On the Trail of Big Cats: Jaguars in Brazil
Martin Main, Ph.D., Professor in the Department of Wildlife Ecology & Conservation and his PhD graduate student, Emiliano Ramalho, are on the trail of Brazil’s big cats, the elusive, ecologically important jaguars. With their range shrinking in a north-south squeeze play, jaguars are caught in the middle, where human development is fragmenting their habitat.
Those facts make the Amazon Basin critical to the conservation
of jaguars. According to some estimates, it holds the largest population of jaguars, contains the largest non-fragmented stretches of habitat, and maintains connections with other ecosystems critical to jaguars’ survival.
Jaguars function as top predators, regulating the populations of their prey and of smaller predators. That fact makes jaguars important to the health of their native ecosystems. However, no one knows how many jaguars still exist. They are solitary animals and their preferred habitat in the Amazon is dense tropical forest with access to plenty of water. They are hard to find and hard to count.
Populations of jaguars have been studied in other biomes, but not in the Amazon varzea (flooded rainforest). The jaguar’s plight brought Main to Brazil, where he is working with Ramalho, a CAPES/Fulbright scholar and native Brazilian. Together, they are working to estimate density and study the ecology of jaguars in the Mamirauá Sustainable Development Reserve, located entirely within the varzea. http://www.mamiraua.org.br
Ramalho has worked for several years at the Mamirauá Reserve and is tracking the big cats in two ways. Infrared-triggered cameras are strategically placed across an area of some 350 km2 to estimate jaguar density. The cameras have revealed a high density, roughly 13 jaguars per 100 km2, with many females and cubs, suggesting the habitat is an important breeding ground.
Ramalho and Main also captured the first of what they hope will
eventually be eleven jaguars. They fitted the female with a GPS collar that will record her location every 2 hours for the next year. The data will determine her range and possible migration pattern as water levels change with the pulse floods from the Amazon River. The floods change water levels by 11 vertical meters (~36 feet), driving the lateral movement of wildlife, possibly including jaguars.
No one knows for sure if jaguars migrate in these flooded forests or where they go if they do. In an effort to find out, the team is collecting information on density and movement of jaguars, their diets, and the availability of prey for jaguars in the study area.
Below: a map of the study area.
Please note that the name "Solimões River" is a local designation for the Amazon River. Locals refer to the upper reaches of the Amazon by this name. The study area (red circle) therefore lies astride the corridor between the Amazon (Solimões) and Japurá Rivers. The red dot is the town of Tefé.
A UF/IFAS travel grant helped set up the study in collaboration with Mamirauá Reserve, which assists with funding, equipment, and a “floating camp” from which Main and Ramalho stage their research activities. Local village trackers provide important assistance with all phases of the research, including collecting jaguar “scat” so Ramalho can determine which animals the jaguars have consumed.
Main and Ramalho hope to gather data crucial to the conservation of the jaguar, which comes into conflict with humans outside the Mamirauá Reserve. The main conflict is with cattle ranchers and villagers, who often shoot jaguars on sight. Ramalho is educating local villagers about jaguars in efforts to change these behaviors.
Unfortunately, human presence in the varzea has expanded enormously, as the region is important in the local economy and in the economies of major cities. The increasing human population in the region spells trouble for the varzea’s top predator. Main and Ramalho hope to gather information that will give the jaguar a fighting chance.
Contact: Marty Main, mmain@ufl.edu
Meet "Elvira," a jaguar trapped and fitted with a GPS collar, then released as part of Marty Main's and Emilio Ramalho's research into jaguar ecology and conservation in Brazil's varzea, or flooded rainforest.
Left: jaguar tracks left by the elusive top predator of Central and South America. As the largest cat species in the Americas, jaguars are important in regulating the populations of prey animals and smaller predators who compete with them for food.
Solid masses of color in the jaguars’ current range may be misleading, because no one knows how many jaguars exist or how fragmented their populations are within these regions.
Left: jaguar forest habitat shown during the dry season and the flooded wet season, when water rises some 36 feet in the rainforest. Main and Ramalho hope to determine whether jaguars migrate out of the flooded forest and if so, where they go and which populations migrate or stay, e.g. solitary males or females with cubs.
This floating camp houses Marty Main's graduate student, Emiliano Ramalho, who is conducting the bulk of the research on jaguars. The camp is on loan from the Mamirauá Reserve as part of the Reserve's support for this research.
This infrared "camera trap" is one way Main and Ramalho are gathering their data about jaguar densities and movements through the flooded forests. Main and Ramalho have placed enough camera traps to cover an area of some 350 square kilometers.
Left: Sleeping Beauty: Marty Main's team caught their first jaguar, "Elvira," on Halloween, hence her name! The young jaguar may be pregnant. The team will track her movements through a GPS-system collar. Left to right: Joana Macedo, project assistant; Martin Main, UF/IFAS faculty; Emiliano Ramalho, PhD student; and Dairen Simpson, wildlife capture specialist.
The Black caiman, a relative of the crocodile, is one of the jaguar's favorite prey. Jaguars raid nests as well as eat the adult caiman.
An unexpected ecological bonus: Marty Main holds the lunch that catches itself... This odd fish is an arawana. The locals call them “river monkeys” because they jump out of the water. The fish Dr. Main is holding jumped into his boat, providing a
"fresh-caught," unexpected lunch for the crew.
