A variety of jungle animals all use one type of tree as a latrine

A host of tree mammal species, including opossums, two-toed sloths and wild cats, have been found sharing a latrine in the forest canopy.

Jeremy Quirós-Navarro, an independent ecologist in Costa Rica at the time, first discovered a latrine 30 metres up a strangler fig tree while looking for somewhere flat to place a camera. He saw a natural platform, strewn with different colours and textures of faeces. Later, he noticed more latrines, always on the same species: Ficus tuerckheimii.  

Quirós-Navarro and his colleagues set video traps at one latrine in the Monteverde Cloud Forest Preserve. Two months later, they were astonished to find 17 different mammal species had used it.

“It was crazy,” he says. “It is almost the total number of canopy mammals that you can find in the cloud forest.”

There were about three visits a day. Wildcats known as margays sprayed urine there, apparently to mark territory. Porcupines toileted and rubbed branches, leaving scent. Opossums, white-faced capuchins and coatis passed through, as well as howler monkeys and weasels.

Even two-toed sloths, which were thought to defecate only on the ground, did so there.

The team checked 170 further trees and found more latrines, but only in this species of strangler fig. There are now anecdotal reports of strangler figs also providing latrines in Honduras and Borneo, says Quirós-Navarro.

This toilet sharing is “fascinating and highly unusual”, says Neil Jordan at the University of New South Wales, Australia, who wasn’t involved in the study. “It’s super hard to study animals 30 metres up in the canopy. So it’s not surprising that it hasn’t been discovered before.”

Some ground-dwelling animals, such as rhinos and hyenas, are also known to use communal latrines. Scientists think these places enable animals to mark territory, exchange information about each other, provide waymarks and keep faeces in one place – partly to prevent predators from sniffing them out elsewhere.

A strangler fig is a spectacular plant that gradually envelops its host tree, often killing it. Ficus tuerckheimii has a cluster of branches at canopy height “like an [upturned] hand”, says Quirós-Navarro, creating a “comfortable, protected well in the middle”.

Its extra-long branches – he estimates 12 metres – provide highways even across rivers, potentially making them disproportionately important in the forest.

The trees are popular with climbers, some of whom camp on the latrine platforms. Quirós-Navarro fears that “by just disrupting one [strangler fig] tree, you can affect the whole communication between one forest and the other forest”, with ripple effects on the ecology.