No. 4.] DECREASE OF BIRDS. 509 



its young on birds, and will kill birds as large as a jay. It 

 is often mobbed by jays, but not infrequently strikes one 

 of its tormentors, when all the rest % oif, leaving the hawk 

 to finish its victim. 



Probably most of the birds now killed by haAvks in Mas- 

 sachusetts are struck down by these two species. Some- 

 times in the fall these birds may be seen in great numbers 

 migrating south. jVIr. W. S. Perry estimates that he saAv 

 at least one thousand, mostly sharp-shinned and Cooper 

 hawks, going south Oct. 10, 1892. He watched them living 

 all day. He estimates that each bird will eat on the average 

 two small birds each day, or seven hundred each year. At 

 that estimate, the one thousand hawks which came within 

 the range of his vision would eat seven hundred thousand 

 birds a year. I regard these two birds and the goshawk as 

 the only hawks that should be shot by gunners, most others 

 being a positive benefit, or so rare as to do little harm. 



The pigeon hawk, also a l)ird hawk, is not conmion, and 

 the sparrow hawk feeds chiefly on insects. The broad- 

 winged hawk seldom kills birds, and the marsh hawk feeds 

 mainly on small mammals in most localities. 



The Blue Jay. — The blue jay, a smaller cousin of the 

 crow, has a similarly unsavory record, and also merits it. 

 It attacks the eggs of birds from the size of the smallest 

 sparrow and warbler to that of the robin. The robins, if at 

 hand, will successfully defend their nests ; but the ja}^ will 

 watch, and sometimes eventually appropriates the eggs in 

 the robin's absence. The jay pays little attention to the 

 screaming and protesting vireos, but robs their nests as un- 

 concernedly as though the parent birds were not present. 

 When jays have 3'oung in the nest, they sometimes watch 

 the nests of the smaller birds very closely. Hardly is a 

 clutch laid when it disappears, and most of the smaller birds 

 lose at least one set of e^<^i^. I am aware that many people 

 find it hard to believe that such a i)rettv bird as the blue jay 

 can be such a rascal ; therefore, I will not ask belief for my 

 own assertions without producing evidence to support them, 

 for the mere fact that twenty-six observers believe the jay 

 to be a destructive enemy of the smaller birds may not be 



