In Texas, Pennsylvania, and elsewhere, people have reported seeing Northern Cardinals that are red on one side and brown on the other, indicating that a bird is half male and half female. This anomaly occurs in other species of birds, as well, not just cardinals. Insects, too! Scientists…

This American Kestrel evolved to nest in tree cavities or small caves in cliffs. We humans have made life difficult for kestrels. Development has shrunk the open spaces they need. We’ve cleared away dead trees they rely on for nests and sprayed pesticides that eliminate the insects the…

Many woodpeckers chisel out deep cavities in tree trunks in order to lay their eggs and raise their brood. The cavities hollowed out by the birds vary in size, depending on the species of woodpecker. The chamber of a tiny Downy Woodpecker descends about a foot from the opening, while the…

Male Great Egrets have special long feather plumes called aigrettes, which they use in courtship displays in the spring. These beautiful big birds were nearly hunted to extinction for these special feathers, which were used to adorn ladies’ hats. The plight of the egret spurred people to…

Tiny Marsh Wrens live in wetlands, usually within cattails, reeds, or bulrushes. After choosing his territory, the male weaves up to 15 dome-shaped shells, lashing together cattails, grasses, or reeds. These are called "courting" nests. Then, sitting high atop a perch in the marsh, he…

It's dawn in a western marsh in mid-summer, and man! Those birds are singin'! The males of more than a dozen species are staking out their territories and attracting mates. One of the noisiest of all is the Red-winged Blackbird. He sings not to attract just one mate, but to gather a whole…

Just because a young bird appears to be alone – whether on the ground or squawking loudly from a bush or tree – doesn't necessarily mean it is sick or injured. In June, young birds, including this juvenile Northern Flicker, are leaving their nests. And most likely, a parent is near-by and…

A male American Golden-Plover proclaims its nesting territory with an aerial display known as the "butterfly flight." After flying up 50 feet, the plover switches to slow motion, raising its wings languidly until the wingtips nearly touch over its body, then lowering them gradually until…

The Northern Hawk Owl is one of the least studied and least known of all birds in North America. Northern Hawk Owls are owls, but they share several traits with hawks and falcons: A streamlined body shape, daytime hunting habits, and stiff wing feathers for daytime hunting. (Owls that hunt…

Some gulls and terns may show a glowing pink color, similar to that of flamingos and spoonbills. This pink color comes from pigments in the birds' food called carotenoids. These gulls and terns are able to convert these naturally occurring pigments to hues that may enhance their success at…