MORE ABOUT ANIMAL BEHAVIOR ! 
By Ernest P. WALKER 
Assistant Director, National Zoological Park 
[With 16 plates] 
INTRODUCTION 
The scope of the subject ‘‘animal behavior’ is almost unlimited, for 
every species has its own particular pattern of behavior and the indi- 
viduals of the species show many variations even from that pattern, so 
that the subject could really be made an exhaustive study for each 
and every species. Although psychologists have made extensive 
studies of human behavior, actually they have merely made a good 
beginning. Glimpses of animal behavior and some conception of how 
behavior patterns may have developed frequently help in explaining 
human behavior and human reactions, for our reactions are the result 
of a long series of experiences of trial and error and elimination by 
natural causes just as has been the case with those of other animals. 
Similar causes have brought about similar reactions in many 
instances, and different causes and environment have developed 
different reactions; there is, therefore, a remarkable diversity of 
behavior pattern among the different kinds of animals that live under 
many different conditions. Those that have not been able to adjust 
themselves to their environment have become extinct and are usually 
known only by their fossil remains; those that could adapt themselves 
and multiply are the forms that have survived to the present day. 
The activities in an animal’s life are essentially the same as the basic 
activities of humans. Individuals must survive, and to do so they 
must be able to avoid enemies, to obtain food and shelter; and for the 
species to survive, the individuals must reproduce and the young must 
be given an opportunity to start their own struggles for survival. 
No doubt everyone who has observed animals closely has seen them 
do many things that could not be explained in the light of our ex- 
periences and practices. However, we must judge and interpret the 
1 An earlier article by the same author, under the title ‘‘Animal] Behavior,’ appeared in the Annual 
Report of the Smithsonian Institution for 1940, pp. 271-312, 18 pls. As the first paper has been out of print 
for several years, some of the same ideas and examples contained in it are incorporated in the present paper, 
although not as exact quotations. 
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