Researchers from Oregon State University and the Wildlife Conservation Society of Guatemala used trail camera footage and DNA analysis of scat to study jaguars, pumas, ocelots and margays in the Maya Biosphere Reserve. They found that jaguars and ocelots primarily hunted ground-dwelling prey, while pumas and margays more frequently consumed animals that live in trees.
Among the most surprising findings: Central American spider monkeys and black howler monkeys were the primary prey of pumas, contributing more than twice as much to their diet as red and gray brocket deer and ocelots made up 10% of jaguars' diet and 2% of pumas' diet.
"This research challenges long-held assumptions about how large carnivores coexist without competitively excluding each other and highlights the importance of vertical foraging stratification," said Ellen Dymit, a doctoral researcher at Oregon State University. "As habitat loss and climate change reshape ecosystems, understanding how predators partition resources will be critical for conservation."
A central question in ecology is how similar species share the same environment. Theory suggests they must divide their resource use along one or more niche axes - space, time or diet - to reduce competition.
While interactions among large carnivores are well studied in African savannas, few studies have explored these dynamics in rainforests, where vertical space plays a larger role. Evidence shows that wild cats hunt both terrestrially, or on the ground, and arboreally, or in trees, but this study is among the first to quantify that behavior in terms of diet composition.
The research took place in remote protected areas within the Maya Biosphere Reserve, a subtropical forest spanning more than 8,000 square miles in Guatemala, Belize and Mexico. Some field sites required up to eight hours of ATV travel to access.
To evaluate how the four cat species used the habitat, Dymit and the research team used camera trap footage from trails and in the canopy to study where the animals were and at what time, and scat samples to understand what they were eating.
They analyzed 215 scat samples, 156 of which were collected by field crews and 59 by two dogs, Barley and Niffler, who are trained to detect scat. The scat was taken back to the lab of Taal Levi at Oregon State, where Dymit works, and through a process known as DNA metabarcoding, the researchers determined what the cats had eaten.
DNA analysis revealed that:
+ Jaguars primarily consumed pig-like peccaries and nine-banded armadillos, and to a lesser extent ocelots and brown brocket deer.
+ The main prey for pumas were monkeys, followed by brocket deer, peccaries and lowland pacas, which are relatively large rodents.
+ Ocelots primarily consumed small-to medium-sized mammals, with large opossums, small opossums and Gaumer's spiky pocket mouse occurring at the highest proportions.
+ Margay scats contained mice, small arboreal opossums, large opossums and rats.
+ The diet of each cat contained different numbers of unique prey species: jaguar, at least 20; puma, 27; ocelot, 25; and margay, 7.
Researchers didn't capture any video of pumas in trees in this study and are not certain how pumas hunt monkeys and tree-based mammals, but puma hunting behavior in the canopy has been documented elsewhere.
One possibility is that pumas target monkeys and other arboreal animals when they descend to the ground to forage or drink. However, the relatively high frequency of monkeys in the diet of pumas, the near absence of monkeys from the diet of jaguars and ocelots, and the absence of video of monkeys at water holes suggest that pumas may be hunting in the lower canopy, the researchers note.
The researchers believe pumas may have the ability to forage in trees because they weigh less than jaguars. Also, the enhanced bite force of jaguars likely facilitates their consumption of hard-bodied armadillos.
The researchers analyzed footage from 55 cameras on the ground and 30 in the canopy, at an average of 40 feet in the trees. Those cameras were set up by scientists from the Wildlife Conservation Society of Guatemala, who are focused on protecting the Central American scarlet macaw parrot and leading other conservation-focused research projects.
They captured 1,550 independent detections of jaguars, 1,482 of pumas, 1,378 of ocelots and 188 of margays. Of the margay detections, 156 were at ground level and 32 were in the canopy. Jaguar, puma and ocelot were only detected at ground level. The footage showed that pumas and jaguars had similar activity patterns in terms of time and space on the landscape, as did ocelots and margays.
Research Report: Niche partitioning among neotropical felids
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