complete with divergence time estimates.’ BMC Biology.
Romo, V. (2020) ‘Illegal deforestation rises in South America’s indigenous territories, parks.’ Mongabay
