Under these drastically changing conditions, the struggle to survive favored the larger birds with deep, strong beaks for opening the hard seeds. Smaller finches with less-powerful beaks perished.

Large raptors, like red-tailed hawks, bald eagles and great horned owls, survive on prey they cant necessarily swallow whole. These meat-eating birds, have sharp, hooked beaks that pierce ...

How do you know that finches' beak depth is heritable? You can see from Figure 2 that there is a correlation between the parents' and offsprings' beak size. How did the finch population change ...

The different finch species on the islands are closely related to each other, but show wide variations in beak and body size and feeding behaviour. In particular, changes to the size and shape of the ...

It is endowed with birds that have beautiful covers ... and both are coloured in a bold combo of red and black. They use this beak to “skim” the water’s surface while flying, snapping ...