Using data from 25 countries, scientists estimate that European bird populations have declined by more than 420 million over 3 decades, with some of the biggest losses coming from common species such as house sparrows, skylarks, and starlings. The Guardian reports that some rarer birds have seen their numbers increase thanks to conservation efforts, but the more robust species have not received the same attention and have suffered for it. Scientists say the declines are largely caused by habitat loss and that broader, more comprehensive approaches will be required to target these common species because of their widespread distribution and abundance.