Natural selection at its most powerful winnowed certain finches harshly during a severe drought in 1977. That year, the vegetation withered. Seeds of all kinds were scarce. The small, soft ones ...

A cinnamon warbling-finch was spotted a few days later, but researchers said it was impossible to determine if it was the same bird recorded ... near Paraguay’s border with Bolivia The Dry ...

There are now at least 13 species of finches on the Galapagos Islands, each filling a different niche on different islands. All of them evolved from one ancestral species, which colonized the ...