WISCONSIN BIRD-STUDY BULLETIN. 25 



birds' eggs, says that he has never seen a punctured cowbird's egg. 

 He also reports that the cowbird frequeutly wastes her own eggs ijy 

 placing them in old unused nests and by dropping them into new 

 nests before the owner has deposited her own eggs. In the latter ease 

 the owner of the nest often abandons it. Sometimes a nest is aban- 

 doned after the clutch is partly laid if visited by the cowbird. It is 

 commonly thought that the cowbird never lays more than one egg in 

 a nest. Mr. Bendire has found that as many as seven have been laid 

 in the nest of the oven oi* teacher bird, and that this and other ground 

 building birds are most frequently imposed on in this way.* 



Another interesting thing is that the egg of the cowbird hatches in 

 less time than the eggs with which it is laid. As a result the cow- 

 bird's chick has a day or more the start of the rightful occupants of 

 the nest. Being usually larger than the others to start with, and 

 having the advantage of growth for a day or two, it is not strange 

 that the big imposter should either smother the others or starve them 

 by appropriating all the food, or crowd them out of the nest to die 

 of hunger and cold. The very unpleasant truth is that none of the 

 nestlings of any of the small birds imposed on by the cowbird ev3r 

 live more than a few days. The foster parents do not desert the ne=*, 

 however, even though the young cowbird is the only one left. They 

 work harder in trying to satisfy the hunger of this big burly felio"-' 

 than they would have done in rearing a whole brood of their own litt'e 

 ones. 



Think of a little chipping sparrow trailing around a big, full-grown 

 cowbird, that, like Oliver Twist, is always asking for more and is never 

 satisfied. The patient little foster parents work harder and harder 

 as though they were proud of their, "ugly duckling" and expected 

 great things of it, imtil finally, it finds that it can take care of itself, 

 turns the cold shoulder on its benefactors, and joins a^ flock of it^- 

 own kind assembled from a great -variety of nests. The soft-voiced 

 mourning dove and- the gentle cuckoo have their representatives tj 

 that flock. The red-headed woodpecker and the tyrani; kingbird, the 

 flycatchers and blackbirds, the bobolink and the orioles, the meadow 

 lark and the goldfinch, the sparrows, thrushes, vireos and warblers - 

 all have sent delegates to this cowbird convention. 



^Life Histories of North Am.erican Birds, vol. 2. 



