Tag Archives: melanin


This gallery contains 3 photos.

For nearly 30 years Leonard and I have observed the red-tailed hawks (Buteo jamaicensis) in Big Valley (Modoc County CA). Not long ago as we were counting red tails along the road, I commented that the number of melanistic red-tailed … Continue reading

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Social Signaling A book I received for Christmas got me interested in melanins in bird feathers. Melanins are pigments found in most organisms. Their chemistry is complex and their functions in many organisms are not understood. In birds they are … Continue reading

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Gloger’s Rule

An ecogeographical rule concerns itself with the variation of traits (mainly morphological) of an organism over geographical gradients. In 1833 Constantin Wilhelm Lambert Gloger (1803 – 1863), a German ornithologist and zoologist, proposed that within a species of warm-blooded animals, … Continue reading

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Blue-headed Mallard

This gallery contains 3 photos.

As one of the most common ducks in North America, most everyone is familiar with the iridescent green head of the male mallard (Anas platyrhynchos). Feather color, as I mentioned in an earlier post, is determined by pigments, the structure … Continue reading

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