T H E STUDY OF heterochtosis or colour variations in the plumage of birds is a subject that the majority of field ornithologists either ignore entirely or regard with only mild curiosity. In the early years of the present century and before that, however, interest was more widespread and a number of very fine skin collections of abnormally coloured birds were built up. Among the most notable were ...

Stay at the forefront of British birding by taking out a subscription to British Birds.

Subscribe Now