SLOTHS

The pygmy sloth is known only from Isla Escudo de Veraguas, in the islands of Bocas del Toro, Panama. Isla Escudo de Veraguas has an area of approximately 4.3 km2 and is about 17.6 km from the mainland of Panama.

This is the smallest of all sloths; adults weigh no more than 3 kg. It has dark gray fur that is darker (and longer) on the shoulder, and agouti gray-brown on the throat. There is a dark midsagittal stripe on the blotchy-colored dorsum. Its tan face bears a dark band across the brow and some orange coloring around the eyes. Longer hair on the crown forms a hood around the short facial hair. Adult males have a black and orange spot (called speculum) between the shoulder blades. The forelimbs bear three digits with large claws and are longer than the hindlegs, which also have three digits. The tail is very short and stumplike.

 

This sloth has only been recorded in the red mangrove forests surrounding the island, currently estimated at 1.3 to 1.5 km2. It has not been recorded from forest patches within the island.

There is no information available on the population status of B. pygmaeus. The population is likely to be relatively small and presumably consists of less than 500 individuals. As far as is known, it primarily, if not exclusively, feeds on mangrove leaves.

Although the island is uninhabited, there are seasonal visitors (fishermen, lobster divers and local people) who are known to opportunistically hunt the sloths. Preliminary studies suggest a low level of genetic diversity among pygmy sloths (Silva et al., 2010; N. Moraes-Barros, pers. comm., 2010), which could lead to endogamic depression if the (already low) population size decreases any further.

The pygmy sloth is listed as Critically Endangered as this species has a very restricted range, being found only on one very small island less than 5 km2 in size, and there is likely a continuing decline in the quality of habitat and area of occupancy due to habitat degradation.
B. pygmaeus is endemic to a single island of Panama, which is protected as a wildlife refuge and is contained within the Comarca Indigenous Reserve. There is a need to improve the enforcement of this protected area, which currently receives little attention from wildlife protection authorities. Conservation of the species could be improved through local awareness programs, specifically those promoting sloths as conservation flagship species.

Additional information and a complete list of references can be found in: Superina, M., T. Plese, N. Moraes-Barros and A.M. Abba (2010): The 2010 Sloth Red List Assessment. Edentata 11(2): 115-134. This article is available here.