Chernobyl: Wildlife overtaking the wasteland?

People living in the area around the Chernobyl nuclear power plant had to leave their homes as a result of the 1986 disaster and radioactive fallout from reactor 4. A 30-kilometer (19-mile) exclusion zone was established around the plant. Significant radioactivity is still present. And although it is regarded as the most contaminated ecosystem on earth, life still thrives there.

Before the disaster, some 2,000 people lived in Tulgovichi, a village within the exclusion zone. Today, fewer than 10 people call this place home. So, how does a landscape change if it is suddenly abandoned by humans?

Various animals like these bison have been seen on the site - but the question of whether biodiversity is truly thriving in the area is difficult to answer. Scientists make various claims. Some argue that high-intensity radiation led to a decline in numbers of some spider and insect species - especially in the more contaminated area, within a 10-kilometer radius around the nuclear plant.

Elk have likewise been observed at the site, as have wild wolves, eagles and horses. Some scientists have questioned studies indicating less wildlife, saying their visits to the area show animal numbers there at least equal to those in similar habitats outside the zone - irrespective of radiation levels. To date, there has been no quantitative comparative study assessing wildlife.

As radioactivity is known to damage DNA, which codes genetic information, it's no surprise that animals in the area have been found with a higher frequency of tumors and physical abnormalities - such as birds with deformed beaks. That said, some bird species are reported to have adapted to the radioactivity by producing higher levels of antioxidants that appear to protect against genetic damage.

Researchers have also investigated whether radiation has an impact on animal behavior. Spiders given caffeine or other drugs are known to lose their ability to make geometrically perfect webs.Timothy Mousseau from the University of South Carolina has been capturing Chernobyl spiders' webs on camera to analyze whether radioactivity might affect them in similar ways.

Radioactivity can also have less-visible impacts on living beings inside the exclusion zone. To unearth them, researchers had to start digging. When they assessed the abundance of soil-bound animals, they found earthworms, diplopods and oribatid mites to indicate the earliest stage of ecosystem recovery following radioactive fallout.

Although it might sound cynical, the nuclear disaster of Japan's Fukushima opens another "laboratory" for scientists to investigate how biodiversity reacts to radioactivity. Japanese researchers, for example, have already proved that mutations in the pale blue butterfly's genome led to deformed wings or bodies.