another difficult question black and white colouring

["Philip A. Veerman" <>]

How about that black and white colouring may be the cheapest way (i.e. not needing complex pigment patterns, just melanin or not) for a bird to make itself very obvious for the benefit of social signalling or for Muellarian mimicry as many insect show (cf. Batesian mimicry). Most black and white birds are by their behaviour very conspicuous, so it is clearly not a camouflage. Camouflage only works when the behaviour supports it.

 

Philip

-----Original Message-----
From: John Gamblin <>
To: Lyndy or Graeme <>; m("vicnet.net.au","birding-aus");"> <m("vicnet.net.au","birding-aus");">>
Date: Wednesday, 25 February 2004 17:04
Subject: Re: [BIRDING-AUS] re. another difficult question

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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