The number of eggs a bird lays — its clutch size — varies greatly among species. You might think every species should simply lay lots of eggs because that would increase the odds of more young birds ...

CHICAGO — It’s springtime, and the birds are chirping as they begin to build their nests. Researchers say the hands-on clock is turning back, though it happens like clockwork each year. Many species ...

A once-extinct bird is laying eggs in the wild for the first time in nearly 40 years. Sihek, a now-endangered bird returned to the wild in 2024, has laid wild eggs in its new home in Hawaii, according ...

Nests are generally thought of as a bird’s home, but it is more appropriate to consider them a nursery for raising baby birds. S.K. Winnicki, a Ph.D. candidate in avian evolutionary ecology at the ...

Q. I saw a photo of different kinds of bird eggs and noted not only the obvious, that smaller birds lay smaller eggs, but also that some bird eggs are elongate, whereas others are more rounded. What ...

Black birds with a greenish sheen and brown heads sometimes visit my yard during spring migration. These are male brown-headed cowbirds, and they often arrive in mixed flocks of red-winged blackbirds ...

One of the world’s most famous birds has returned to her nesting site. Wisdom, the 75-year-old albatross is known as the ...