BirdNote Daily

A frantic cacophony of loud, rapid birdcalls tells other birds there’s a predator on the prowl. It’s called “mobbing” as birds clamor and dart — back and forth — at the threat. An ongoing study of mobbing and other bird warning behavior suggests that some birds listen in on the warnings of other birds. A wave of warning calls spreads from one hillside to another at more than 100 miles per hour. So vulnerable birds may be clued in to the movements of predators like this Northern Pygmy-Owl, giving them time to take cover. Learn more at BirdNote.org.

The structure and delicate softness of its feathers allow a Barn Owl to approach its prey almost without sound. The Barn Owl's ability to locate prey by sound, even when concealed by snow or leaves, is the most precise of any animal yet tested. This young Barn Owlet is about five weeks old and actually weighs more than its parents. During and after the fledging period, it will gradually lose weight, as it learns to hunt for itself. Be sure to watch the video of an owl hunting. Learn more at BirdNote.org.

The drumming of the male Ruffed Grouse is one of the most evocative sounds of the North American forest. Familiar as these accelerating burps are to hunters and hikers, the origin of this bizarre sound was long a mystery. It took the advent of wildlife cinematography to solve the riddle. In the spring of 1929, Cornell University’s Arthur A. Allen filmed a drumming Ruffed Grouse. Frame-by-frame analysis showed the bird’s wings were striking nothing but air — hard and fast enough to produce popping sounds that ran together into the whirring drum. Learn more at BirdNote.org.

Polar bears use Arctic sea ice to hunt seals, but a warming Arctic means the bears have to return to land earlier in the year. Their arrival coincides with droves of birds sitting on eggs. A single clutch of eggs isn’t enough to satisfy a bear, so they go from nest to nest, sometimes eating their way through a colony. Scientists designed a bear-proof nest case to protect Black Guillemot eggs. Learn more at BirdNote.org.

After hatching, baby robins spend up to 15 days in the nest. By July, many young American Robins have left the nest, or fledged. But they aren't ready to make it entirely on their own yet, and they follow their parents around, learning to fend for themselves. Outside of the breeding season, robins tend to form large flocks, often feeding on berries and fruits. Learn more at BirdNote.org.

The Tui is one of New Zealand’s most remarkable birds, intelligent and with iridescent feathers. Its down-curved beak fits perfectly into native flowers. But the Tui is best known for its voice. Each Tui’s complex song is slightly different, a colorful mix of musical notes and offbeat sounds. It’s one of the few birds that can imitate human speech — and even accents. Learn more at BirdNote.org.

Football and baseball players sometimes wear eye black to reduce glare from the sun or stadium lights. According to scientists, some birds — including many shrikes, like this Northern Shrike — have evolved a band of black feathers across their eyes that helps in the same way. The black markings may also help the birds hunt and fool predators. Learn more at BirdNote.org.

Just a few weeks past the solstice, and the real heat of summer is yet to come. Some shorebirds are already on their way south, but most songbirds will be here for a while longer. What's the best time of day to look for them? Many birds are most active in the early morning, taking advantage of the abundance of insects at that hour. Midday heat sends people inside, and birds take a siesta, too. And then, both birds and bugs rev up again in the late afternoon. But hummingbirds and also gulls — including this Glaucous-winged Gull — forage all day long! Learn more at BirdNote.org.

Both this Eastern Towhee and the Spotted Towhee of the West sport a black or dark brown hood and back. And when they fly, their tails flash white. When a hawk gives chase, the towhee's flashing tail-feathers draw the predator's attention. Momentarily distracted, the hawk may come up with just a couple of tail feathers — as the towhee escapes into the underbrush. So if you see a towhee missing a couple of tail feathers, it may be that the flash of white — the distractive plumage — saved its life. Learn more at BirdNote.org.

Every bird species uses its wings a little differently, and some are specialized for highly efficient flight. But that means going without other abilities. Swallows and hummingbirds capture their food on the wing, but they can’t walk. Swifts, which are acrobatic in the air, can’t even perch. Yet they dazzle with the maneuverability made possible by their aerodynamic bodies. Learn more at BirdNote.org.