Pygmy Three-Toed Sloths

Sloth - Photo by Bryson Voirin

Classified as critically endangered and believed to have a rapidly declining population and habitat area, pygmy three-toed sloths (Bradypus pygmaeus) are native exclusively to the island of Escudo de Veragua, off the Caribbean coast of Panama.

The species is notably smaller than other species of sloths. An adult pygmy three-toed sloth weighs between 5.5 and 7.7 pounds and measures 19 to 21 inches in length. Their external ear canals are conspicuously large. These features are thought to be indicative of a relatively rapid evolution of a new species in an isolated, island habitat. Very little is known about their lifespan.

Pygmy three-toed sloths have been primarily recorded in the red mangrove forests surrounding the island. They mainly feed on mangrove leaves, which puts the population at risk when the mangrove forests are logged.

Ongoing destruction and fragmentation of its habitat, exploitation for food, the presence of feral cats, and lack of sufficient legal protection for pygmy three-toed sloths and their habitat have caused a sharp decrease in its population. While their native island is uninhabited, seasonal visitors, including fishermen, lobster divers, and indigenous people, have been known to hunt the sloths. The sloths’ recent fame has also made them a target for capture and export for public display. An attempt to export eight pygmy sloths by the Dallas World Aquarium in 2013 was thwarted after local environmentalists, police, indigenous groups, and Panamanian authorities negotiated the surrender of the sloths from aquarium representatives. At least two of the captured sloths died prior to release.

The most recent data on these sloths is disheartening, indicating there may be only 48 left—a significant decrease from the last estimate of 79 in 2013. Since 2006, the pygmy three-toed sloth has been listed on the International Union for Conservation of Nature Red List as “critically endangered.” It is not, however, listed as threatened or endangered under the US Endangered Species Act (ESA). In November 2013, AWI petitioned the US Fish and Wildlife Service in November 2013 to have the species listed under the ESA, as such a listing would provide a host of protections, including but not limited to restrictions on take and trade. In June 2014, AWI received a positive 90-day finding on its petition. This finding indicated that listing may be warranted and required the USFWS to issue a final listing determination within 12 months. Although the USFWS originally informed AWI that it expected to make a 12-month finding in fiscal year 2017, this did not occur, and the agency recently indicated that it does not currently have any timeframe for issuing a final determination. This inaction violates the ESA’s statutory mandate, and is likely to result in a further decline in pygmy sloth numbers and increased risk of extinction for the species. AWI may pursue litigation against USFWS to compel the agency to fulfill its legal obligations.

To learn more, see:
USFWS Moving Slow on Sloth Protection and USFWS Warned of Lawsuit for Failing to Protect World’s Smallest Sloth