The jaguars that live in the RDSM (Mamirauá Sustainable Development Reserve) in the Amazon live on trees for up to four months a year, while the Amazon floods the region and the forest can remain 0.5 to 7 meters under water.
Jaguars can swim and climb trees – they are extremely skillful animals – but this is the first time scientists have observed cats this large that spend long periods of time at height and are fully adapted to the conditions of the Amazon to survive. There they feed, reproduce and even raise their young, surrounded by water.
The behavior of Mamirauá’s animals was described by Brazilian researchers in the journal Ecology in an article published in January this year.
RDSM covers an area of more than 11,000 square kilometers in the Tefé region (a city about 522 km from Manaus). It was the first sustainable development reserve in Brazil. There, scientific research and nature conservation coexist with the local population, who use the natural resources of the reserve according to sustainable management plans.
It was the contact with local residents that first alerted the scientists at the IDSM (Mamirauá Sustainable Development Institute), who are researching the unusual behavior of jaguars in this area, says Emiliano Ramalho, biologist, technical and scientific director of the institute and one of the authors of the article in ecology.
“An area that, like Mamirauá, lies entirely in the lowlands and is inundated by forests every year, is a special environment, and the animals that live there have to be adaptable, just like the people,” says Ramalho. “Soil animals cannot survive,” he adds.
According to the residents’ reports, the scientists decided to monitor the animals to see if they could not escape to dry areas during the floods. To this end, the researchers captured some jaguars and placed collars with trackers on each. The study describes the behavior of eight animals, men and women.
During the screening, the scientists found that even the women did not leave Mamirauá during the floods, which can last about four months. In other words, the life cycle of the animals is fully adapted to the region even with seasonal floods.
“There was no description of an entire population of jaguars that were able to survive on trees for such a period of time. This is unprecedented behavior for cats of this size, ”says the biologist.
The jaguars of the Amazon exhibit physical differences that make it easier to survive in the region. Compared to those in the Pantanal, for example, the animals of the same species that live in the Amazon are smaller and can weigh up to half the weight of a Pantanal jaguar.
“The Pantanal jaguar would hardly survive in the Amazon. because it is bigger, it would need a lot more nutrition. Natural selection has chosen smaller animals to live in the Amazon rainforest, where there is no benefit in being big, ”says Ramalho.
Amazon animals weigh between 50 and 70 kilos, while jaguars in the Pantanal can reach 120 kilos.
Thus, smaller animals that live in the trees, such as sloths and howler monkeys (or guariba), please the jaguars during the floods.
In the end, Mamirauá’s environment and the jaguar’s diet seem to work very well there. The number of animals of the species in the reserve flourished: Ramalho estimates that in Mamirauá there are ten ounces per 100 square kilometers, while in other parts of the Amazon the number of ounces would be between two and four for the same area.
“Although it’s a difficult environment to live in, it’s also very productive. When the water dries, the clay with the nutrients fertilizes the soil. A very large number of species live in the region, ”says Ramalho.
If the jaguar population is large today, the biologist warns that the conservation scenario in the area can change rapidly as protected areas are degraded. Deforestation in the Amazon in March was the highest in six years, according to Deter, a deforestation monitoring system from Inpe (National Institute for Space Research).
For Ramalho, investment in research in the Amazon must be continuous to protect the forest. “Only then do we have the knowledge to implement conservation strategies,” he says.