parenthood among birds
with further examples of good fathers
“prais’d be the fathomless universe,
for life and joy, and for objects and knowledge curious.”
walt whitman.
two things i have been anxious to bring out prominently in the foregoing chapters: that parental behaviour among the insects, reptiles and fishes presents us with a bewildering diversity of aspects—in particular, that the instinct of caring for the young is not fixed in the mother, but may be transferred from her to the father; and further, that all parental sacrifice, though often unconsciously expended to maintain the well-being of the family, is of direct benefit to the parent who bestows it, and is the surest means of developing and brightening such a parent’s individual intelligence.
now, i wish to elaborate and establish these two propositions with further examples in order that they may be laid hold of and firmly grasped as indubitable facts; and then we may come to see and understand the significance to ourselves of these unusually devoted fathers, which are found, and that not infrequently, among all classes of pre-human parents.
the varied behaviour of bird-parents—more especially of the males—furnishes just the kind of evidence we need. there are several cases known, and i believe there must[100] be others as yet unrecorded, wherein the conduct and, indeed, the whole character of the two sexes is reversed. here the females, driven it would seem by a fierce sex-hunger, do the courting and fight one another as rivals for the males, while the males undertake all the family duties of incubation and brooding and the feeding of the young.
the phalaropes, both the grey and the red-necked species, which are found in scotland and ireland, afford a striking example of these unsexed females. among these birds the r?le of the sexes is reversed. the duties of incubation and rearing the young are conducted entirely by the male, and in correlation with this habit, the female does all the courting. she is stronger and more pugnacious than the male, and is also brighter in plumage. this is really very remarkable. what has acted in bringing about this reversal in the secondary sexual characters? can the male nature be transferred to the female? these are difficult questions. in colour the phalaropes are a pale olive very thickly spotted and streaked with black. the male is the psychical mother, the female takes no notice of the nest after laying the eggs. frequently at the beginning of the breeding season she is accompanied by more than one male, so that it is evident polyandry is practised.[30]
the same unusual family conditions prevail with the rhea and the emu, and also among the painted snipes, cassowaries, tinamous, and some of the button-quails.[31] there are probably instances of other birds, but i do not know of details of their habits; wallace[32] also mentions several[101] species in different parts of the world, among whom all care of the young falls entirely upon the father. in all these bird families exactly opposite conditions prevail to what we are accustomed. it should be specially noted that these unnatural (i use the word simply to mean unusual) mothers are larger and more vividly coloured than the hard-worked fathers; in all such cases polyandry is practised.
why is this?
the only attempt at an explanation that i have been able to discover is given by mr. pycraft 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 r?le 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[102] 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[103] 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[104] 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,[105] 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[106] 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]
“the male had brought to the nest a young bird, and, pulling off its head, proceeded to ram it down the throat of a very unfortunate youngster. but the morsel was too big, and had to be readjusted, not once, but many times; and finally it was forced home with such success that the wretched bird was in imminent danger from choking. at this the female, who had been sitting on the opposite side of the nest, making, apparently, very sarcastic comments on the awkwardness of her lord, and males in general, suddenly seized the offending head and, dragging it forth, proceeded to tear it into small pieces, giving each of the brood a piece. and during this time the male looked on in what appeared to be a very subdued fashion.”
almost all birds take great trouble to ensure the sanitation of the nursery, and are diligent in their care of the health of the young. all the excrements are removed from the nest, a task that is rendered easy, as the droppings of the young are enclosed in a white, film-like envelope or capsule. a most careful search is made at the bottom of the nest for these capsules by the parents whenever they come to feed the young. do they fail to find the expected capsules,[107] one or other of the parents after the feeding will tap, tap on the anus of the young birds as if to remind them of a duty neglected.[42] this is, perhaps, the most extraordinary example of parental care that i have been able to discover. one wonders how far this apparent recognition of the necessity of regular habits and cleanliness is instinctive, or how far we may grant to these parents some direct realisation of the dangers arising to their children from neglect and a dirty nursery.
it must not, however, be thought that all birds are good parents. in some species there would seem to have been a revolt against family ties and the duty of caring for the young. the common cuckoo and some other cuckoos are well-known examples. among them, the mother, as every one knows, always lays the eggs in the nest of some other birds, and the young cuckoo, when it is hatched, would seem to have some knowledge of its precarious position as a stranger. it creeps under the nestlings of its foster-parents, and, by a violent effort, raises them one by one on its hollow back and jerks them out of the nest, so securing undivided attention in its alien nursery. a similar parasitic habit, not yet so firmly established, is found among the cow-birds of the argentine. mr. w. h. hudson has seen the mothers trying to build nests and failing to do this, as if they were struggling to regain a dying instinct. the females flutter about the mud-nests of the oven-birds, and whenever a chance presents itself will dart in and lay their eggs. other cow-birds make no effort at all in nest-building, and always lay their eggs in the occupied nests of other birds, and, as their eggs develop very[108] quickly, the intruders hatch out before the true children of the nursery and rob them of their parents’ care.
