6 



Mutual Relations nips or Animals 



Whirligig beetles spin and turn in companies on the pond surface; a hundred 

 starlings swing into a treetop; swarms of gnats rise and fall in quiet air; men 

 and women join in a folk dance. These are all social beings, those of each 

 group sharing particular surroundings. Animals express their sociability by 

 being in the same place at the same time. 



Two kinds of behavior, competition and natural cooperation, are character- 

 istic of sociability. 



Competition and Cooperation 



Competition occurs when there is a common demand on a limited supply. 

 A certain amount of it is stimulating and healthy. An unlimited competition 

 is dangerous to individuals and communities. Its basic cause is the overpro- 

 duction of animals, human or otherwise. During the spring breeding season 

 many small ponds are populated with toads and each female lays about 15,000 

 eggs in a clutch. Presently the water swarms with toad tadpoles. All these tad- 

 poles have insistent appetites for the algae of the green pond scum that over- 

 spreads the water. At the start there is an abundance of algae as well as tad- 

 poles but it thins out as the eating goes on. Then competition begins. Some of 

 the tadpoles manage to get food, but many of them starve. If they were fighting 

 animals, there would be conflicts along with the starvation. In all communities 

 plants and animals compete for such essentials as earth, water, food, warmth, 

 and light as well as for less necessary things. Competition is commonly accom- 

 panied by a struggle for power and dominance usually gained by one or a few 

 individuals. 



Competition is usually keenest between those of the same species since they 

 have the same wants; two rabbits go for clover, but a sheep eats grass and a 

 cat eats birds. The overpopulation, sparsity of food, and starvation of individ- 

 uals that occur in nonhuman animals have been matched in human ones 

 throughout history. Competition is reduced by differences of diet: among 



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