It is the conservationist’s catch-22: what to do when one endangered species starts eating another. That is the problem facing environmentalists whose research shows that jaguars, themselves at risk of extinction, are increasingly preying on endangered turtle species.
Experts said that the predation of adult turtles by the big cats in a Costa Rican national park “has now reached a magnitude never before recorded”.
“More and more jaguars are being pushed towards the coastline, where they find sea turtles, which are easy prey,” said Diogo Verissimo, researcher with the Durrell Institute of Ecology and Conservation and Global Vision International.
Figures on marine turtle deaths attributable to jaguars were not collected before 2005. But, in his paper, ‘Jaguar Panthera onca predation of marine turtles: conflict between flagship species in Tortuguero, Costa Rica’, published in Oryx, the International Journal of Conservation, Mr Verissimo argued that the 676 recorded deaths in the five years hence was an extraordinarily high figure.
“There are no cases of this type of behaviour that I am aware of,” he said yesterday. Some argue that people should not interfere in what is essentially a natural, evolutionary process. However, in this case, increasing deforestation was blamed for causing the cats to look further afield.
Mr Verissimo said that making prey more easily available in the cats’ natural habitat in the Tortuguero National Park could ease their propensity to hunt endangered green turtles, as well as hawksbills and leatherbacks, which have also been taken in smaller numbers.
He said: “Having researchers of different specialties communicate among themselves is important. Otherwise, it would be easy to miss cases like these types of problems. Often, one team is only responsible for the welfare of one species or a certain group and will not be as concerned about that of another.”
Joseph Tobias, a conservation biologist at Oxford University, said that the phenomenon may be part of a natural, long-term trend but said that, if not, it posed a difficult problem to solve. “Costa Rica has a good reputation in terms of conservation but, to stop it you need to protect large areas of forest, because the jaguar is a very long range hunter.
“You need to bear in mind that people in that part of the world need to feed themselves and protect their livestock, so you cannot necessarily insist they clear no areas of forest. But the world has never seen deforestation on this scale before and it would be blasé to suggest that the situation should be left as it is,” he said.
The green turtle is classified as endangered and the leatherback and hawksbill turtles as critically endangered. Jaguar populations in Costa Rica are also considered to be highly threatened. The kills, all of which were green turtles with the exception of three hawksbills and one leatherback turtle, were attributed to jaguars because they were carried out with a single bite to the neck, common to the big cat.