A jaguar in Brazil has been documented making a record-breaking swim of up to 1.54 miles (2.48 kilometers). This distance is far beyond the previous verified record of around 650 feet (200 meters) for jaguars, according to the study authors.
Jaguars (Panthera onca) are adept swimmers, often inhabiting rainforest regions threaded with rivers that frequently overflow their banks. They dive into the waters of their Central and South American range without hesitation — but these dips are normally brief and undertaken to capture prey such as caimans, fish and turtles.
However, in a paper that appeared Sept. 10 on the preprint server bioRxiv, which has not been peer-reviewed, scientists documented a jaguar swimming a much greater distance.
The researchers reported that a male jaguar, first documented by camera trap photographs in May 2020 near the Serra da Mesa Hydroelectric Power Dam in Brazil's Goiás state, swam at least 0.79 miles (1.27 km) to reach a small island in an artificial lake created by the dam.
A camera trap stationed on the island captured the same male four years later, in August 2024. The spot patterns on its coat were used to verify that it was the same individual. An analysis of the distance between the mainland and the island in the reservoir showed that there were two possible ways for the jaguar to have reached the island.
First, it could have swum 0.66 miles (1.07 km) to a small islet before reentering the water and then swimming the remaining 0.79 miles. If the jaguar swam directly from the mainland to the island without stopping, it would have covered 1.54 miles in a single go, the researchers said.
Even if the swim were undertaken over two journeys, this still represents a record-breaking distance for jaguars, the authors wrote.
It is unclear why the jaguar made the swim. "Prey in this region appears to be fairly evenly distributed, lead author Leandro Silveira, a biologist with the Jaguar Conservation Fund, told Live Science. "Nothing suggests the island has more prey, nor do the shorelines. We think he decided to explore a new area — more likely related to searching for females or territory than a lack of food.
"We generally expect animals to seek the best cost-benefit option for movements, choosing narrower, less risky crossings," he added. "That's why this record was so surprising."
However, Fernando Tortato, a project coordinator for the big-cat conservation organization Panthera who wasn't involved with the paper or observations, notes that long swims probably are not unusual for jaguars.
"Most of the jaguar population is located in the Amazon basin," he told Live Science. "The main rivers there are in many places much larger than 1.6 kilometers. Some places are more than 10 kilometers. We know that jaguars do not see a river as a barrier."
Tortato thinks the jaguar may have been seeking a new location to hunt capybaras (Hydrochoerus hydrochaeris), another common source of prey. "It's quite common to see capybaras along these artificial lakes," he said. "That's my bet."
