i6— DEATH-FEIGNING INSTINCT IN THE OSTRICH. 



By J. E. DuERDEN, Ph.D., A.R.C.S. 



Professor of Zoology, Rhodes University College, Grahamstown. 



Justly or unjustly the ostrich has become proverbial for stupidity. 

 Both in literature and conversation the bird is frequently referred to 

 as representing the extreme of foolishness from its supposed habit 

 of hiding its head when alarmed, and leaving the rest of its body 

 exposed to observation and danger. It must be understood that in 

 applying such terms to an animal's behaviour we are, without 

 warrant, presupposing consciousness and passing the same judgments 

 upon it that we would upon the actions of an intelligent human 

 being. Perhaps an enquiry into the actual habits of the ostrich and 

 their underlying significance may serve to shed some light upon the 

 justification or otherwise for the doubtful mentality usually accorded 

 the bird. One generally discovers there is some foundation of fact in 

 the habits of creatures or persons which have become bywords, 

 though it is often found that in the first and superficial impressions 

 the true significance of the phenomenon has been missed. 



All ostrich breeders are aware that if ostrich chicks, while only 

 a few days or weeks old, are suddenly startled they will at once 

 crouch down, as if dead, and remain thus for some time. The 

 action is much more likely to occur if the chicks have been hatched 

 and reared out on the veld, away from human influence. An actual 

 personal experience will best illustrate what happens. Driving over 

 an ostrich farm one day a pair of ostriches were come upon, sur- 

 rounded by a dozen or so chicks about a week old ; the chicks had 

 been hatched out on the open, and no personal attention given them. 

 Dismounting from the cart, a sudden, clamorous rush was made 

 towards the group, when the parent birds at once ran away and 

 the chicks scattered and disappeared so suddenly and so completely 

 that for the moment one knew not which way to turn in order to 

 follow them. After remaining quiet for a few moments, and getting 

 the eye accustomed to the surroundings, it was found that several 

 chicks were lying quite near, so that one might almost have stepped 

 upon them. Their bodies were prone upon the ground, with the 

 neck and head stretched out resting upon the surface. The re- 

 semblance of the mottled black and brown bodies of the chicks to 

 the rocky ground and scant vegetation was so perfect that it was with 

 much difiiculty the various individuals were discovered. 



The recumbent chicks allowed themselves to be approached and 

 picked up. when thev were foui'd to be quite limp and motionless, 

 appearing altogether lifeless, and only recovered after being conveyed 

 for some distance. 



This behaviour on the part of the ostrich chick is a clear and 

 striking instance of death-feigning or death-shamming. In this state 

 the animal appears and acts as if dead, and, thinking of it in terms of 

 human actions, we explain it as if consciously assumed for the 

 purpose of deceiving its enemies. The same instinct is also well 

 developed in many birds (rails, bustards), mammals (opossum, 

 jackals, foxes), and especially in insects. 



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