Jaguar female population drops 77% in Amazon reserve

A scientific study conducted by the Mamirauá Institute in partnership with Panthera has revealed a 77% decline in the female jaguar population within the Mamirauá Sustainable Development Reserve in the Amazon between 2005 and 2022. While the total number of jaguars in the region has remained relatively stable at approximately 610 individuals, the drastic reduction in females poses a significant threat to the species' ability to reproduce and renew the local population.

Researchers noted an increase in male density during the same period. This imbalance may be driven by hunting pressures that remove resident males, allowing new males to migrate into the territory. These incoming males often engage in infanticide—killing existing cubs to induce females to enter estrus sooner—which further reduces the recruitment of new females. Additionally, experts are investigating the role of infectious diseases, such as West Nile virus, Saint Louis encephalitis, canine distemper, and leukemia, as potential contributing factors to the decline.