18 cUCKOOS AND SHRIKES IN RELATION TO AGRICULTURE. 
destroyed by the butcherbirds, if allowed to live, would have amounted 
at the end of the first year to 118,800, and at the end of the second year 
to 1,306,800 individuals. The shrike is at work every winter in the 
cities of the northern tier of States, killing the sparrows which tend to 
increase until they become so abundant that more are obliged to resort 
to the country for food. In a number of instances where English spar- 
rows had been devoured, their stomachs, containing seeds and gravel, 
were found within the butcherbirds’ stomachs. A golden-crowned 
kinglet’s stomach also was detected, filled with fragments of a beetle 
and scores of tiny gnats. Mr. Frank M. Drew, in an article entitled 
‘Field Notes on the Birds of San Juan County, Colorado’ (Bull. Nutt. 
Ornith. Club, vol. 6, p. 89), says that this sbrike lives by foraging on 
little troops of titmice. Dr. G.S. Agersborg, of South Dakota, states 
(The Auk, vol. 7, p. 279) that it seems to follow the wake of the tree 
sparrows (Spizella monticola), and leaves in the spring at the same time 
they do. Prof. F. E. L. Beal while at Ames, Iowa, noted the butcher- 
bird attacking birds only once, although he had time and again recorded 
their killing mice. In this exceptional case the victim was a downy 
woodpecker (Dryobates pubescens) which the shrike had hung in a crotch 
while devouring the brains. The most remarkable account of the 
butcherbird’s not molesting birds also comes from Professor Beal at 
the same station. A shrike was perched on a telegraph wire above 
a rank weed patch which was all a-twitter with hundreds of native 
sparrows. Every now and then the shrike would leave the wire to 
scour the prairie, apparently hunting for mice, and then return to his 
perch. He paid no attention to the sparrows, and they showed no 
signs of apprehension. 
Following is a list of birds that the butcherbird has been known to 
kill: 
Chickadee (Larus atricapillus),! 
Bush tit (Psaltriparus). 
English sparrow (Passer domesticus).: 
Tree sparrow (Spizella monticola).? 
Snowflake (Plectrophenax nivalis), 
Downy woodpecker (Dry yotates pubescens). 
Vireo (Virco sp.). 
Junco (Junco hyematis).? 
Kinglet (Regulus satrapa).? 
Field sparrow (Spizella pusilla). 
Goldfinch (Spinus tristis).2 
Siskin (Spinus pinus).? 
Yellow-rumped warbler (Dendroica coronala).? 
Mourning dove (Zenaidura macroura). 
Cardinal (Cardinalis cardinalis), 
Longspur (Calearius). 
Shore lark LEO: ‘ 
“Identitied in the laboratory. 
'Dr. J. Dwight, jr. 
* Ornithologist and Oologist. 
