Birds go by what they hear, not what they see

June 19th, 2008 - 1:32 pm ICT by IANS  

Washington, June 19 (IANS) Birdsongs are not just soothing, they are vital for decision-making in birds, says a new study that contends that our feathered friends are guided more by what they hear than what they see. For instance, researchers found that the chirps of the young are what helped migratory birds decide where to nest themselves.

The warbling indicated that nest-bound birds were successfully parenting babies - a trait so overpowering that researchers playing recorded songs induced migratory species to nest even in “lousy bird habitats”.

The findings of the study significantly imply that what birds hear may be more important than what they actually see or experience.

“Finding the right habitat in which to breed is a matter of life and death for most birds,” said Matthew Betts of Oregon State University, who led the study.

“They don’t live a long time and they need to get it right the first time.”

Common wisdom has it that birds select sites solely on the basis of the vegetation. The logic being that if the nest does not have appropriate cover and food supply, the birds most likely won’t be able to successfully breed.

“But now we know that young birds can listen to the songs of more experienced and successful birds and use this to help decide where they will nest the next year.”

The scientists discovered this in experimental studies at 54 research sites with the black-throated blue warbler in the White Mountains of New Hampshire.

During autumn when some of these birds had successfully mated and were singing to their young - probably to teach the young ones how to sing - the researchers played recordings of their song in other places the birds were otherwise bound to avoid.

Other black-throated blue warblers flying overhead heard these songs and decided it must be a good place to live, all visual evidence to the contrary, and returned to these exact sites the next spring to nest.

“We had a lot of birds come to settle in inappropriate habitat, just because they had heard our recorded bird songs there the previous year,” Betts said. “We were actually pretty surprised that the effect of this communication was so strong.”

The findings of the study have been published in the latest issue of the Proceedings of the Royal Society B.

Tags: , , , , , , , , , , , , , , , , , , ,

Posted in World |