Friday, September 14, 2012

scrub jays react to their dead...,



UCDavis | Western scrub jays summon others to screech over the body of a dead jay, according to new research from the University of California, Davis. The birds’ cacophonous “funerals” can last for up to half an hour.

Anecdotal reports have suggested that other animals, including elephants, chimpanzees and birds in the crow family, react to dead of their species, said Teresa Iglesias, the UC Davis graduate student who carried out the work. But few experimental studies have explored this behavior.

The new research by Iglesias and her colleagues appears in the Aug. 27 issue of the journal Animal Behaviour.

Western scrub jays live in breeding pairs and are not particularly social birds.

“They’re really territorial and not at all friendly with other scrub-jays,” Iglesias said.

Working in the backyards of homes in Davis, Calif., Iglesias set up feeding tables to encourage visits from the jays. Then she videotaped their behavior when she placed a dead jay on the ground. She compared these reactions with the birds’ behavior when confronted with a dead jay that had been stuffed and mounted on a perch, a stuffed horned owl, and wood painted to represent jay feathers.

On encountering a dead jay, prostrate on the ground, jays flew into a tree and began a series of loud, screeching calls that attracted other jays. The summoned birds perched on trees and fences around the body and joined in the calling. These cacophonous gatherings could last from a few seconds to as long as 30 minutes.

Jays formed similar cacophonous gatherings in response to a mounted owl, but ignored painted wood. When confronted with a mounted jay, the birds swooped in on it as if it were an intruder.

Jays typically gathered within seconds of the first bird calling, Iglesias said. If they did not, the first jay would often fly higher into a tree, apparently to call more widely.

“It looked like they were actively trying to attract attention,” she said. Fist tap Dale.

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