DRAMATIC ART IN NATURE

Evening Star, Issue 19546, 3 May 1927, Page 8

DRAMATIC ART IN NATURE

DECEITFUL BIRDS How the dramatic art has been developed in Nature is a problem, still unsolved, of the biological psychologist. There is no “ let’s pretend ” about it, but intentional and often useful bluff. Indeed, the pretence would not have been developed had it brought no advantage to the majority of pretenders. The bluff may be active or passive, behaviour calculated to deceive or resemblance to some other animate or inanimate object which, though useful, may bo purely fortuitous. The apparently intentional deceit is of most interest to the psychologist. _ The scene was half-drained fields, ditch-bounded Dutch polder, the actors conspicuous black-and-white birds —avocets. White and black is the better description of the costume, for the predominance of white had advantage m the dissimulation of the actors. They protended to be wounded, crippled, in sore distress; the explanation of the sham was that powerful if transient stimulus parental affection. Across this polder runs a straight track, au occupation road, not a thoroughfare; on either side is a deep and wide ditch, with bridges and gates for the use of cattle. As w© walked along this road, watching the wise-looking oyster-catchers standing thoughtful, almost judicial, their long bills reminding ns of vermilion noses, and listening to the cheery music of the natterjacks in the ditch, wo noticed a couple of avocets alongside some shallow pools. They were not feeding? find stood some ten yards apart; they were pretending that we did not interest them. Experience with many other birds caused us to seek explanation of this seeming indifference, and our field glasses revealed two grey-downed _ infants paddling on the mud and feeding. Still trie parent avocets appeared to pay no attention: w© were on a road along which other human beings passed without causing inconvenience, hut immediately w© crossed to their polder they were all attention The long, pointed wings were spread, and after a few running steps the birds rose and flew towards us, calling repeatcclly li Khi©©t, klueefc.” Suddenly one dropned, running with upraised wugs; then, still running, but in a half-crouching attitude, the bird lowered its head, bending the neck so as to keep the slender “ cobbler’s awl bill above the grass, hunched its shouldors, spread and depressed its tad, and allowed the black tips of th© stronglybowed wings to trail on either side. Every few minutes the bird shivered violently, the scapulars and feathers of the back erected, and all the time it moaned, as if distressed. The object was to draw onr attention from the young by extravagant behaviour, and lure us from the danger zone. When we refused to be bluffed the birds made other pretence, stooping at ns with dropped legs and slender bill like lance at rest, but this, too, was sham, for the upturned bill is useless as a weapon of defence. The avocet. is not the only species that endeavors to draw the attention of a possible enemy by a ruse of this nature, or by simulated disablement; indeed, it is a common habit of many ground-resting species, but almost every one has some peculiarity of attitude or behaviour. The ringed plover scrambles along the beach, piping as if in pain, and, falling on one side, feebly waves an apparently injured wing. Th® reed bunting tumbles out of its nest in the marsh and flutters helplessly through the undergrowth. The golden plover is a master performer, and once I saw ono die (writes a 1 Manchester ■ Guardian ’ correspondent). Struggling lamely to a mosshag, it allowed its head to drop over the* edge, as it fell, apparently dead or in a faint, with wings extended. I watched, but did not, approach, and presently the limp head was raised, the bird gave a forlorn squeal, and again collapsed; as this did not draw me, it came to life, ran, piping, towards me, and again began the damaged wing action. . Are these birds pretending that they are injured, and thus are easy victims for a predacious foe ? That is the impression they give, yet we dare not say that they consciously pretend. They ■act, but the dramatic performance is the result of certain stimuli —anxiety rather than fear, instinctive courage due to parentage, and the necessity for protecting young which cannot protect themselves. Ornithologists who study problems ot sexual selection emphasise that in “ display ” or courtship actions the bird makes the most of any prominent mark or color to attract the eye of the opposite sex. A similar exhibition of noticeable characters is, it appears to me, the object of bluffing birds. The habit of pretending to die is shared by very different animals. Some moths and beetles fall inert with limbs drawn in when touched, many snakes and other reptiles will sham, and dogfish, even when on a Look, will stiffen their bodies and remain as if dead; the expression “playing ’possum has its origin in the habit of death-feigmng of certain American marsupials. Although it is true that nervous shock may produce in some birds a temporary comatose condition, and it has been suggested that this is the true explanation of all these apparent deathlike conditions, in most cases they are undoubtedly feints and not faints. In the birds mentioned above the death feigning is part of an active performance calculated to deceive; the simulated disablement, agonised cries,_ apparent abject fear, suggest histrionic ability, pure bluff. . Immediately the cause is removed the bird begins to feed, sleeps, or attends to domestic duties as if nothing had disturbed it. When the actor has led the intruder from the danger zone it will rise with a cry which certainly sounds exultant, even ironical. That, no doubt, is due to the fact that in our interpretation of animal behaviour we cannot keep quite clear of anthropomorphic bias.