A frame from a video provided by Nadine Holmes shows an ocelot and an opossum together in the Amazon. Scientists are trying to understand footage that showed ocelots and opossums, usually predator and prey, hanging out together. Photo / Nadine Holmes via the New York Times
A frame from a video provided by Nadine Holmes shows an ocelot and an opossum together in the Amazon. Scientists are trying to understand footage that showed ocelots and opossums, usually predator and prey, hanging out together. Photo / Nadine Holmes via the New York Times
Screenwriters in search of the next Timon and Pumbaa may want to look to the Amazon, where unlikely ocelot-opossum duos have been filmed hanging out together.
Researchers at Cocha Cashu Biological Station in southeastern Peru set up a camera trap to study bird behaviour, but they got a surprise guestappearance instead: an ocelot trailing an opossum through the jungle at night.
The ocelot, a wildcat slightly larger than a house cat, and the common opossum, a marsupial, are usually predator and prey. But in this video, they moved in tandem.
“We were sceptical about what we had seen,” said Isabel Damas-Moreira, a behavioural ecologist at Bielefeld University in Germany.
Perhaps the ocelot was shadowing its dinner-to-be to learn about its behaviour, they wondered, although that didn’t explain the opossum’s laid-back behaviour.
Then came a second clip: the same odd couple wandering back along the trail minutes later.
“Like two old friends walking home from a bar,” Damas-Moreira said.
Intrigued, they contacted researchers in other parts of the Amazon who turned up three additional, nearly identical videos from different locations and years.
Damas-Moreira and her colleagues then set up an experiment, which they described last month in the journal Ecosphere.
They left strips of fabric infused with ocelot scent, puma scent and a control in front of camera traps.
Opossums visited the ocelot scent 12 times, often lingering to rub against, sniff, or bite the fabric. The puma scent attracted just one brief visit.
Opossums’ attraction to ocelots remains a mystery, but Damas-Moreira and her colleagues suspect there’s something that draws both animals. One hypothesis is “chemical camouflage”.
“Opossums have a strong smell, and a close-by ocelot might help hide the opossum’s scent from bigger predators, or the opossum’s odour might mask the ocelot’s presence from prey,” said Ettore Camerlenghi, an evolutionary biologist and ecologist at ETH Zurich and an author of the study.
A frame from a video provided by Ettore Camerlenghi, Isabel Damas-Moreira, Angelo Piga shows an ocelot and an opossum together in the Amazon. Photo / Ettore Camerlenghi, Isabel Damas-Moreira, Angelo Piga via the New York Times
Opossums are also resistant to the venom of pit vipers, a type of snake that lives in the Amazon.
Ocelots lack that defence and teaming up could give both animals an edge when hunting, Camerlenghi said.
In North America, a similar alliance exists between coyotes and badgers, who buddy up to hunt squirrels.
The finding doesn’t surprise Erol Akcay, a theoretical biologist at the University of Pennsylvania who was not involved in the research.
“We tend to underestimate how much co-operation there is in nature,” he said.
One of Akcay’s favourite examples of what scientists call hunting mutualism is between honeyguide birds and humans.
The birds lead people to bee nests, and when humans crack them open for honey, honeyguides feast on beeswax.
As for opossums and ocelots, Akcay suspects a similar trade-off: “Opossums might guide the ocelot to prey it cannot itself take down, but they can feed on the carrion that ocelots leave behind,” he said.
Diego Astúa, a professor and curator of mammals at the Federal University of Pernambuco in Brazil whose research focuses on opossums, called the study “really cool!”
Considering that opossums are solitary creatures who don’t even hang out with their own kind outside of family or mating, this behaviour is unexpected, he said.
But the finding also highlights something Astúa knows well: Research on opossum behaviour is still in its infancy.
“We are likely to find more and more surprising records like this,” he said.
Without video camera traps, the discovery might never have happened.
Both species are nocturnal and elusive, making direct observation in dense rainforest difficult, Camerlenghi said.
And “the video footage revealed interactions that photos alone could have easily been mistaken for predator-prey encounters”, Damas-Moreira added.
While the behaviour itself remains puzzling, that it was captured on film is pure serendipity.
“Science often works like that,” Camerlenghi said.
“You search for one thing and end up finding something else, which sometimes turns out to be even more interesting than what you were originally after.”
