Jaguar numbers in the Amazon Rainforest may be higher than previous estimates, according to a new large-scale study that offers the most comprehensive population snapshot to date.
Using camera-trap images of jaguars (Panthera onca) across the Brazilian, Colombian, Peruvian and Ecuadorian Amazon, researchers calculated an average density of three jaguars per 100 square kilometers (about eight per 100 square miles) in 22 protected areas. This is triple the density estimate the IUCN, the global wildlife conservation authority, currently notes for Amazonian jaguars.
“I wouldn’t risk saying that the entire Amazon has the average density of jaguars we found,” study lead author Guilherme Alvarenga, an ecology researcher at the University of Oxford, told Mongabay by phone. “But our results indicate that we likely have more jaguars per square kilometer than the [IUCN estimate] showed.”
Each jaguar’s pattern of spots and rosettes is unique, like a human fingerprint, enabling researchers to identify 389 individuals from camera-trap photos. Based on this, they estimated more than 6,300 jaguars in the 2.5% of the Amazon they assessed. About 62% of the biome is under some form of conservation, but much of it has never been surveyed for jaguars.
Antonio de la Torre, director of Mexico’s Jaguares de la Selva Maya program and author of the study that informed the IUCN estimate, said the new findings show that Amazonian jaguar densities are “higher than previously thought” and provide important conservation insights.
“When we conducted the study published in 2018, data on jaguar densities in the Amazon were very limited,” de la Torre told Mongabay by email. “This collaborative study is incredibly valuable, as it provides crucial data that will help refine population projections.”
Global jaguar numbers may be closer to higher-end estimates around 173,000 individuals, the findings suggest, rather than the IUCN’s conservative estimate of 64,000.
While the jaguar is listed as near threatened on the IUCN Red List, the Amazonian jaguar is the only subpopulation listed as being of least concern. The species has disappeared from half of its historical range, running from the southern U.S. to central Argentina, leaving the Amazon as its last major stronghold. All other subpopulations are either endangered or critically endangered.
“Jaguar populations serve as an indicator of the quality of the environment, which is useful,” Alvarenga said. In the Mamirauá Reserve, a floodplain forest along the Amazon River, densities neared 10 per 100 km2 (26 per 100 mi2), three times the average. But in the Cuieiras Reserve, an area with poor soil quality north of Manaus, the Amazon’s largest city, there were 20 times fewer jaguars.
“First, you need to map how these populations are distributed,” Alvarenga said. “Once you understand that, you can plan more effective actions in areas where numbers are declining, or habitat quality is not as good, to prevent them from disappearing from those places.”
Banner image: Jaguar siblings in Poconé, Brazil. Image by Bernard Dupont via Flickr (CC BY-SA 2.0).
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