Scientists occasionally discover species as fossils before they are known to still be extant. The coelacanth and the Chacoan peccary are famous examples of this. Add South American bush dogs (Speothos venaticus) to the list. A Danish paleontologist discovered bush dog bones in a Brazilian cave during 1839 and mistakenly thought he’d found evidence of an extinct species. However, bush dogs still exist, though I can’t determine which western scientist first realized they were not extinct. I’m sure native Americans were aware of their existence and may have kept some of them as pets once in a while.
Bush dogs range throughout the tropics from Brazil to Costa Rica. Science was unaware of their existence in Costa Rica until last year, and they are not included in a book I covered on my blog recently–Mammals of Costa Rica by Mark Wainright. Bush dogs are most common in Suriname and Guyana. They prefer lowland tropical forest, wet savannahs, brush, and pasture habitats. They reach a length of 2 feet long and weigh up to 18 pounds. Bush dogs hunt in packs during the day, and their favorite prey are large rodents including pacas, agoutis, and capybaras. The former 2 are uncommon in populated areas where natives hunt them for food, and this explains why bush dogs are also uncommon. Competition with man has likely reduced bush dog numbers over the past 14,000 years. Bush dogs have also been reported attacking peccaries, deer, armadillos, and rheas.
Bush dogs. They may be similar to many species of extinct primitive canids.
Bush dog range map. This map doesn’t include documented sightings with photos taken in Costa Rica last year.
Canids first evolved in North America and were more diverse during the Miocene over 5 million years ago. Cats from Eurasia then invaded the Americas and caused the extinction of many dog genera by outcompeting them. A genetic study determined bush dogs are a sister clade with African hunting dogs (Lycaon pictus). A species of hunting dog occurred in North America during the mid-Pleistocene. Fossils of this species were found in Texas, and it is known as Troxell’s dog (Protocyon texanus). Troxell’s dog also had short legs and dentition that resembled that of bush dogs. This genetic study determined the ancestor of bush dogs diverged from the ancestor of African hunting dogs about 7.5 million years ago. Amazingly, the bush dog’s closest relative lives on the other side of the planet. Another genetic study found bush dogs are more closely related to wolves than they are to raccoon dogs or foxes. However, they are not closely related enough to mate with wolves or domestic dogs and produce fertile offspring.
During the Pleistocene extant bush dogs co-occurred with another species of now extinct bush dog (S. pacivorus). The latter species was slightly larger. More carrion from extinct megafauna supported greater populations of predators then.
Tags: bush dogs, hunting dogs, Speothos, Troxell's dog
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