520149430

Photo by: Joe McDonald

Joe McDonald

Beneath the Water in South America’s Wetlands Lurk Hundreds of Swimming Jaguars

Fish-eating jaguars prowl the wetlands of Brazil, Bolivia, and Paraguay exhibiting extremely unusual behavior to scientists.

October 21, 2021

Jaguars are the largest cat species in the Americas and the third-largest in the world. Normally highly territorial loners, these opportunistic predators hunt capybaras, deer, and other land mammals.

In Pantanal, the largest tropical wetland in the world, that sprawls across Brazil, Bolivia, and Paraguay lives a different type of jaguar. Or rather jaguars that have adopted a diet rich in fish and aquatic reptiles.

Jaguars will eat any small species that can be caught, including  fish, frogs, mice, birds, sloths and monkeys. They regularly take adult caimans, deer, capybaras, tapirs, peccaries, dogs, and sometimes even anacondas.

480292218

Jaguars have even been documented jumping into the ocean in Brazil to hunt for fish.

Photo by: Windzepher

Windzepher

Jaguars have even been documented jumping into the ocean in Brazil to hunt for fish.

These big cats spend a huge portion of their lives wading through chest-deep water searching for fish to eat in the wetlands. Back on land, they playfully grapple with each other – a behavior and diet previously unseen in jaguars.

After scientists from the Universidade do Estado de Mato Grosso in Cáceres, Brazil observed these behaviors they set up a project to better understand jaguar behavior in the area.

Near Brazil’s Taiamã Ecological Station, the researchers set up motion-activated cameras to count jaguar populations. On the journey to set up the cameras, however, the abundance of local jaguar populations was already clear.

“You set your foot out of the boat, and there’s a jaguar footprint there already,” said Charlotte Eriksson, a wildlife scientist at Oregon State University. “There are scratches on trees. There are jaguar scats. There’s just an unbelievable presence of this apex predator wherever you go, which is something I’ve never experienced anywhere before.”

1194958170

These apex predators are excellent swimmers.

Photo by: Delta Images

Delta Images

These apex predators are excellent swimmers.

Between 2014-2018, using 59 cameras the team capture more than 1,500 videos of jaguars. Additionally, the team tagged and tracked 13 jaguars with GPS collars. The data revealed the highest density of jaguars ever recorded – with Taiamã Ecological Station hosting 12.4 of the large cats per 100 kilometers squared.

Video footage showed the jaguars swimming, hunting for aquatic animals, and eating fish. More than half of the jaguar scat sampled had fish remains in them, meaning these jaguars have the most fish-dependent diet of any big cat ever recorded.

Even more surprisingly, the collars revealed these jaguars spent a lot of time together- hunting, fishing, playing, and socializing. Based on previous studies, this is extremely unusual behavior for jaguars who normally spend their lives alone, meeting up sparingly to mate.

Jaguar (Panthera onca) hält Ausschau, Pantanal, Mato Grosso do Sul, Brasilien, Südamerika

1087845296

A pair of jaguars in Pantanal, Mato Grosso do Sul, Brazil.

Photo by: Matthias Graben

Matthias Graben

A pair of jaguars in Pantanal, Mato Grosso do Sul, Brazil.

The researchers hypothesize it is the wetlands' rich biodiversity that allows for this behavior. With so much food to go around, there’s no reason for the jaguars to be in competition or fight over resources.

“We think we know a lot about these charismatic, large predators,” Eriksson says, “but there are still things to learn.”

Jaguars in Pantanal face many threats with the rise of climate change and deforestation. Learning how these animals live and adapt could be paramount in protecting them for future generations.

Next Up

Galápagos Giant Tortoises Are Mysteriously Turning Up Dead in Ecuador

Despite the tough protections, there has been a spate of tortoises killed in recent months, and officials fear the animals have been slaughtered for their meat.

The Ancient Monkey Puzzle Tree Outlasted Dinosaurs. Now It's Facing Extinction.

The monkey puzzle tree is a remnant of the Jurassic era, more than 145 million years ago, surviving way past its ancient dinosaur counterparts. Reaching heights of about 160 feet, the evergreen tree has a lifespan of up to 700 years and stiff scaly branches with rigid spiral leaves. Monkey puzzle trees’ presence in the wild is shrinking and after million years, their very existence is now endangered.

Is Climate Change Killing More Elephants than Poachers?

Kenya’s Wildlife and Tourism Board has announced that climate change is now a bigger threat to elephant populations than poaching. Kenya is currently facing an extreme drought that is threatening the livelihoods of people and wildlife within the area.

There is Hope for the Future of Polar Bears Threatened by Climate Change

Scientific researchers have recently identified a sub-population of polar bears in southeastern Greenland that survive by hunting on glacial slush. The discovery of their unique behaviors is helping scientists understand the future of this species whose habitats are threatened by climate change.

Two Orcas Are Hunting Great White Sharks in South Africa

A killer whale duo has been killing great white sharks off the Gansbaai coast, causing them to flee the area. These orcas have developed a taste for shark livers, transforming the local marine ecosystem.

The Highest Animal on the Food Chain: Megalodon Sharks

The now-extinct megalodon and its ancestors may have been "hyper apex predators," higher up on the food chain than any ocean animal ever known.

99% of Sea Turtles are Now Born Female. Here's Why.

Global warming is creating a crisis in sea turtles' gender ratios, where 99% of them are being born female. Sea turtle populations have been facing a significant population decline further exasperated by climate change.

Coral Reef Survival Relies on Gene Science and Lower Emissions

Coral reefs across the world are under threat as global warming raises sea temperatures and the oceans become more acidic from absorbing carbon dioxide. While nations work to reduce industrial greenhouse gases, including carbon dioxide, helping coral to adapt to changing conditions could provide welcome relief for affected reefs.

Why the Long Face? Extinct Headbutting Relatives Reveal Giraffes' Neck Evolution

Pioneered by Darwin, giraffes have been used as a classic example of how animals adapt and evolve. Giraffe’s long-neck evolution has long been attributed to foraging for sustenance in the high canopy, now researchers argue that selection for head-butting combat played a role in the long length of giraffe necks.

Are Sharks Coming Closer to Our Shores?

Scientists at the University of Miami Rosenstiel School of Marine and Atmospheric Science have speculated that variables related to high urbanization may be driving higher occurrences of sharks within coastal waters. With high increased levels of urbanization in coastal cities, it’s important for our world to understand how ocean life adapts to the changes in their habitats.