Hoffman’s two-toed sloth SSP

Hoffman's sloth with infant. Photo courtesy of Wrylie Guffey, Topeka Zoo.
Hoffman’s sloth with infant. Photo courtesy of Wrylie Guffey, Topeka Zoo.

Hoffman’s two-toed sloths have been exhibited in AZA zoos since 1946. Initial growth of the population was the result of importations, with zoo breeding starting in the mid-1970s. Periodic imports from the private sector continue to occur, although they have been noted to be captive born at those few facilities. Over the past 25 years, the size of the Hoffman’s two-toed sloth population has remained relatively stable, although over the last five years a slight decline (1.2%) has been evident.

According to studbook records, males have reproduced between 1 and 35 years, females between 2 and 29. The oldest animals on record are still living, a male aged approximately 45 and a female aged approximately 37 (both are wild-caught individuals). Infant mortality for the first year of life has been 39% for males and 38% for females. Litter size is usually one offspring.

The current Hoffman’s two-toed Sloth SSP population consists of 73 animals (35 males, 38 females) at 45 AZA institutions. Approximately 5-6 births are necessary to keep the population stable at its current size. The AZA population, which is managed as a Yellow SSP program, had between 1 and 3 birth events per year over the last 10 years (as well as 6 imports total from the private sector). The PAX TAG’s 2009 Regional Collection Plan proposed a target population size of 150 for the Hoffman’s two-toed Sloth population.

As with the Linne’s two-toed sloth, this species can be difficult to sex. Confusion over distinguishing the two two-toed sloth species from one another has also been prevalent. DNA testing is recommended to resolve any remaining species (as well as pedigree) questions– counting neck vertebrae and photo identification are not reliable methods for species determination.

  • Contact the SSP Coordinator for information regarding genetic testing procedures and labs.
  • Please inform the SSP Coordinator/Studbook Keeper of genetic testing results.
  • Institutions wishing to receive (or place animals) should contact the SSP Coordinator for guidance.
  • The SSP can also recommend sources for acquiring sloths. Animals should not be transferred before first discussing with the SSP Coordinator. It must be ensured that the best moves and pairings are carried out in order to achieve demographic stability and genetic health for the population into the future.

After logging into the AZA website, members can view the Breeding and Transfer Plan via the link on the page that follows:

AZA Animal Program: Hoffman’s Two-toed Sloth SSP