Amazon Jaguars Face Uncertain Future as Males Outnumber Females

Researchers at the Mamirauá Reserve in Brazil's Amazon rainforest have made a surprising discovery about jaguar behavior. The reserve is home to one of the highest densities of jaguars on the planet, with up to 15 individuals per 100km2. What's more, these big cats have adapted to living and hunting in trees during the four-month flooding season.

The researchers analyzed 17 years' worth of camera-trap data and found that while the overall population remains stable, there has been a significant shift in gender ratios. Between 2005 and 2022, female jaguar numbers decreased by 77%, while male numbers increased. This is concerning, as high numbers of males can lead to infanticide, where new males kill young cubs so they can mate with females.

The researchers believe that external males may be entering the population from other areas, and that hunting by local people may be contributing to this trend. They note that climate change could also be a factor, but more research is needed to determine its impact. The findings have sparked concerns about the long-term health of the jaguar population in the reserve.