what do we learn from this? that neglect on the part of the mother—any shuffling out of her duties, thereby placing the care of her children on the shoulders of other parents, leads to crime and disorder in the social organisation.
some birds are content with very little care for home-building ready for their eggs. birds belonging to many different species make nurseries in hollow trees, caves, burrows or natural cavities, sometimes lining them with leaves and feathers to make them soft, but sometimes even neglecting this care. the new zealand kakapo or ground parrot, to take one instance, hides in any hole it finds and lays its eggs there without any preparation; the kingfisher, again, digs out a hole in the ground, or occupies one that it finds. emus scrape a shallow hole in the ground and do not cover the eggs. the cassowary scrapes together a rude pile of leaves and mould on which she lays the eggs. some of the megapodes or bush turkeys bury their eggs in the sand, and then take no further trouble about them, leaving incubation to the chance warmth of the sun. others build enormous heaps of decaying leaves, forming a hot-bed from natural fermentation, by which the chicks are hatched out with no trouble to the parents. the young of the megapodes are the only living birds that are hatched out able to fly at once and ready to take care of themselves. it would appear that neglectful parents foster self-development in the children.[43]
where the mother broods alone over the eggs it sometimes happens that the father-bird takes no interest in the[109] family. the polygamous gallinaceous birds appear to be without, or to have lost, the paternal instinct. peacocks, pheasants, turkey-cocks, and barn-door cocks do practically nothing for their families, and while the mother-birds’ care in feeding and guarding the young is untiring, the fathers are running after amorous adventures. the conduct of the male turkey is even worse, for, prompted by jealousy, he will often attempt to devour the eggs, and the young are protected from his attacks only by the mothers uniting together in troops. here we see the exact opposite conduct in the two sexes from that in such a family as the sticklebacks, where good fathers replace bad mothers. but the same result follows. in either case the neglect of parental duty by one or other parent is a source of weakness to the family and increases the risks to which the young are exposed.[44]
i must insist on how strongly conduct is affected by the conditions of the home; and any change of habits will directly modify parental behaviour. thus an animal habitually domestic may easily change under the pressure of external causes. thus wild ducks, though good parents and strictly monogamous, and very highly developed in social qualities when in the wild state, become indifferent to their offspring and loosely polygamous under domestication.[45] civilisation, in this case, depraves the birds as often it does men. but the examples of bad parents among birds are few in number.
i will end this chapter by relating, with as much detail[110] as is possible, the curious family history of the adélie penguins;[46] as these birds have developed some interesting and startling experiments in nursery care and parenthood. the penguins live in large social colonies. it should be noted first that the death rate among the young birds is enormously high, as happens invariably where the single family is replaced by great breeding colonies.
yet the penguins are self-sacrificing parents. year by year in the month of october they return to the same breeding-ground, having travelled many hundreds of difficult miles, and urged by a mysterious nostalgia that their children may be born in the same home. the first duty is to take possession of one of the old stone nests, or to scoop out a new hollow in the ground. here the hens sit by the future home, and wait for proposals from the cocks. the advance is made by what appears to be a symbolic action and the cock places a stone at the hen’s feet. but often the hen answers never a word. bloody duels are fought between rival suitors to arouse her passion and prove the vigour of her mate.
both birds work at the home-making, repairing an old nest or forming a new one, which is made of rounded stones. the cock collects these, and it is interesting to note what would seem to be an ?sthetic taste in these bird-builders; certain painted pebbles, provided by the explorers for the use of the birds, were in great demand, the colour red being preferred to green.
