Hi Everyone, If what Martin says is correct, it would mean that producing higher frequencies in a bird that is deaf for those frequencies would not require increased energy intake, i.e., food. Otherwise natural selection could have favoured those individuals who did not produce those higher frequencies, regardless of whether males hear them or not. Unless of course females are able to hear these frequencies and can use them as a proxy for prowess in males with regard to territory acquisition and maintenance. Are there any studies on the ability of female birds to hear higher frequencies in the respective species?
Harald on 3/28/08 6:37 AM, Martin Braun at [EMAIL PROTECTED] wrote: > Michael Stocker wrote: > > "We could infer that they do use these sounds for something which > involves their being able to hear them ...." > > This may not always be true. Imagine the following scenario: > > A bird is deaf above 6 kHz. If this bird has sound components > around 10-12 kHz in its calls, it cannot hear these components and it is > thus unable to influence its voice organs to reduce or even eliminate > them. > > Martin > > --------------------------------------------------------------------- > Martin Braun > Neuroscience of Music > S-671 95 Klässbol > Sweden > web site: http://w1.570.telia.com/~u57011259/index.htm > > > > ----- Original Message ----- > From: "Michael Stocker" <[EMAIL PROTECTED]> > To: "'Martin Braun'" <[EMAIL PROTECTED]>; <[email protected]> > Sent: Wednesday, March 26, 2008 4:55 PM > Subject: RE: Songbird audiograms > > > Perhaps not, but it would be biologically expensive to have all of that > energy dedicated to high frequency vocalizations and not be able to hear it. > We could infer that they do use these sounds for something which involves > their being able to hear them - but at the moment it may not be indisputably > proven. > > Michael Stocker > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Martin Braun > Sent: Tuesday, March 25, 2008 12:14 PM > To: [email protected] > Subject: Re: Songbird audiograms > > Dear friends, > > it is not possible to infer from the sound spectrum of the calls of a > species anything about the hearing range of this species. > > Martin > ************************************************************************** Harald Yurk, Ph.D. Research Associate Cetacean Research Laboratory Vancouver Aquarium Marine Science Centre PO Box 3232 Vancouver, BC, Canada V6B 3X8
