Nearly 30 years after the Chernobyl nuclear disaster in Ukraine, elk, deer, boar and wolves are thriving in the exclusion zone deserted by humans, researchers have reported in an international study.

The study, published on Monday in the journal Current Biology, shows there are at least as many of these mammals inside the 4,200-square-kilometer perimeter around the nuclear plant as in uncontaminated nature reserves.

Researchers counted the animals using aerial observations of the zone that was devastated by an explosion in one of the plant's nuclear reactors in April 1986.