our jays. This helps to illustrate the great uniformity of life in the broad belt of conifer- 

 ous forest that encircles the northern part of the globe. This similarity is shown in many 

 species of birds: Richardson's owl, the American three-toed woodpecker, the raven, the 

 Canada jay, the kinglets, the black-capped chickadee, and the crossbills of our conifer- 

 ous forests — each finds a closely related counterpart in Eurasia. 



The "mobbing" of an owl depicted here is one example of a very widespread phe- 

 nomenon, the gathering of a number of species of potential prey to scold and pester a 

 potential predator. It may be a group of small songbirds about an owl, a hawk, a 

 snake, or a fox. It sometimes seems to be an expression of curiosity about an animal 

 seldom seen, in which the curious birds, becoming excited, call loudly and attract 

 others. Crows and jays often take a leading part in such assaults on owls. Apparently 

 they do it purely for amusement, and they seem to enjoy the excitement they stir up. 

 Sometimes, especially with snakes, it almost seems as though a peculiar, instinctive 

 type of behavior has evolved as a response when a snake is seen under certain condi- 

 tions. This type of behavior does not seem to correlate well with the distinctly aggres- 

 sive actions of, say, a kingbird driving a hawk or a crow out of its territory, or the 

 frenzied chasing of a cat by a nesting pair of robins, in which a direct aim is in sight 

 and is often achieved. 



The usefulness of the mobbing behavior to an individual bird is doubtful. It would 

 seem safer for the bird to keep its distance. But from the viewpoint of the species or the 

 population it is perhaps beneficial. The predator's location is advertised. It cannot 

 move without its attendant chattering annoyers, so that it cannot surprise its intended 

 prey. Hunting becomes impossible in that area, and from this point of view the birds 

 may be thought to band together for their common benefit. 



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