Teeters, Nods, and Bobs 193 



I have seen it busily examining the small expanse of open 

 water in a mountain lake after the cold November nights had 

 frozen all but that one small area. The bird dived and re- 

 appeared as if it were bathing in the summer warmth along 

 the creeks in the valley below. 



These birds are tough little fellows, and I could never 

 understand why, when one was standing on a rock, its legs 

 would suddenly drop as if somebody had crept up behind 

 and hit the joints so that the body sank an inch or so. Then 

 the legs would straighten and bring the bird back to its nor- 

 mal position. This action was repeated several times a min- 

 ute. The only time I have seen the bird when it was not 

 bobbing was when it slept on a rock in the stream. It is no 

 seasonable performance connected with display and court- 

 ship. Males and females, spring and fall, follow this practice. 

 Among all the teetering and bobbing birds the style of the 

 dippers seems the most unique, perhaps because it is usually 

 done in the open against a contrasting background, or be- 

 cause the dark chunkiness of the bird seems ill-suited to such 

 contortions. 



Why do these birds of various types teeter and bob? I sus- 

 pect, at this moment, many people might suggest that, al- 

 though it is interesting to hear of the strange movements of 

 these birds, there isn't much point in trying to determine 

 why they make them. 



It is a comfortable and relaxing suggestion but one with 

 which the scientist just can't agree. Science does not progress 

 by overlooking the things that might be called small and 

 unimportant. Problems which are ignored because of their 

 apparent insignificance may prove to be of great moment 

 once they are explored. A small beginning like the examina- 

 tion of a sterile area in a culture medium led to the discovery 

 of penicillin. Only continued inquiry into seemingly unre- 

 lated details developed the commercial use of rubber. And 



