Chernobyl: maybe not a wildlife paradise after all

I've seen many articles over the last few years (this Popular Science article being just the latest) singing the praises of the wildlife around Chernobyl nuclear power station.
After Reactor #4 exploded and its radioactive core melted down on April 26 1986, spewing out about 400 times the radiation as the bomb that was dropped on Hiroshima, 350,000 people were permanently evacuated and a 2,600 km² exclusion zone was established around the plant. Thousands of animals died in the blast, and extensive areas of pine forests turned red and died overnight. Estimates of the accident's toll on human lives vary hugely.
But, in this newly unpopulated and unvisited area, nature eventually (actually, surprisingly quickly) reasserted itself, and many animals and birds took advantage of the absence of human interference. So, not surprisingly, it has become, over the last 33 years, a huge nature reserve, putting paid to early predictions that the area would become a wildlife desert for centuries. It is now inhabited by brown bears, bison, wolves, lynxes, Przewalski horses, and over 200 species of birds. In the last couple of years, some limited wildlife tourism has begun in the area, which some are touting it, apparently without irony, as some kind of new Eden.
A recent meeting of the main groups doing research in the restricted area confirmed the great biodiversity in the region, and reported that most animal populations appear stable and healthy, perhaps surprisingly so, with a general lack of major negative effects from the continuing radiation there. Some species have adapted, even in such a short time, like the frogs that have developed a darker skin colour than equivalent frogs outside the area (which may, or may not, be a kind of adaptation to the radiation), and some bird species tend to be a lighter colour than elsewhere, although it is not really known why.
However, not all reports are quite as positive as the Popular Science article. Canadian scientist Timothy Mousseau cautions that, if you start to dig a little deeper, a more disturbing picture emerges. One interesting and largely overlooked fact is that the radiation is not equally spread throughout the region, but there are still pockets of very high radiation right next to areas of much lower contamination, creating a kind of patchwork effect, for reasons that no-one seems to understand. Because of this, it is possible compare close populations of animals and assess the effects of radiation on them.
From Mousseau's research, it is clear that the radiation is in fact reducing fertility rates and population sizes. He also concludes that there is no evidence of any direct or successful adaptation to radiation. Birds in the more radioactive areas, for example, exhibit random changes in colouration (including albinism), genetic damage, increased rates of cataracts and tumours, smaller brains (linked to poorer survival rates), lower sperm counts, and reduced population sizes. And there is some evidence that these negative traits are being passed down to offspring, in some kind of unexplained genetic or epigenetic way.
So, not sounding quite so Eden-like after all.