Study: Fragmented jaguar groups in Mexico show inbreeding

MEXICO CITY – A study of jaguar populations in Mexico and Central America shows significant levels of inbreeding in some areas, suggesting a new danger for a species that has disappeared from three-quarters of its original range.

The study published Wednesday in the journal PLOS ONE suggests that preserving isolated patches of tropical forest may not be enough to save the jaguar, which is considered a near-threatened but not yet endangered species.

Researchers from the American Museum of Natural History and Rutgers University examined DNA samples from the feces of 115 jaguars in Mexico, Honduras, Guatemala, Belize and Costa Rica. They found only moderate levels of genetic diversity in some populations.

The study said “diversity levels were lowest for jaguars in northeastern Mexico” and researchers found “moderate levels of inbreeding” there.

“Honduran jaguars exhibited the second lowest genetic diversity estimate among all Mesoamerican sites,” the study said. It added that “in northern and central Honduras jaguars inhabit fragmented forest patches and are potentially reduced to small population sizes.”

“Jaguars studied in Costa Rica, central Belize, and northern Guatemala showed the highest levels of genetic diversity … indicating overall moderate to high local population sizes,” it said.

The conservationist group Panthera said that “genetic diversity at such low levels decreases species’ overall health and potential to adapt and survive in the long-term.”

Craig Packer, director of the Lion Research Center at the University of Minnesota, said that “inbreeding has had serious consequences on Florida panthers and certain isolated populations of African lions, so it is a legitimate conservation concern.”

Because jaguars need a lot of space, their population density is low, and various populations ideally should be linked so jaguars from one area can travel and breed with other groups. But because of deforestation, roads and development, the big cats are instead isolated in small pockets throughout most of their northern range.

“To maintain a critical linkage for jaguars dispersing through the Mesoamerican landscape and ensure long-term viability of this near threatened species, we recommend continued management and maintenance of jaguar corridors,” the study said.

Stuart Pimm, the Doris Duke Professor of Conservation Ecology at Duke University who was not involved in the study, agreed it would be good to have wildlife corridors for the jaguars to move through, but he said that would be difficult in an area with a lot of deforestation.

“What it suggests, of course, is that eventually people are going to have to think about moving jaguars around in genetically rescuing some of those now in-bred populations,” Pimm said. “That’s hard work, it’s controversial, it’s expensive, but it’s probably going to be the only way in the long term to give these populations a chance.”

He said such transfers are fraught with risk and danger. “Capturing jaguars is very stressful, and you would want to move female jaguars into these areas, because if you brought males they would fight and kill each other and that wouldn’t serve any purpose.”

Salisa Rabinowitz, one of the authors of the study, wrote that “unlike some other big cats and wildlife teetering on the brink of extinction, here we have a remarkably resilient species whose numbers are strong enough to bounce back if given the chance to thrive. Let’s allow the jaguars of Latin America to live on by connecting their populations throughout human landscapes.”