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Updated: June 26, 2025
'Anwendung der Darwin'schen Lehre, Verh. d. n. He found that the males of some species greatly exceeded the females in number; in others the reverse occurred; and in others the two sexes were nearly equal. But as in most cases the males emerge from the cocoons before the females, they are at the commencement of the breeding-season practically in excess.
Birds which habitually fight during the breeding-season are generally ready to fight at all times; and the males of the capercailzie sometimes hold their Balzen or leks at the usual place of assemblage during the autumn. As shewn in a previous chapter, singing is to a certain extent an art, and is much improved by practice.
They are only temporarily developed during the breeding-season; and Dr. Gunther suspects that they are brought into action as prehensile organs by the doubling inwards and downwards of the two sides of the body. It is a remarkable fact that the females and not the males of some species, as of Raia clavata, have their backs studded with large hook-formed spines.
When the sexes differ in more important structures, it is the male which is provided with special sense- organs for discovering the female, with locomotive organs for reaching her, and often with prehensile organs for holding her. These various structures for charming or securing the female are often developed in the male during only part of the year, namely the breeding-season.
It occurs also in Alderney in the autumn, but I have not seen it there in the breeding-season. Professor Ansted includes it in his list, but only marks it as occurring in Guernsey. There are a male and female, in breeding plumage, in the Museum, and also one in winter plumage. OYSTERCATCHER, Haematopus ostralegus, Linnaeus. French, "Hiûtrier pie."
In Europe and in India he leads a solitary life, except during the breeding-season; but as is believed by Sir W. Elliot, who has had many opportunities in India of observing this animal, he consorts at this season with several females. Whether this holds good in Europe is doubtful, but it is supported by some evidence.
A common winter visitant to all the Islands, arriving about the end of October or beginning of November, and remaining till the spring, sometimes till they have nearly assumed the black breast of the breeding-season; but I do not know that the Golden Plover ever breeds in the Islands, at all events in the present day.
George Mivart informs me that it is not furnished with muscles, and therefore cannot be used for locomotion. As during the season of courtship it becomes edged with bright colours, there can hardly be a doubt that it is a masculine ornament. In many species the body presents strongly contrasted, though lurid tints, and these become more vivid during the breeding-season.
When the young resemble the females in their summer dress, or the adults of both sexes in their winter dress, the cases differ from those given under Classes I. and III. only in the characters originally acquired by the males during the breeding-season, having been limited in their transmission to the corresponding season.
From the foregoing facts, more especially from neither sex of certain birds changing colour during either annual moult, or changing so slightly that the change can hardly be of any service to them, and from the females of other species moulting twice yet retaining the same colours throughout the year, we may conclude that the habit of annually moulting twice has not been acquired in order that the male should assume an ornamental character during the breeding-season; but that the double moult, having been originally acquired for some distinct purpose, has subsequently been taken advantage of in certain cases for gaining a nuptial plumage.
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