Camera traps at the Cocha Cashu Biological Station in the Peruvian Amazon were meant to record birds. Instead, one night in 2023, they captured something that left scientists silent: an ocelot (*Leopardus pardalis*) walking along a forest trail with a common opossum (*Didelphis marsupialis*) trailing calmly less than two meters behind.
There was no chase, no wariness—none of the tension millions of years of evolution would predict between a predator and its natural prey. Study lead Isabel Damas-Moreira, a behavioral ecologist at Bielefeld University, later told The New York Times the pair looked "like two old friends walking home from a bar."
This was not a one-off. Between 2019 and 2023, the team independently recorded the same scene four times at four different Peruvian Amazon sites—always with the opossum in front and the ocelot following. In June 2025, the study was published in *Ecosphere*: *Beyond predator and prey: First evidence of an association between ocelot and opossum individuals* (https://doi.org/10.1002/ecs2.70322).
Two Research Threads Converge
The discovery began with two separate lines of work. In Peru, Ettore Camerlenghi (ETH Zurich) and colleagues found the trail-camera footage while studying birds. In Panama, Dumas Gálvez (Smithsonian Tropical Research Institute) was testing whether agoutis (*Dasyprocta punctata*) avoid areas with ocelot scent. They do—but surprisingly, opossums were strongly attracted to ocelot odor, sniffing, rubbing against, and even biting scent-treated cloth strips, while largely ignoring puma scent and controls.
The two researchers met at a behavioral ecology conference in Melbourne in 2024 and combined their evidence into one paper. As Damas-Moreira put it, science often advances "through serendipity, curiosity, and collaboration."
Three Hypotheses
- Chemical camouflage by the opossum: The opossum may rub against ocelot scent to carry the smell of a predator, deterring other threats (jaguars, pumas, raptors) that would otherwise attack it.
- Reverse camouflage by the ocelot: The opossum's famously musky odor may mask the ocelot's own scent, letting it approach scent-sensitive rodent prey undetected—the predator disguised as a harmless neighbor.
- Cooperative hunting: Opossums are naturally immune to viper venom thanks to a small peptide in their blood. An ocelot with an opossum 'scout' could more safely prey on dangerous snakes—though no direct evidence of this exists yet.
- Is this behavior individual-level or population-level?
- Do opossums actively choose to follow ocelots, or is it coincidence?
- What actual benefit does the ocelot gain?
- How widespread is this behavior across the Amazon?
- Camerlenghi, E., Gálvez, D., Ketola, C., Piga, A., Holmes, N., Mena, J.L., Tobler, M.W., Rayan, F., & Damas-Moreira, I. (2025). Beyond predator and prey: First evidence of an association between ocelot and opossum individuals. *Ecosphere*, 16(6). https://doi.org/10.1002/ecs2.70322
- Coverage: Smithsonian Magazine, Mongabay, The Wildlife Society, Bielefeld University
An Olfactory Arms Race
Whichever hypothesis holds, the finding highlights the underestimated role of smell in animal relationships. In the rainforest's invisible chemical map, scent can be borrowed, faked, and weaponized—comparable to the 'chemical crypsis' of puff adders or chemical mimicry by parasitic wasps.
It also parallels the coyote–badger hunting alliance in North America, where 90% of joint hunts are one-to-one pairs. But unlike coyotes and badgers, ocelots can easily kill opossums—which makes their tolerance of a potential meal trailing behind all the more puzzling.
Open Questions
The researchers cautiously describe this only as an 'association.' Key unknowns remain:
Gálvez's next step is a control experiment on Coiba Island, Panama, which has opossums but no ocelots or other large predators. If opossums there still prefer ocelot scent, the attraction is innate; if not, it is learned—a test of whether this cross-species cooperation is instinct or experience.
> "I wonder how many of these weird interactions are happening that we're unaware of because they're difficult to record in the field." — Dumas Gálvez
If such associations can persist unnoticed between two of the Amazon's most common animals, countless others may await discovery—in the deep sea, the forest canopy, and the blank spaces of our incomplete food webs.
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