The Variation of Animals and Plants under Domestication · Charles Darwin
THE GUINEA FOWL.
The domesticated Guinea fowl is now believed by some naturalists to be descended from the _Numida ptilorhynca,_ which inhabits very hot, and, in parts, extremely arid districts in Eastern Africa; consequently it has been exposed in this country to extremely different conditions of life. Nevertheless it has hardly varied at all, except in the plumage being either paler or darker-coloured. It is a singular fact that this bird varies more in colour in the West Indies and on the Spanish Main, under a hot though humid climate, than in Europe.[44] The Guinea fowl has become thoroughly feral in Jamaica and in St. Domingo,[45] and has diminished in size; the legs are black, whereas the legs of the aboriginal African bird are said to be grey. This small change is worth notice on account of the often-repeated statement that all feral animals invariably revert in every character to their original type.
Text from Project Gutenberg, public domain in the United States.