Birds lay eggs of surprising variety, and scientists have long wondered why. Could it be that certain shapes protect eggs from shattering? Or perhaps allow them to fit snugly in a nest?

What is smaller than the width of a dime and weighs less than half a gram? That would be the egg of an Allen’s hummingbird. This tiny bird lays tiny eggs and lives in tiny nests. We are fortunate ...

"The different colors, or the presence of spots or speckling, come down to the genetics of the bird," he says. "Leghorn chickens (which make up most of the commercial egg industry in the U.S.) lay ...

The oldest known wild bird in the world has laid an egg at ... had returned to the atoll in the Pacific Ocean to lay and hatch eggs since 2006. Laysan albatrosses mate for life and lay one egg ...

Brood parasitic birds lay their eggs in the nests of others, sparing themselves the expense of rearing their own young. The resulting coevolutionary arms race includes sophisticated defenses by ...