It was twenty years ago today that a reactor exploded at Chernobyl's nuclear power plant. Thirty-one people died immediately from exposure to the radioactivity, and estimates of the total number of people expected to die from Chernobyl-related cancer range from the UN's 9,300 to Greenpeace's 93,000. 77,220 square miles were contaminated, and 300,000 people were permanently evacuated from the area.

In the absense of human occupants, however, the 19-mile exclusion zone around the reactor has become home to a thriving wildlife population. According to an article on the BBC News website, existing populations have been multiplying, and species long gone from the are have been returning.

There may be plutonium in the zone, but there is no herbicide or pesticide, no industry, no traffic, and marshlands are no longer being drained.

According to the same article, the wild boar population multiplied eightfold between 1986 and 1998, along with increases in wolves, deer, elk, otters, foxes, hares, cranes, and others. Lynx, eagle owls, and possibly bears have returned to the area after decades of absence (or centuries, in the case of the bear). The region has even become home to animals never seen in the area. From an Animal Planet News article:

Take for example the famed Przewalski's horse, believed to be the only true modern descendant of the wild horse. In 1998, 17 of them were introduced to the area. Today officials who accompany visitors to the zone say the steeds number between 80 and 90, and the area around Chernobyl is one of the few places in the world where they still roam free.

What an eerie image. It somehow brings to mind John Hersey's description of Hiroshima in unnatural bloom a month after the bombing:

Over everything... was a blanket of fresh, vivid, lush, optimistic green; the verdancy rose even fromt he foundations of ruined houses. Weeds already hid the ashes, and wild flowers were in bloom among the city's bones. The bomb had not only left the underground organs of plants intact; it had stimulated them.

There's still some debate about the level of radioactivity presently in the animals. According to the BBC article, many of the animals are still "too radioactive for humans to eat safely," but otherwise healthy. The BBC quotes a radioecologist named Sergey Gaschak, who says that although there is evidence of DNA mutations, they haven't affected the animals' physiology or reproductive ability. "The mutants never resembled the monsters described in the media and all died out quickly," the same Gaschak says in the Animal Planet article.

But an article in National Geographic quotes two scientists, Anders Moller from the University of Peirre et Marie Curie and Tim Mousseau from the Unversity of South Carolina, who belive that certain species of birds have been adversely effected. They found an increase in partial albinism (white feather tufts) in Chernobyl's barn swallows, and annual survival rates of only 15 percent or less, compared to 40 percent in Italy.

The scientists are also concerned that the mutated birds will pass on their abnormal genes to the global population. "In the worst case scenario these genetic mutations will spread out, and the species as a whole may experience enhanced levels of mutation," Mousseau said.

At a memorial service for the victims of Chernobyl, Ukrainian President Viktor Yuschenko said "Chernobyl must not be a mourning place; it must be a place of hope." The wildlife thriving in the exclusion zone offers a deceptive vision of such hope. Perhaps that makes it easier to stomach Yuschenko's interest in expanding Ukraine's nuclear energy use.