WHAT IS THE MEANING OF PREDATION? ^ 



By Paul L. Eebington 



The writings of antiquity contain references to the depredations 

 of wolves, lions, and other predators upon flocks, and even to the at- 

 tacks of predators uj)on man himself. But though the preying of 

 one animal upon another has long attracted man's attention, man 

 has made comparatively little effort really to understand such a 

 conspicuous and universal phenomenon. The idea rarely occurs to 

 anyone that there is a great deal to understand, the thought rather 

 being that the predator kills and eats the prey, and that is all there is 

 to it. 



From this elementary concept of predation, a number of apparently 

 logical conclusions usually are drawn. For example, if one predator 

 kills so many anmials of the kinds that are being preyed upon, more 

 predators kill that many more; hence, more predators mean fewer 

 prey animals. Conversely, if there were fewer predators, there would 

 be more prey animals and so on. However, things do not always 

 work out so simply in nature. 



The widespread misconception of the effectiveness of predation in 

 determining animal population levels is responsible for much reason- 

 ing that goes astray. Predation has been shown by recent studies 

 not to be, in a collective sense, an inexorable tax upon the luckless 

 prey species, to be satisfied in full. 



Life to wild animals unquestionably is often harsh, but the de- 

 mands of predators in temperate regions are not apt to be so drastic 

 as to make existence a neck and neck race between the great appetite 

 of predation and the breeding rates of the prey animals. 



McAtee, for one, concludes that very few animal populations ap- 

 proach the limits of their food supply in nature,^ and predator popu- 

 lations are not any general exception. Predators may occasionally 

 starve, and predator pressure may at times be about all that a prey 

 species can stand, or conceivably more than it can stand; but, for all 



^ Journal Paper No. J374 of the Iowa Agricultural Experiment Station, Ames, Iowa. 

 Project No. 330. 



■McAtee, W. L., The Malthusian principle in nature. Scientific Monthly, vol. 42, pp. 

 444-456, 1936. 



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