Hunting behind steep drop in animal numbers in tropics: report

Hunting poses a major threat to mammals and birds in tropical regions near population centers and roads, according to new research published Thursday in the US journal Science.

An international team of researchers found that mammal and bird populations dropped on average by 83 percent and 57 percent, respectively, in zones situated seven to 40 kilometers (four to 25 miles) from access points such as roads or villages.

The study also showed that commercial hunting more heavily impacted animal populations than hunting for food.

A number of factors drive declining animal populations, like deforestation and habitat loss. But this study was the first to show the large-scale impact of hunting on a wide range of animal species, according to the researchers.

They combined 176 studies to quantify declines of 254 mammal species and 97 bird species across the tropics in Central and South America, Africa and Asia.

Rising demand for wild game meat has depleted populations of large species in close proximity to villages, the researchers said, meaning hunters were traveling greater distances in search of quarry.

"Strategies to sustainably manage wild meat hunting in both protected and unprotected tropical ecosystems are urgently needed to avoid further defaunation," said study leader Ana Benitez-Lopez of Radboud University in Nijmegen, the Netherlands.

"This includes monitoring hunting activities by increasing anti-poaching patrols and controlling overexploitation via law enforcement."