92 



ECOLOGY 



Part II 



*^j>.~'V.*«««» jS^ 



Fig. 6.1. The overpopulation of rabbits in Australia, too many for the space and 

 food available, a prime cause of competition and ultimate destruction. This tele- 

 photo lens picture shows how rabbits denude the pastures and drink the water holes 

 dry. (Courtesy, Australian News and Information Bureau, New York.) 



birds, as in seed-eaters and insect-eaters, among larvae of insects, e.g., tomato 

 worms and cabbage worms. The rabbits of Australia, a country almost without 

 predators, have repeatedly overpopulated the land, devastated vegetation, and 

 brought themselves to starvation (Fig. 6.1). 



Cooperation, conscious or unconscious, is the behavior of plants or animals 

 which benefits the lives of those about them. Animals may produce a flourish- 

 ing population beneficial to all concerned. They easily pass this point however, 

 by multiplying to such an extent that they are hungry and sick for want of 

 food and space. Thus their cooperation may be turned to disoperation. Exam- 

 ples of cooperation are plentiful. In winter bees crowd together in clusters 

 within the hive and thus conserve the heat in their bodies. Northern musk oxen 

 stand close together, heads down, against attacking wolves; geese band to- 

 gether with outstretched necks to hiss their disturber. People join in applause 

 by clapping their hands together; tent caterpillars join in making their web 

 and mending it when it is torn; beavers work together on their winter lodge 

 and their food stores (Fig. 6.3). 



Competition and cooperation are fundamental biological principles. Com- 

 petition has long been recognized as such, especially since Darwin based his 

 Theory of Natural Selection upon it. Although the importance of cooperation 

 had been suggested by certain European workers, its prevalence and the 



J 



