Jaguars could disappear from the Atlantic Rainforest

Brazilian researchers warn that the biome only has 250 adult animals distributed across eight isolated populations, and only 50 are reproducing.

By Karina Toledo

Agência FAPESP – The Atlantic Rainforest is facing the imminent loss of one of its most celebrated inhabitants: the jaguar (Panthera onca). A group of Brazilian researchers, members of the Brazilian Biodiversity Research System (Sisbiota), sounded this alarm in a recent letter published in the magazine Science. 

“A recent meeting of wildlife specialists concluded that the Atlantic Rainforest, which previously extended along the entire Brazilian coast and part of Argentina and Paraguay, could soon be the first tropical biome to lose its main predator, the jaguar,” noted scientists in the letter.

“Researchers estimated that there are fewer than 250 live adult animals in the biome, distributed in eight isolated populations. Worse yet, molecular analysis demonstrates that the size of the effective local population (the number that is actually reproducing and leaving descendants, a critical parameter for maintaining genetic diversity) is below 50 animals,” they stated.

According to Ronaldo Gonçalves Morato, co-author of the letter and head of the National Carnivorous Mammal Research and Preservation Center (Cenap) at the Chico Mendes Biodiversity Conservation Institute (ICMBio), among the causes of the decline is the loss of habitat resulting from deforestation and fragmentation, and hunting. According to estimates, only 7% to 12% of the original Atlantic Rainforest remains.

The impact of the disappearance of the jaguar on local ecosystems is difficult to forecast, but it will certainly be negative. “When a large predator disappears, there can be an explosion of herbivores, such as deer, wild hogs and the white-lipped peccary. In excess, these animals end up consuming the entire sub-forest, and this has implications for recomposition capacity and loss of carbon stock. In the long term, it could lead to a dramatic decline in the forest’s dynamics,” evaluates Morato.

Pedro Manoel Galetti Junior, professor at the Department of Genetics and Evolution at Universidade Federal de São Carlos (UFSCar) and co-author of the letter, observed that the disappearance of the jaguar could still cause an uncontrolled increase in the populations of intermediary predators, such as the ocelot and other carnivores.

This increase, in turn, could cause an increase in nest predation and potentially result in the local extinction of many birds, which are important for seed dispersal, and changes in the structure of the vegetation. “The predator at the top of the chain has a role in regulating the ecosystem, and when it disappears, a disturbance is created. This could cause the extinction of some species until the ecosystem finds a new balance,” commented Galetti, who coordinated the FAPESP-funded study under the auspices of Sisbiota – a program launched by the National Council of Scientific and Technological Development (CNPq) in 2010 that brings together researchers from several states and, in São Paulo, is funded by FAPESP.

Strategic plan for conservation

The initiative to sound the warning in Science, according to scientists, emerged after a meeting sponsored in September 2013 by Cenap with the objective of elaborating a strategic plan for jaguar conservation in the Atlantic Rainforest.

“In the week before the event, another article had been published in Science on the recovery of carnivore populations in the Northern Hemisphere thanks to measures adopted more than 20 years ago, such as reforestation, and the reintroduction and translocation of individuals. Certain handling techniques utilized there allowed a number of the practically extinct species to occupy certain areas. Our letter aims to make this a counterpart to that article,” explained Morato.

The event promoted by Cenap brought together several members of the Sisbiota network. The group’s objective is to broaden the knowledge of not only predators but also all of Brazilian biodiversity, as well as improving the capacity to predict responses to changes in land use and coverage and to climate change.

According to specialists, the most urgent measure to save the jaguar would be increased monitoring to prevent losses of individuals caused both by hunting and by the degradation of the environment caused by illegal deforestation.

“First, we need to stem the losses so that we can then think about working to recover the populations. We are discussing the possibility of translocating individuals (placing new animals into an existing population to insert new genetic information to the group) because these analyses have shown that genetically many of these remaining populations are compromised. Even if the loss of animals stops, it will still be necessary to rebuild these populations,” affirmed Morato.

Another possibility, explained the Cenap researcher, is to utilize assisted reproduction techniques. “We can collect semen from an individual in one region and inseminate a female in another population, for example. The mechanism could be more practical than translocation,” comments Morato.

According to the plan developed by Sisbiota, no animal would be released without a 24-hour monitoring system and without prior education and consciousness-raising efforts inthe surrounding communities. “A serious effort must be undertaken to ensure that these communities accept the return of this animal. There must be orientation so that there is no risk of contact with the human populations and so that there is livestock management to prevent hunting for fear of economic losses.”

For Galetti, before any other measures are taken, there must be broader scientific knowledge about the jaguar – which includes information on the biology, ecology, genetics and systems that include it, or, rather, the other organisms that interact with it. “We cannot think about translocating animals in the absence of safety and control of the impacts,” he pondered.

Many of the studies that are based on discussions of the jaguar recovery plan were conducted under the auspices of Sisbiota, which is completing its third year of operation. Portions of the data were presented at the 1st Brazilian Symposium on the Functional Role of Predators at the Top of the Chain, held in São Carlos December 9 -10, 2013.

The article, Atlantic Rainforest's Jaguars in Decline (DOI: 10.1126/science.342.6161.930-a), by Ronaldo Morato, Pedro Galetti and others, can be read by subscribers of Science at www.sciencemag.org/content/342/6161/930.1.full?sid=b8928fb9-3760-4f2e-9188-23bc28d2dc2f.