Date: Mon, 21 Jul 2003 12:51:39 -0400 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Philip Webre Subject: Off topic: in todays's Washington Post Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Content-Disposition: inline In case you missed this City Birds Hit the High Notes Even birds, it seems, sometimes need to raise their voices to be heard over the din of the city. Hans Slabbekoorn and Margriet Peet of Leiden University in the Netherlands studied the mating songs of a species of bird known as the great titmouse living in different parts of the Dutch city of Leiden. Male birds living in the noisier parts of the city tended to sing higher notes, which other birds can hear more easily above the racket around them, than their counterparts in the quieter parts of the city, the researchers found. Although it is possible that birds choose places to live that match their songs better, the researchers said it was more likely that the birds adjusted the songs to their habitat. "Our findings show, to our knowledge for the first time, that human-altered environments might change the communication signals of a wild bird species," the researchers wrote in the July 17 issue of the journal Nature. Because mating calls are crucial for the survival of a species, those that are unable to make that kind of adjustment may be at greater risk of extinction, the researchers said. "Cars, planes and all sorts of machinery create a new selection pressure on wildlife species that use acoustic signals to achieve reproductive success," they wrote. "This might create two groups of species: one that can adapt their signals to the competing noise, and another that cannot." -- Rob Stein ? 2003 The Washington Post Company ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================