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re. another difficult question

To: Lyndy or Graeme <>,
Subject: re. another difficult question
From: John Gamblin <>
Date: Wed, 25 Feb 2004 17:02:44 +1100 (EST)
G'day Graeme,
 
If you go with the thought that many birds build nests in the shade which is where the young are raised then those born with black and white colouring should stand a better chance of survival from predation?

Lyndy or Graeme <> wrote:
 
We must think convergence and then functional values. What habitat qualities may be the same for all locations which will select for black and white, long tail, jerky motion?
 
What functional values do these characters give? Off the top of my head, water enables riparian vegetation which leads to shade and light mottling. Maybe black and white is good camoflage for this light condition. Riparian veg. and water leads to insects. Jerky motion may simply be good for locating and catching small insects. Long tail may be a suitable morphology for rapid direction change, jerky motion. Or something completely different.
Graeme
 
Willie Wagtails?
 
JAG tail whagging



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