191-1] Bryant: Economic Status of the Western Mcadowlark 485 



ciently so well any unpleasant sensation that they usually avoid 

 a recurrence. 



Under such circumstances, we should naturally expect that 

 most of the birds taking; protected insects, etc., would be young 

 and inexperienced birds. In the present investigation juvenal 

 birds have been differentiated from adults as far as possible. 

 Consequently evidence on this point is available. Contrary to 

 expectation, most of the birds taking protected insects and other 

 arthropods as food have been adult birds. Tlieir previous ex- 

 perience with this kind of food is unknown. The simplest expla- 

 nation is to say that birds in searching for food take that at hand 

 and that most easily obtained. 



The only evidence afforded by this investigation that birds 

 learn to let certain insects alone is the total lack of eoccinellid 

 beetles in the food of the western meadowlark. In California 

 at certain times of year eoccinellid beetles are extremely common 

 and certainly would form an available food for the meadowlark 

 if they were not protected from attack. The chrysomelid beetle, 

 Diabrotica soror, a beetle sometimes confused with coccinellids, 

 is occasionally taken as food. One stomach was found completely 

 filled Math these beetles. Hence it would seem that birds can 

 distinguish between coccinellids which appear to be noxious and 

 certain chrysomellids which appear to be edible. They also dis- 

 tinguish between pentatomids with a noxious secretion and cocci- 

 nellids with a similar secretion. 



Movement is a very important factor connected with the 

 problem. Allen (1912) and Roosevelt (1911) have emphasized 

 this point of view, that any coloration is protective only so long 

 as the animal is motionless. Allen goes .so far as to say that 

 "coloration is a minor asset in an animal's protection in com- 

 parison with its other qualities — alertness, truculence and other 

 traits that make for its protection." This point of view has 

 received far less emphasis than its importance justifies. 



The highest expre.ssion of vision is to be found in birds. The 

 color sense, especially, is very acute, as shown by the preponder- 

 ence of cones in the retinal elements. The range and rapidity 

 of accommodation in birds far exceeds that of man or other 

 animals, and the accommodative and refractive apparatus is much 



