By Darren Naish
Last year the Grzimek’s Animal Life Encyclopedia volume titled Extinct Life appeared in print. I was asked to cover South American mammals, perhaps because they wanted me to write about borhyaenoids, toxodonts, litopterns, astrapotheres and so on (some of which have been covered on Tet Zoo in the past – I really need to get back to those animals some time soon).
However, the article I ended up submitting was devoted to extant species and the conservation issues and extinction risks they face (Naish 2013). For no particular reason, here’s an extract: the part of the carnivoran section devoted to South American canids. Ask over email if you want a pdf of the chapter concerned.
One of the South American region’s most distinctive canids, the Maned wolf Chrysocyon brachyurus, is threatened by many factors (Soler et al. 2005) and is already extinct in Uruguay. Its favored habitat has been reduced by the conversion of land for agriculture. Direct persecution by people, deaths following conflicts with domestic dogs, and collisions with motor vehicles represent serious threats, and the use of its body parts in medicine and ritual also results in the killing of individuals. Conservation interest in this bizarre, omnivorous canid has resulted in legal protection in Brazil and Argentina, but specific action tailored to the ecology of the Maned wolf has yet to be implemented. Significant population declines are expected to occur because of continuing habitat loss and degradation.
The status of another highly distinctive South American canid, the short-limbed Bush dog Speothos venaticus, is difficult to determine because of its natural rarity and elusive, nomadic nature. There are indications, however, that habitat loss and fragmentation, reduction in prey, and domestic dog depredation have resulted in population declines, and the species is also known to be susceptible to diseases transmitted by domestic dogs. Bush dogs are social predators of savannahs and diverse wooded habitats and require healthy populations of small and mid-sized vertebrate prey. The persistence of both Maned wolves and Bush dogs depends on the protection of large, connected areas of grassland, woodland, and shrub-dominated lowland where domestic dogs and vehicle traffic are minimal or absent. The presence of bush dogs in disturbed areas (Oliveira 2009) suggests, however, that they are more adaptable in the face of habitat change than usually thought. [Adjacent photo by Attis.\
The poorly known Short-eared dog Atelocyon microtis is a forest-dependent canid, endemic to western Amazonia. Sleek fur, a streamlined form, and reports of it swimming suggest a semiaquatic lifestyle and reliance on watercourses (Hunter & Barrett 2011). Like other wild canids worldwide, it is known to be at risk from diseases transferred from domestic dogs and also from habitat loss.
Several medium-sized, fox-like canids inhabit South America, including the Crab-eating fox Cerdocyon thous and the zorros (Lycalopex). Some, including the Hoary fox Pseudalopex vetulus, the Pampas fox P. gymnocercus, and the Crab-eating fox, seem tolerant of habitat degradation and remain widespread and common. The Pampas fox, however, is heavily persecuted because of its perceived predation on livestock.
Darwin’s fox P. fulvipes is critically endangered, with two remnant, Chilean populations (one on Chiloé Island) containing fewer than 250 individuals [photo below by Fernando Bórquez Bórquez\. The assumption that Darwin’s fox is a subspecies of the Argentine grey fox or Chilla P. griseus has contributed to a lack of conservation or captive breeding efforts. The two surviving Darwin’s fox populations are relicts, stranded on habitat islands surrounded by agricultural land and, on the mainland, severely at risk from domestic dogs. This species, however, has increasingly been reported from secondary forests, suggesting that – like some of its relatives – it may also be adaptable in the face of habitat change. Its long-term survival perhaps depends on reduced interaction with domestic dogs.