Berlin (dpa) - The global stocks of many animal species in forests have more than halved according to a study in recent decades.

Between 1970 and 2014, the 455 populations studied shrank by an average of 53 percent, according to the environmental foundation WWF, citing its own analysis. Particularly affected are the tropics and the Amazon rainforest. The main reason for the development was called "man-made habitat loss".

The analysis also mentions examples in which species could recover. Gorillas in Central and East Africa, for example, assume that the number will rise again as protective measures have contributed to this.

Overall, the report included data from 268 vertebrate species that live in forests or are completely dependent on them. The work involved the UN World Monitoring Center for Nature Conservation and the Zoological Society of London.