The Sloth Invertebrate Ecosystem
Sloths are known to host an entire ecosystem of invertebrate species that are unique to sloth fur. It has been reported that, alongside the symbiotic fungi and algae that act as an effective form of camouflage, up to 950 moths, beetles, cockroaches and even worms can be found on an individual sloth. Unfortunately not everything that is reported is true, especially when it comes to sloths. The Sloth Sanctuary of Costa Rica has rescued over 500 wild sloths, yet has never found a single cockroach or worm living on a sloth. Because of their remarkably low body temperature and unusual circulatory system, sloths do not attract blood-sucking invertebrates such as leeches, fleas, or ticks. Ticks are only ever found on a sloth if it has spent a prolonged period of time on the ground before being brought to the sanctuary.
We wanted to accurately document the invertebrate species that live on sloths surrounding the sanctuary, and in order to do this we collaborated with sloth moth expert Jenny Philips at the National Institute of Biodiversity in Costa Rica. We anaesthetised a sampling of wild sloths and immersed their bodies into airtight collection bags which were sealed around the neck (with the head sticking out!). Gauze pads soaked with the chemical ether were placed inside the bag which effectively anaesthetised all of the invertebrates hiding within the fur. After a few minutes, the sloths were removed from the collection bags and the fur combed through to remove any remaining organisms. The sloths were then brought safely out of the anaesthesia and released back into the forest with tracking devices. This method allowed us to collect the full ecosystem of invertebrates and identify them down to species level. We found each sloth to have an average of 150 sloth moths within the fur, identified as the species Cryptoses choloepi. Only two beetles were recovered and these were identified to be the scarab beetles Uroxys gorgon. No cockroaches, worms, fleas, leeches or ticks were found.