The evolutionary relationships of this unusual canid have yet to be resolved, but research has shown that it is likely to have diverged from the sister-taxon group of maned wolves (Chrysodon) three million years ago (5). Very little is known of the behaviour of this elusive and rare species, as it has proven very difficult to find and observe in the wild. Much of what is known of this species is the result of study of captive populations and anecdotal reports of observations in the wild (4). The bush dog tends to be active in the day, and is associated with water, with most observations of wild individuals being close to or in water courses. At night they retire to a den, which may be an abandoned armadillo nest or inside a fallen tree trunk. Bush dogs live in social groups of up to 12 members (4). They are most often seen hunting in parties of at least two individuals, typically for large rodents including paca (Agouti paca) and agouti (Dasyprocta species) (4) (2). In more open areas, however, it seems that bush dogs hunt alone and take small rodents, teju lizards, snakes and ground-nesting birds (2). There are reports that by hunting in packs, bush dogs are able to tackle prey much larger than themselves, including capybara (Hydrochaeris hydrochaeris) (2). Bush dogs live in extended family groups (4). One alpha female produces offspring; the oestrus cycle is suppressed in other females of the group (4). Gestation takes up to 67 days, after which a litter of one to six pups is produced, though the average litter size is 3.8 pups. The pups are suckled by their mother for around eight weeks. Non-breeding members of the group guard, carry and clean the pups (4) and males bring food to the female in the den (2). The young reach sexual maturity at one year of age. Average life-span is thought to be around ten years (2).