{"id":80174,"date":"2022-01-03T22:30:00","date_gmt":"2022-01-04T07:30:00","guid":{"rendered":"https:\/\/www.juneauempire.com\/news\/on-the-trails-diving-into-birds-underwater\/"},"modified":"2022-01-03T22:30:00","modified_gmt":"2022-01-04T07:30:00","slug":"on-the-trails-diving-into-birds-underwater","status":"publish","type":"post","link":"https:\/\/www.juneauempire.com\/news\/on-the-trails-diving-into-birds-underwater\/","title":{"rendered":"On the Trails: Diving into birds underwater"},"content":{"rendered":"

By Mary F. Willson <\/strong><\/ins><\/p>\n

For the Juneau Empire<\/p>\n

<\/em><\/ins><\/p>\n

Many kinds of bird regularly forage for prey underwater.<\/p>\n

These birds have a variety of ways of doing so and adaptations to match. Life in the water is very different from life in the air.<\/p>\n

The first hurdle to overcome is simply getting there. Some species start from the water surface. A few are able to just sink below the surface by decreasing their buoyancy: small grebes and anhingas do this by compressing the plumage (thus pushing air out) and exhaling. Others tuck their heads and kick with their webbed or lobed feet (e.g., mergansers, goldeneyes, buffleheads, most cormorants, loons, and some grebes) or flip their wings (murres, long-tailed ducks, dippers). Those that surface-dive a lot (e.g., loons) typically have legs set well back on the body, making them awkward on land.<\/p>\n

Another way to get underwater is from above the surface.<\/p>\n

Dippers often dive into a stream from a rock or low-hanging branches not far from the water surface. Kingfishers may plunge from several meters above the surface, folding the wings closer to the sides. Brown pelicans can dive from a height of twenty meters, extending the neck and angling the wings back, making a more streamlined shape. The grand champion divers may be seabirds called gannets and boobies; they can start a dive from almost a hundred meters up, turning the body into a sleek dart, with the neck well-extended and the wings held back close to the body. The dives can reach a speed of sixty mph; to protect the bird from the resulting high impact, the skull is reinforced and subcutaneous air sacs on the chest and sides cushion the jolt.<\/p>\n