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in his fascinating book, The Courtship of Animals. He says—[33]

      “The solution of this problem probably lies with the physiologist. We now know that the problem of sex does not rest merely in the complete development of the primary sexual organs; we know that fertile unions do not depend merely on the act of pairing, but on the functional activity of the ancillary glands. And it may well be that some change in the character of the secretions has not only affected the numerical values of the sexes, but reversed the normal rôle of coloration and behaviour.”

      Mr. Pycraft does not consider that the polyandrous habits of these birds are due primarily to a preponderance of the females in the species over the males, but holds that this condition must rather be regarded as having arisen from a transference to the females, or development in them, of increased sexual hunger, which intensity of passion would tend to lead to an exhaustion of the males. This is exceedingly interesting. Mr. Pycraft continues—

      “Neither polygamy nor polyandry among the lower animals, at any rate, has been brought about or is maintained by the excessive death rate due to combats for the possession of mates, but must be explained as demonstrating inherent changes in the germ-plasm, disturbing the relative proportions of the sexes and correlated with a profound transformation, not only in the behaviour of the sexes during the period of reproductive activity, but also in their physical characteristics.”

      If I understand this aright, the conclusion seems forced upon us that parental conduct is directly dependent on the action of the sexual appetite: that it may be modified, and in some cases profoundly changed, by any variation in this appetite’s strength and expression. This is of profound interest, and such a view, if established, might explain a great deal.[34] But can it be accepted? To say that such changes are due to the action of the “hormones,” or secretions of the sexual glands, does not help us very much. What we want to know is what induces the changes. There is much that cannot yet be explained. If I may venture to speculate on so difficult a question, it would seem that when the intensity of sex-hunger becomes for any reason stronger in the females than in the males, the result may be a diminishing of the instincts of motherhood. It is as if the egotistic desires of sex were in opposition to the racial duties. This would explain the female phalaropes, whose maternal instincts are completely atrophied. Does it not suggest also a possible explanation of some failures in human motherhood? This opens up questions that reach very far. I am tempted to wait to enlarge on the immense significance of these unnatural bird-mothers in the analogy their conduct bears to one of the most difficult cases of human motherhood—the strongly sexual woman who bears children but is quite unfit and without any desire to rear them. I shall have more to say in the later part of my inquiry about such women, who are driven by passion to be mothers without having any instinct for motherhood.

      But now a return must be made to the birds’ nurseries. It is a matter of common knowledge that birds display a marvellous solicitude for the welfare of the young, and their family life presents a beautiful and high standard of conduct.[35] There are very few examples of birds who are bad fathers. Often the male rivals the female in love for the young; he is in constant attendance in the vicinity of the nest; he guards, feeds, and sings to the female, and often shares with her the duty of incubation. The cock ostrich, for example, watches by night over the hole in which the eggs have been buried, and the hen takes this duty by day. The screamer birds, again, work in shifts of two or three hours each. When they bred in the London Zoological Gardens, it was noticed that the cock-bird acted as timekeeper, and at the end of a watch used to come and push the female off the nest.[36] These examples are delightful. It would seem almost that the males, when infected with paternal passion, were more ardent and regular in the performance of nursery duties than the mother.

      Among many birds it is usual for all family work to be performed quite irrespective of sex, and the parent who is free takes the task of feeding the one who is occupied with the nest.[37] The male hornbill is a family despot; during the breeding season he walls up his spouse within the trunk of a tree. He feeds her with great care, but he allows her no liberty. As soon as one family is reared many birds at once burden themselves with another. The Californian quail affords an example. In this species the father takes sole charge of the family as soon as the young birds attain the age of three weeks, when the mother begins the labours of rearing a second brood. More curious are the habits of the water hen, among whom the young of the first family assist in the work of feeding their brothers and sisters of the later broods.[38]

      The labour of feeding the young family is a heavy task in which both parents commonly share. There are no cases of unsuitable feeding of nestlings by careless or ignorant parents. A regular course of nursery dietary is practised, in particular with nidicolous species, where the young are born in a helpless condition; often a special infant food is prepared by a process of regurgitation, or food partly digested and thrown up. Thus baby finches are fed on food made of digested insects; parent parrots also prepare a digested vegetable food; storks break up worms and frogs and pieces of little fishes and mix it with partly digested matter and throw it out on the edge of the nest for the family meals. Young pigeons thrust their beaks into the mouths of their mothers to absorb the so-called pigeon’s-milk, which is really digested food mixed with a secretion from the crop; little cormorants thrust their bills right down the neck of their mother and help themselves to food out of her stomach. The petrels secrete oil from the fish they eat to feed the young: this oil is used also as a weapon of defence both by the parents and the nestlings, who squirt it out from their mouths and nostrils at any unwelcome intruder on the privacy of the nest.[39]

      When the young are fed entirely on insects the work entailed on the parents is enormous. A pair of blue tit-mice, for example, have been seen to make no less than four hundred and seventy-five journeys to the nest during a day’s foraging extending over seventeen hours. Again, the male of the common dabchick works untiringly, and has been seen to take as many as forty journeys, with food, in the space of an hour, back to the nest, where his wife waits with the children, which commonly perch on her back and are protected by her wings. Small wonder is there that the labours of both parents are needed to keep the young families from starvation. In some cases a practical division of work is arranged; and the father will bring a different kind of food from the mother. With the stow-chat, for instance, the mother brings small prey, generally spiders, but sometimes butterflies and moths, while the father selects and carries large caterpillars. Even where the young are precocious, fairly active at birth, and soon able to feed themselves, one or both parents for a considerable time guard, teach and protect them. Great bravery and intelligence are displayed in the face of any danger, not only will many parent-birds savagely attack an enemy, but in some cases, as, for instance, the plover or the partridge, the mother will feign to have a broken limb or to be lame, to draw off from the young the attention of the intruder. No parental duty is neglected. Daily lessons are frequently given to the nurslings on the right kind of food and the best way of feeding. Thus young birds of prey are instructed, first in the art of breaking up their food, and later in the best methods of its capture. Young swallows, again, receive a carefully graduated course of lessons on the difficult work of catching the insects which form their food, while they are flying. The parents of the woodcock carry their children to the feeding ground, to and from the nest, supporting the precious little ones with their beaks, and pressed close within their feet, which are used as maternal arms.[40]

      A delightful incident was witnessed during the feeding-time of a red-backed shrike—[41]

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