Once a month, Mohamed Esimbo Matongu leaves his home in the western Congolese city of Mbandaka and hunts for wild animals.

Though he works for a government agency, he says he needs the income from selling most of what he kills to provide for his family. But bushmeat hunters like him are emptying Central Africa's forests at a high rate, researchers say. "When I was a teenager, I had to travel no more than 10 km (6 miles) upriver to find animals. But now I have to go as far as 40 km to come across a decent hunting ground," said 61-year-old Matongu.

Mohamed checks a trap in the forest.