Birds exposed to Chernobyl radiation have smaller brains.

Researchers have determined that birds in Chernobyl have brains that are 5% smaller than average.

There are several theories as to why this may be.  It is possible that the lingering radiation from the nuclear disaster causes oxidative damage to the brain.  Another theory is that the birds may be not developing well because there is less food available to them in this area.

You can read the whole story on the BBC Earth News site.