Can hand-raised sloths be released back into the wild?
An unprecedented number of baby sloths, both the Hoffman’s two-fingered sloth (Choloepus hoffmanni) and the brown throated three-fingered sloth (Bradypus variegatus) are being admitted into rescue centers in Costa Rica.
Although both species of Costa Rican sloths are not considered vulnerable on the IUCN Red List, they are yet recognized to be of conservation concern in Costa Rica, despite a rapid increase in the number of sloths arriving at wildlife rescue facilities.
The main admission causes are the direct outcomes of deforestation – gaps in the canopy which sloths cannot traverse. In the unfortunate, but common, instance where a sloth mother is killed or injured, the baby often survives with non-life-threatening injuries.
We then must turn to wildlife rescue facilities to raise these orphaned or rejected baby sloths. The primary aim of wildlife rehabilitation should always be to return each individual to the wild with maximum chances of survival whenever possible.
However, releasing animals back into the wild is an extremely complex process – coupled with the lack of knowledge on sloths’ ecological needs, wildlife rehabilitation centers are facing issues which can only be solved by further research and a push for sloth conservation initiatives in Costa Rica.
Sloths moms will prepare their babies for life in the jungle by teaching them which leaves are safe to eat, how to carefully navigate the tropical rainforest treetops, and how to avoid predators. You can read the ultimate guide to baby sloths here.
How can we as humans raise a baby sloth with the necessary skills, not only survive but be successful in the wild?
Despite a clear need to determine the most successful methods of raising and rehabilitate sloths, to date, there has been little reliable research into sloth rehabilitation protocols for both babies and adults.
While many aspects of the sloth’s behavior may be innate, certain skills must be learned. This includes knowing which leaves are safe to eat and where to find them, and finding an appropriate habitat.
These are crucial lessons that wildlife rehabilitators must research and overcome to ensure an orphan sloth survives post-release.
The factors contributing to survival post-release are more complex for those sloths that have been orphaned and raised in captivity by humans compared to adult rehabilitated sloths. Adult rehabilitated sloths already have the crucial knowledge required to survive in the jungle.
With the increasing number of sloths arriving at animal rescue centers and the rapidly growing conservation concern for the species, it is becoming imperative that a standard protocol is established which enables organizations to achieve the optimum welfare outcome for each individual!
A release is generally considered to be a success if the animal integrates into the wild breeding population and reproduces.
Although sloths have been hand-reared and set free into wild areas by numerous non-profit organizations and sanctuaries for over a decade, there has been no clear understanding of their fates because post-release monitoring with radio-telemetry has not been a common practice.
The reason for this are multifaceted: there are the logistical problems associated with monitoring a cryptic arboreal species in a dense tropical rainforest, the issue of using electrical equipment in an environment with 90% humidity, and the long process of not only training those to use the equipment efficiently but also the delicate art of sloth-spotting.
The resources required to operate a wildlife rescue center are enormous, and often these resources cannot stretch to post-release monitoring.
Consequently, there is much debate over whether hand-reared sloths can survive in the wild at all with success, with some institutions and shelters choosing to maintain orphan sloths as permanently captive animals to ensure their safety.
To date, no published research studies have been conducted into the success rates of hand-raised baby sloths – however anecdotal evidence suggests that the success and survival rates are alarmingly negative.
Research is not only required into all aspects of raising and releasing baby sloths but there is also no data on the survival and success rates of rehabilitated or relocated adult sloths.
The ultimate goal of all wildlife rescue facilities needs to be to return these individuals back to the location they were rescued, with long-term post-release monitoring.
Post-release monitoring can be grouped into 3 broad data categories: survival, movement, and behavioral data.
While most release efforts that utilize radio-telemetry typically only monitor the length of time an animal can be located in the wild, this can often leave it difficult to determine whether an animal’s death was due to natural causes, or because the animal was not properly prepared for release.
To effectively evaluate the success of a release protocol it is therefore important to combine data on the animal’s movement patterns and post-release behavior with any changes in the overall physical condition of the animal and comparisons with similar data from wild populations.
Here at SloCo we are hopeful that with more research and collaborating with rescue centers, we can give orphaned and injured sloths a much better chance at a successful life in the wild.
We are incredibly excited to be involved in long-term collaborative studies to determine the most appropriate ‘soft-release’ protocols for rehabilitated sloths, and monitor and document the survival of radio-collared hand-reared sloths after being released from rescue centers on the Caribbean coast of Costa Rica.
We will be publishing the results of these sloth projects so that all organizations and individuals working in the rehabilitation of sloths can benefit and learn from the outcome. You can follow and share our progress updates as we post the stories on our blog and social media channels!