For a rainforest animal like the agouti, life revolves around the tension between food and fear. While foraging for seeds from the black palm tree, the rabbit-sized rodent has to avoid hungry ocelots.
Living in an area where food is scarce greatly increases an agouti’s willingness to venture out of its burrow between sunset and sunrise, when the danger of being eaten by a nocturnal ocelot is four times greater, says Roland Kays, zoologist with NC State and the North Carolina Museum of Natural Sciences.
Kays is part of a team that used burrow cameras and radio collars to track individual agoutis in real time. Their research, published in the journal Animal Behaviour, compared agouti foraging in areas with abundant and scarce food supplies in Panama. Hungry animals took more risks.
“We were surprised that agoutis would go out in the dark, given how dangerous it is,” Kays says. “Our results show that agoutis really are stressed by lack of food.”
When an agouti fell prey to an ocelot, researchers could see a flatline signal within a minute and find the animal, using the collar signal. Watch a video showing ocelot hunting strategy at night.
Agoutis not only have to eat for the day but also hide seeds for the future, when black palm fruit is out of season. Animals in areas with more food generally went into their burrows earlier in the evening and came out later in the morning, minimizing their exposure during high-risk times.
“It’s important to understand the effects fear has on animal behavior and the ecological roles that agoutis fill,” Kays says. “This study provides quantifiable data about food security and predation risk that we haven’t had before.”
Read more from the Smithsonian’s Tropical Research Institute.