Once nesting season ends, swallows know it's time to party! Whether they nest as single pairs or in large colonies, both adults and juveniles now gather on electrical wires by the dozens, socializing before they migrate. Migrating by day – and foraging for insects as they go – swallows…

Brown-headed Cowbirds have a sneaky approach to parenthood. They lay eggs in the nests of other songbirds, and the songbird hosts often raise the cowbird chick as their own. It’s called nest parasitism. But sometimes the hosts throw out the odd-looking egg. And when that happens, the…

Hummingbirds use their long tongues to sip nectar from flowers. They’re able to roll their tongues into a tube-like shape. Since the 1800s, scientists thought those tongues worked through capillary action, like how water instantly rises into a straw in a full cup. But when scientists spent…

Once abundant around San Francisco Bay, the Ridgway’s Rail — formerly known as the California Clapper Rail — is now endangered. In the 19th Century, unregulated hunting plundered the species. In the 20th Century, rampant development reduced salt marsh habitat by 85%. But in the 21st…

Let’s talk about nests. Every spring, robins build their cup-shaped nests using grass and mud. Orioles weave a hanging sack. It’s hard work, and yet once the chicks fledge, the structures probably won’t be reused. But bigger birds, such as herons, hawks, and eagles, often reuse a nest for…

The American Crow’s rattle call is uncommon, and researchers aren’t sure what it means. It could be a gathering call, a predator alarm, or a call between mates. But if you hear it, you might think it sounds like cackling laughter. However, no one has identified a crow noise that indicates…

Broad-tailed Hummingbirds are small but hardy creatures built for life in the mountains. They survive freezing cold nights by slowing their heart rate and metabolism. And they perform a death-defying stunt for potential mates. Male Broad-tailed Hummingbirds begin their performance by…

At a glance, swallows and swifts, both graceful fliers, look much alike. But swifts — like this Chimney Swift — have longer, slimmer wings and short bodies, enabling them to glide for long periods. Their glides are punctuated by rapid, stiff bursts of wing-beats. Swallows, on the other…

There are promising signs that a native Hawaiian bird called the ulūlu is on the way to recovery. Also known as the Millerbird, this small gray songbird nearly disappeared when invasive species including rabbits destroyed most of their habitats on the island of Laysan in the early 1900s…

Although some of the Turkey Vulture's habits may evoke our disgust, these remarkable birds also inspire our awe. With wingspans approaching six feet, Turkey Vultures ride currents of air to make their spring and fall journeys, and to cover the miles of their home range in summer. Gliding…