The Chernobyl accident of 1986 released vast quantities of radioactive materials and significantly contaminated about 200,000 square kilometers of land. The Chernobyl Forum Report, an initiative of the International Atomic Energy Agency, suggested that the effects of radiation on wildlife were negligible relative to the impacts of human habitation, but this position was based on the very limited data available prior to this 2006 report. The wildlife of this region has been the subject of extensive study since 2005; since then, research has found that many birds, insects, spiders, and mammals show significant declines as a probable consequence of exposure to radionuclides. The best-studied group, birds, shows a 50 percent decrease in species richness and a 66 percent drop in abundance in the most contaminated areas compared to areas with normal background radiation in the same neighborhood. In addition, mutation rates and developmental abnormalities are dramatically higher, and survival rates and fertility are lower, in regions of moderate to high contamination. These findings challenge reports in the popular media and the conclusions of the Chernobyl Forum Report and are of relevance today, given recent interest in returning contaminated lands to agriculture use and the renaissance of the global nuclear power industry.