Groove-billed Anis gather in loose groups. And with good reason. They nest communally. As many as four or five pairs of birds may use one nest, a bulky cup of twigs lined with fresh leaves. When the dominant female ani begins to lay her own eggs, the other females lay simultaneously. Up to…

Birds’ four-chambered hearts run larger than those of mammals, relative to body size, and they are coupled with extremely efficient cardiovascular systems. The energy demands of flight require these adaptations. An exercising human has a heart rate around 150 beats per minute. In contrast…

Collective nouns are a mixture of poetry, alliteration, and description. Victorians often made up creative names for groups of birds, as a parlor game. Many names bring a vision of the birds instantly to mind. How about this spring of teal? These are Green-winged Teal. So what would a…

Birds that historically nested in the cavities of dead trees are finding natural nest holes harder to come by — but people can help. Many of these species will make use of a nest box in parks or near people’s homes. Learn how to build nest boxes tailored to a species of your choice at…

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.

In the depths of winter, when open water is frozen over, it can be challenging for birds to stay hydrated. Some birds eat the frozen water all around them. Cedar Waxwings catch snowflakes in mid-air. Black-capped Chickadees drink from dripping icicles. Plenty of other birds scoop up fresh…

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…