As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Friday, 3 May 2019

Why unique finches keep their heads of many colors


An underlying selection mechanism prevents one color from dominating
Date:  April 23, 2019
Source:  Cornell University
There appears to be an underlying selection mechanism at work among Gouldian Finches -- a mechanism that allows this species to produce and maintain individuals with red heads, black heads, and yellow heads. Research by scientists from the the University of Sheffield in the United Kingdom, the Cornell Lab of Ornithology, and other institutions, reveals what this additional evolutionary process might be. Findings were published today in the journal Nature Communications.
"Most people have heard of natural selection," says lead author Kang-Wook Kim at the University of Sheffield. "But 'survival of the fittest' cannot explain the color diversity we see in the Gouldian Finch. We demonstrate that there is another evolutionary process -- balancing selection -- that has maintained the black or red head color over thousands of generations."
The yellow-headed type (actually more orange) is produced by a completely different mechanism that is not yet understood. Yellow-headed Gouldian Finches make up less than one percent of the wild population.

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