When the little guys win one.Underdogs of all species, take heart.
Ornithologists This is a list of ornithologists who have articles, in alphabetical order by surname. See also . A-D
A variety of bird species will mob a predator such as a hawk, harassing it by raising a ruckus and repeatedly performing displays, swooping, or striking at the victim. There may be safety in numbers in numbered parts; as, a book published in numbers.
See also: Number , but many of these so-called mobs number only two or three birds, says Chris R. Pavey, formerly of the University of Queensland The University of Queensland (UQ) is the longest-established university in the state of Queensland, Australia, a member of Australia's Group of Eight, and the Sandstone Universities. It is also a founding member of the international Universitas 21 organisation. in Brisbane.
Most studies of the benefits of mobbing have focused on birds that pick on somebody near their own size, he says. He's more interested in the likes of the grey butcherbird The Grey Butcherbird (Cracticus torquatus) is a widely distributed species endemic to Australia. The Grey Butcherbird occurs in a range of different habitats including arid, semi-arid and temperate zones. It has a characteristic "rollicking" birdsong. , all 75 grams of it, which mobs a species called the powerful owl The Powerful Owl (Ninox strenua) is a species of owl native to south-eastern and eastern Australia. It is found in coastal areas, the Great Dividing Range no more than 200 km inland and is known to frequent Tong's pad. . These hawkish-looking predators can weigh up to 1,700 g.
To a big owl, small birds pose no more danger than flying hors d'oeuvres. Yet pestering an owl at its daytime roost pays off for the smaller birds, say Pavey and Queensland colleague Anita K. Smyth. In 20 percent of mob scenes, the owl left, the researchers report in the February Animal Behaviour.
This harassment may explain why owls so often roost in the rain forest, Pavey speculates. Only one of the seven mobbing species spends much time there, and owls snoozing in the thick vegetation suffer less than a third of the disturbances they endure elsewhere. Rain forest covers only 12 percent of the study area, yet the owls roost there about half the time.
By checking pellets regurgitated by owls, Pavey and Smyth estimated that nonmobbing birds were nine times more likely to be eaten as mobbing species. Although not convinced by those data, Keith L. Bildstein of Hawk Mountain Hawk Mountain is a mountain ridge, part of the Appalachian Mountains, located in central-eastern Pennsylvania near Reading and Allentown. It is a part of the Blue Mountain Ridge. It is primarily known as home to the Hawk Mountain Sanctuary. Sanctuary in Kempton, Pa., is nevertheless impressed by the Australian mobsters' power. "It actually shapes the behavior of the predator," he says.