468 GAME BIBDS OF CALIFOENIA 



intruder, instead of flushing close at hand, as in the case of less 

 strikingly colored species. It would appear as though the Killdeer 

 in its combination of conspicuous pattern of coloration and blatant 

 behavior shows a peculiar specialization for distracting attention from 

 its eggs and young. 



The first plumage, of down, is gradually replaced by a juvenile 

 plumage closely similar to that of adults ; but shreds of down often 

 remain adhering to the tips of the tail feathers until late fall. The 

 juvenile plumage is retained by the Killdeer through the first winter 

 and on into the spring of the year following that in which it was 

 born. In the fall the young can be distinguished from the adults by 

 the frequent adherence of down to the tips of the juvenile feathers, 

 as just described, by a slightly more rusty tipping of the feathers of 

 the back, and by the white of the neck collar in front being suffused 

 with light brown. 



The flight of the Killdeer is quite erratic ; the bird frequently dips 

 and dives in a most bewildering manner, sometimes descending head- 

 long nearly to the ground in almost vertical flight. As already stated, 

 flocks of Killdeer do not show the same compact formation nor do 

 the birds move together in unison as in the case of many other shore 

 birds. 



The Killdeer is, without a doubt, from an agricultural standpoint 

 the most beneficial of our shore birds. This valuation rests upon 

 the nature of its food and upon the commonness of its occurrence on 

 cultivated lands. According to McAtee and Beal (1912, pp. 16-18), 

 beetles form 37.06 per cent of its food, other insects 39.54 per cent, 

 and other invertebrates such as centipedes, spiders, ticks, oyster 

 worms (Nereis), earthworms, snails, and crabs and other crustaceans, 

 21.12 per cent. Some of this food is obtained by probing in muddy 

 places as with other plovers, but the greater portion of the food is 

 secured by surface-gleaning. Vegetable matter constitutes only 2.28 

 per cent of the food and is made up chiefly of weed seeds. Very 

 many of the species of insects forming the diet of the Killdeer such 

 as grasshoppers, weevils, wireworms, and army worms, are classed 

 as important enemies of various crops. During a plague of grass- 

 hoppers in the summer of 1912 at Los Bafios, Merced County, H. C. 

 Bryant (1914a., p. 170) found a single Killdeer 's stomach to contain 

 eleven grasshoppers and nothing else. 



While it is possible that the Killdeer was a more abundant species 

 in past years than at present, it is obvious that it has not shared with 

 other shore birds the decided diminution in numbers which they have 

 suffered. The species is abundant in a great many localities in the 

 state, and, witli the present favorable attitude on the part of most 

 farmers, will probal)ly continue so indefinitely. Its wide breeding 



