Developing eggshells requires a key ingredient — calcium — in larger quantities than the female typically has in her bloodstream. Just how different bird species supply or store calcium for egg-laying isn’t fully known. While some species seek out extra calcium from their environment, many…

Most duck species court and form pair bonds in winter. In the icy waters of Vermont’s Lake Champlain, Common Goldeneyes are getting hot! This male is displaying his signature move, the “head-throw-kick,” to attract a mate. Goldeneye pairs now bonding throughout the US will migrate in early…

The word “dove” might make you think of an elegant bird symbolizing peace, while the word “pigeon” might bring up images of rowdy flocks of city birds. But there’s no formal distinction between doves and pigeons, only a linguistic one. In many languages, the birds are one and the same. The…

Juan Pablo Culasso is a nature recordist based in Colombia. Here, he describes how he uses a parabolic microphone to record a singing bird. Juan Pablo is blind, so he uses his hearing to pinpoint a small bird in dense vegetation.

A single Canada Goose has between 20 and 25 thousand feathers. Some are designed to help the bird fly or shed water. Many are the short, fluffy kind, the down that insulates the bird from the cold. Birds survive in sub-zero weather by fluffing their feathers, creating layers of air and…

The hoots of the Greater White-fronted Goose inspired a nickname, the “Laughing Goose.” A little smaller than Canada Geese, these gray-brown birds are named for the band of white around the base of their pinkish-orange bills. Greater White-fronted Geese are strong, athletic fliers. When…

For birds and other animals with good natural insulation, winter provides a striking benefit as they scavenge. Bacteria function very slowly or not at all in the cold, preventing dead bodies from rotting. In northern latitudes, ravens and other scavenging birds take advantage of winter's…

The secret to birds’ flight starts with the shape of their wings. They’re curved in a way that causes air to flow more slowly under the wing than above it. That creates an area of low pressure just above the wing that pulls the bird up into the sky—a force called lift. Airplane wings are…

Gentoo Penguins live in the frigid waters of the Atlantic. Only recently have scientists begun to unravel why penguin feathers don’t freeze. An electron microscope revealed tiny pores on the feathers that trap air, making the surface water repellent. This feature, plus a special coating…

The Cuban Giant Owl, now extinct, was 3½ feet tall and weighed 20 pounds — the largest of all known owls. It had very small wings, running after its prey on long, powerful legs. Similar large owls, with long legs and small wings, have been unearthed in places as disparate as Georgia and…