'Mamãe' ave sabe melhor , mesmo antes do nascimento, dizem pesquisadores

domingo, março 28, 2010

Mother Birds Know Best -- Even Before Birth

ScienceDaily (Mar. 27, 2010) — Mother birds communicate with their developing chicks before they even hatch by leaving them messages in the egg, new research by a team from the Department of Zoology, University of Cambridge, has found.

New research reveals that mother birds communicate with their developing chicks before they even hatch by leaving them messages in the egg. (Credit: Fernando Trabanco)

By changing conditions within the egg, canary mothers leave a message for their developing chicks about the life they will face after birth. In response, nestlings adjust the development of their begging behaviour.

If chicks get a message that they will be reared by generous parents then they beg more vigorously for food after hatching. But chicks that are destined to be raised by meaner parents end up being much less demanding.

By attending to messages in the egg, nestlings gain weight more rapidly because they match their demands to the parents' supply of food, and can avoid either begging too little or wasting effort on unrewarded begging.

The Cambridge team made the discovery using fostering experiments, exchanging eggs between canaries' nests so that the chicks grew up in an environment that they were not expecting.

"This work changes our understanding of the pre-natal environment in birds," says Dr Rebecca Kilner of the University of Cambridge, who led the research.

"We've known for about twenty years that maternal substances in the egg can influence how chicks develop, but the common assumption is that they are a means by which mothers manipulate their offspring in a way that suits the mother more than the chick.
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Read more here/Leia mais aqui: Science Daily

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Science 12 March 2010:
Vol. 327. no. 5971, pp. 1373 - 1376
DOI: 10.1126/science.1186056

Parent-Offspring Conflict and CoadaptationCamilla A. Hinde, Rufus A. Johnstone, Rebecca M. Kilner

The evolution of family life has traditionally been studied in parallel by behavioral ecologists and quantitative geneticists. The former focus on parent-offspring conflict and whether parents or offspring control provisioning, whereas the latter concentrate on the coadaptation of parental supply and offspring demand. Here we show how prenatal effects on offspring begging can linkthe two different approaches. Using theoretical and experimental analyses, we show that when offspring control provisioning, prenatal effects primarily serve the parent’s interests: Selection on parents drives coadaptation of parent and offspring traits. In contrast, when parents control provisioning, prenatal effects primarily serve the offspring’s interests: Selection on the offspring drives coadaptation of parent and offspring traits. Parent-offspring conflict may thus be responsible for the selective forces that generate parent-offspring coadaptation.

Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.

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