[111]
during the first days of wedded life the conflicts between the cocks continue, and the chosen cock maintains his rights by driving off all interlopers; but later, when the pair settle down to the serious duties of the family, they live in peace and are perfectly faithful to each other. not until the eggs have been laid does either parent go to feed; the shortest period of total abstinence from food being about eighteen days and the longest about twenty-eight days—a fine example of parental sacrifice. then one of the birds marches off to the water for a holiday, which may last from seven to ten days, after which it comes back to give the other bird its turn. when the young penguins are hatched the parents share in the work of feeding and guarding them, and relieve each other at frequent intervals. the bird who goes to feed always returns heavily burdened with provisions, and its always quaint shape becomes grotesque, when so laden with crustaceans that it has to lean backwards to keep its balance. sometimes a bird will try to carry too much, with the result that it tumbles over and loses the entire load. the young chicks feed in the same way as the young cormorants, by thrusting their heads into the parent’s gullet.
though both birds work together and with the same zeal, it must be noted that the mother’s guard over the young is more strict than is that of the father. when the mother is sitting, nothing, not even a wrangle with her next-door neighbour, will induce her to move from her post. whatever happens, there she stays until her turn for relaxation comes. but the cocks are more easily led astray. their combativeness causes them to forget family affairs. often much harm is done by these quarrels in the crowded rookery, which occur frequently and in spite of the protests[112] of anxious neighbouring parents, who are seen trying to make peace.
the most curious habit of these delightful birds has still to be recorded. they have developed a taste for games, such as leaping, diving and boarding the ice-floes. these amusements are indulged in by the adults, who band themselves in large companies, and play occupies much of their time. to gain the necessary freedom for this fun from their homes, and without leaving the chicks to perish, a most instructive device has been evolved by the penguin parents. the birds with young families “pool their offspring” in groups, which are left in charge of a few conscientious birds, both cocks and hens, who act as nurses; they ward off the attacks of the sukas, and keep, or try to keep, the chicks from wandering. the holidaying parents bring food at intervals—when their consciences smite them—and they remain faithful to their own crêches.
this is, i think, the earliest example of what must be regarded as a premeditated experiment in co-operative child-rearing. for the parents it doubtless has many advantages. these remarkable birds certainly appear to find a quite unusual joy in life: we read of the ecstatic attitudes they will frequently assume and the weird “chant de satisfaction” which they utter during play when all is well with their world. yet the fact, already noted, must not be overlooked that the death rate in the rookery is enormously high; indeed, a frightful mortality often overtakes the young chicks when left by their parents. the children pay for the escape on the part of the parents from the sacrifice parenthood must entail.
i have a further case to record of a different experiment in co-operative parenthood, in this case necessitated[113] through the severities of the struggle of life. in the same antarctic regions where the adélie penguins make their home there dwells another penguin, the great emperor penguin. this bird has a sad history; never, during the whole course of its life, does it touch dry land; the vast ice-fields form its only home, and it has to brave the perils of the open water in its search for food. under such circumstances the struggle for life is severe, and the parent-birds have the greatest difficulty to rear the young. in these ice-nurseries, incubation in the usual manner in a nest is impossible; a new and curious method is adopted. each mother lays but a single egg, which is placed for warmth and safety in a “brood-spot” situated at the back of the feet, where it is covered by the overlapping feathers of the abdomen. even this care is not rewarded always, and many of the eggs perish.
owing to the difficult incubation, a large percentage of brooding birds are left without eggs and young. and the curious thing is that this loss seems to increase the desire for offspring, until the parental instinct becomes a tormenting passion. this is what happens. each childless bird strives to adopt a child from the more fortunate parents; and this leads to a competition in parenthood, which of its kind is without parallel.
not only the duty of incubation, but afterwards caring for the young chicks, is carried out not by one bird only, but by a dozen or more, which stand patiently round for a chance to seize either a chicken or an egg. nor is it, as might be expected, the mothers alone who are seized by the passion of thwarted maternity; the fathers help their childless wives in their efforts to steal offspring. every bird, male as well as female, has developed the “brood-spot,” and[114] has the same bare patch of skin at the lower part of the abdomen against which the egg, when possessed, is pressed for warmth.
“what we actually saw, again and again,” states dr. wilson, “was the wild dash made by a dozen adults, each weighing anything up to ninety pounds, to take possession of any chicken that happened to find itself deserted on the ice. it can be compared to nothing better than a football scrimmage, in which the first bird to seize the chicken is hustled and worried on all sides by the others while it rapidly tries to push the infant between its legs with the help of its pointed beak, shrugging up the loose skin of the abdomen the while to cover it.… the chicks are fully alive to the inconvenience of being fought for by so many clumsy nurses, and i have seen them not only make the best use of their legs in avoiding so much attention, but remain to starve and freeze in preference to being nursed. undoubtedly, i think that of the 77 per cent. that die before they shed their down, quite half are killed by kindness.”
it is from such an example as this that we may come to realise the extraordinary power of parent-hunger. consider these penguin mothers and fathers clamouring and fighting for the possession of a child. with them the parental instinct has gained fierce strength from being thwarted. is there not here yet another lesson for us to learn?
