How to track animal of legend? Look to the poop

A team of researchers led by the University of Cincinnati applied isotopic analysis to jaguar scat to investigate the habitat needs of the big cats in the Mountain Pine Ridge Forest Preserve of Belize in Central America. The study demonstrates a novel and noninvasive technique for identifying the landscape use and conservation needs of elusive wildlife.

The Mountain Pine Ridge Forest Reserve covers about 267 square miles of forest, savanna, rocky  mountains, caverns and streams in central Belize. The reserve is logged on a rotating basis. The roads are largely unpaved and many are overgrown.

Tracking animals here is extremely difficult, said Claudia Wultsch, a study co-author and research fellow at the City University of New York.

“Jaguars occur at low densities,” Wultsch said.

“They move around a lot and are among the most elusive large carnivores. They tend to stay away from people and are typically found at more remote sites. You have to be extremely lucky to see one in the wild.”

Isotopic analysis is a good alternative to study an animal that is solitary, wide-ranging, nocturnal, wary of people and dangerous to capture. And it complements other wildlife surveillance methods such as camera trapping, acoustic monitoring and environmental DNA analysis.

“I am so grateful for the opportunity to conduct this collaborative study,” Crowley said. “I have been interested in noninvasively monitoring the habitat use of animals for a while.” 

Strontium is a naturally occurring element found everywhere on Earth. The isotopes are released from rocks into the water and soil, where they enter the food chain through the vegetation. Likewise, nitrogen and carbon isotopes provide clues about what types of animals the jaguar was eating and the habitats where they lived.

Bigger than leopards, jaguars are the world’s third-largest cat and the biggest found in the Western Hemisphere. They are powerful apex predators that were revered by pre-Columbian societies. Opportunistic hunters, jaguars consume a wide variety of prey, including small mammals, birds, fish and reptiles. In Belize, they often eat armadillos, coatis and deer.

“Belize is an important stronghold for jaguars,” co-author Wultsch said. She is studying the big cats with study co-author Marcella Kelly, a professor at Virginia Tech.

In Belize, jaguars are protected and live in a network of dedicated reserves. Wultsch and Kelly in 2000 found that jaguars had a large enough population to maintain genetic diversity in Belize but did see some habitat loss and fragmentation in parts of their historic range.

The jaguars studied in the latest project hunted prey in the reserve’s pine forest savanna rather than in denser forest or nearby agricultural areas. Male jaguars had territory covering some 60 square miles. As in other areas where jaguars have been studied, researchers found that some of the male jaguars had partially overlapping territories.

“A lot of the scat was collected in the central part of the preserve. One jaguar will poop on another’s scent to mark its territory,” Crowley said. “It seemed like the jaguars we studied were all trying to claim that area.”