Female Birds Boost Up Their Eggs When Hearing Sexy Song

We've been told that a way to a man's heart is through his stomach. Could the way to a woman's be through her ears?

Thanks to Kentaurian for the article from PhysOrg.com.

Female Birds Boost Up Their Eggs When Hearing Sexy Song

In a new study published in the latest issue of Ethology researchers show
that female songbirds can alter the size of eggs and possibly the sex
of their chicks according to how they perceive their mate's quality. The researchers played back attractive ("sexy") songs and less attractive control songs of male canaries to female domesticated canaries.

When the females started egg-laying they varied the size of their eggs
in the nest according to the attractiveness of the male's song. That is, the
more attractive the song, the larger the eggs.

However it is remarkable that while larger eggs were more likely to
contain male offspring in natural environments, in the experiment there was no
difference in brood sex ratio between the different songs played to the
females, which suggests different levels of female control.

Male birdsong has long been known to attract females and influence mate
choice decisions and even induce an alteration in the offspring's sex
ratio.

This study by Leitner et al. now shows experimentally that hearing
attractive song also has a selective impact on female physiology.

45 female domesticated canaries participated in this study that was a
collaboration of Royal Holloway, University of London and the Max
Planck Institute for Ornithology in Seewiesen and Radolfzell in Germany.

The birds were kept in large aviaries where their daily behaviour was
monitored in a colony before they were tested in the song experiments.
The females showed a remarkable consistency in their behavioural and reproductive
performance and the song stimuli alone were sufficient to elicit a
profound physiological change.

This study further highlights the importance of behavioural stimuli
for reproductive physiology...

Copyright 2006 by Space Daily, Distributed United Press International
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Of course we know from Pale Male's example that the way to get certain things you want is...PRESENTS! D.B.