When vertebrates moved onto land, long ago, some of them eventually became airborne, way after the insects did. There are ...

but that the sounds are different for the two subspecies." Although it’s not uncommon for birds to communicate with each other by flapping their wings to make a desired noise, this was a particularly ...

However, when looking at the correlation across legs and wings, results are different: Bird species show little to no correlation, whereas bats show strong correlation. This means that ...

This bird made hawk-watching famous ... but no malar stripe; shorter, barred wings and much longer tail give a different shape.

In flight, wings appear translucent. Adult: one molt per year, but fresh fall adults look very different from summer birds. On freshly molted birds, black plumage has white spots all over ...