- A collaborative study has documented male jaguars engaging in cooperative behavior and forming multiyear partnerships in prey-rich areas in Venezuala’s Llanos and Brazil’s Pantanal.
- Though these partnerships remain rare, evidence of this and other cooperative behaviors challenges the notion that all felids, except for lions and cheetahs, are strictly solitary.
- The research reinforces the value of long-term studies using data from multiple sources to give a fuller understanding of a species’ ecology and behavior.
On the evening of March 15, 2016, two large jaguars walked along a narrow lakeshore trail in Venezuela’s Llanos ecosystem, a vast mosaic of seasonally flooded lowland savannas, forests, pastures and ranches. At 9:13 p.m., they passed a remote camera trap set by Włodzimierz Jędrzejewski, a researcher at the Venezuelan Institute of Scientific Research (IVIC), and his team, as part of their long-term study on jaguar population dynamics.
The camera tripped, catching the jaguars mid-stride in a moment of uncanny synchronicity; their right forelegs extended, left shoulders raised, football-sized heads held low and mouths loosely open. Except for their spot patterns — as unique to each jaguar as fingerprints are to us — the two look like carbon copies. But what is surprising about the photograph isn’t the symmetry of the image, but simply that the two, both males, are walking together.
Jaguars (Panthera onca) have long been considered loners that only come together to mate or to rear young. Now, research in the journal Behavioral Ecology and Sociobiology shows that in some cases male jaguars cooperate and even form coalitions.
The research documents male jaguars jointly patrolling and marking territory, chasing and likely killing other males, sharing prey, and more. It draws on data from five study areas in the Venezuelan Llanos and Brazil’s Pantanal. Two of the male coalitions even lasted more than seven years.
“The belief that jaguars are solitary and that different males must always be aggressive towards each other was very strong,” said Jędrzejewski, one of the authors of the study. He added he was surprised when data from his team’s long-term study on jaguars first hinted that two males, whom they’d dubbed M9 and M25, were spending time together.
“I thought that something must be wrong with our data or with these males,” Jędrzejewski said.
The largest cat in the Western Hemisphere, jaguars are found across 18 countries, from Argentina to Mexico. They live in a wide variety of habitats, from swamps to forests, and are opportunistic predators, feeding on more than 85 prey species. Aside from lions (Panthera leo), which live in groups called prides, and male cheetahs (Acinonyx jubatus), which sometimes form coalitions, all other cats were long believed by researchers to be solitary, including jaguars. While that’s still largely true of jaguars, scientists are now finding important exceptions, like M9 and M25.
From 2013 to 2018, camera trap photos showed the pair engaged in a range of classically collaborative behaviors, such as walking and marking territory together. On one occasion, one male mated with a female while the other male was nearby. M9 and M25 gradually expanded their territory, elbowing out at least six resident males, and subsequently mating with the females in the area.
Collaboration (of a different kind) revealed that similar behaviors, although still rare, had been observed by researchers in multiple areas in the Llanos and the Pantanal. The study’s multinational research team pooled data from five study sites and found that out of a total of more than 7,000 records of male jaguars, 70 included cooperative behaviors such as jointly walking and marking territory, sniffing each other’s faces, chasing transient males, and sharing carcasses.
By contrasting these areas of the Pantanal and Llanos with 13 other study sites across the jaguar’s range, where scientists had not recorded such behaviors, and using previously published data on lions and cheetahs, the researchers were able to shed light on how high female density and prey concentration may drive social behavior in jaguars and other felids. The authors suggest that in these prey-rich areas, males may form coalitions to increase their access to females.
“I think, prior to our research, there was an established belief that the sociality found in lions and cheetahs is unique among felids, it is genetically based, and appeared as a result of the different evolution of the two species,” Jędrzejewski said.
Both the Llanos and the Pantanal are exceptionally rich wetlands. Caimans, capybaras, turtles and fish thrive in the water, while other prey such as peccaries and livestock abound on land. That abundance leads to female jaguars having small and overlapping territories. Therefore, by banding together, males may increase their chances of taking over these areas and defending their access to mating with resident females. In other areas of the jaguar’s range, those conditions — the concentration of prey and subsequently females — don’t generally occur, so coalitions may not form.
“Our research shows that while the genetic factor and evolutionary histories are certainly important, under certain environmental conditions other species can also develop more complex social interactions,” Jędrzejewski said.
Study co-author Allison Devlin, deputy director of the jaguar program at Panthera, the global wild cat conservation organization, said the discovery points to the benefits of having long-term studies with multiple types of data, and adequate protection so that species can thrive.
“It shows the value of having long-term camera tracking, movement ecology data and direct observations through citizen science,” she said. “And from that we’re able to see that if you have a relatively stable jaguar population, healthy prey base, and protection for the species, we can start seeing these more natural behaviors, and start understanding some of the interactions that a solitary species might have.”
Jaguars are classified as near threatened on the IUCN Red List, and have lost 50% of their historic range. The greatest threats remain habitat loss (from deforestation and conversion of land to agriculture) and retaliatory killing over livestock predation.
In 2018, jaguar range nations and NGOs, including Panthera, launched the Jaguar 2030 Roadmap, a plan to “strengthen the Jaguar Corridor by securing 30 priority jaguar landscapes by 2030” and link these core populations with “jaguar-friendly” areas to allow genetic mixing across the entire range. The plan also includes working with ranchers to keep livestock safe from jaguar attacks, making sure local communities benefit from ecotourism, and more. “It’s not just within protected areas, it’s a mosaic of different working landscapes,” Devlin said.
In Hato Piñero, the state-owned cattle ranch where the male coalition of M9 and M25 roam, jaguars are protected, according to Jędrzejewski. But in other places in the Llanos, jaguars are often killed in retaliation for livestock losses. Jędrzejewski said high turnover of jaguars due to these killings means there is little chance that coalitions can become established, and added he hopes the study will also draw attention to the need to protect jaguars and their habitats.
“[The Llanos] is a beautiful place,” he said, “an area with big marshes, wet and dry forests … Every piece is different. There is a huge amount of food in the water — turtles, capybaras, caimans … In the dry season, they concentrate in pools, and the jaguars, especially the females with cubs, take advantage of this. In the evenings you can go by car and watch many animals, including, from time to time, jaguars.”
Jędrzejewski, W., Hoogesteijn, R., Devlin, A. L., Tortato, F., Concone, H. V. B., Azevedo, F., … & Schmidt, K. (2022). Collaborative behaviour and coalitions in male jaguars (Panthera onca)—evidence and comparison with other felids. Behavioral Ecology and Sociobiology, 76(9), 121. doi:10.1007/s00265-022-03232-3
Banner image: In the Hato Pinero study site in the Venezuelan Llanos, two adult males, M9 and M25, formed a multi-year partnership. Here they are photographed when expanding their territory to the northeast, subsequently displacing the previous resident male. Image by Wlodzimierz Jedrzejewski.