262 BIRDS OF PENNSYLVANIA. 



along- the roadside, and were from ten to twelve feet above the ground. 

 One nest contained five fresh eggs ; parent bird setting on nest. When 

 I was securing this nest and eggs the old birds flew near me uttering 

 sharp, rasping cries. The notes of the young shrikes are not unlike the 

 squeak of a mouse. Indeed, my friend Mr. Sennett, yesterday when I 

 was killing the young we had captured, stepped on a strap, and hearing 

 the squeaky voices of the birds in my hand, thought at first that he had 

 trod on a mouse. When taking the nests of shrikes which contained 

 young, the old birds were quite bold, and when the squeaky cries of the 

 young were heard, they flew directly at my head, but after finding it im- 

 possible to drive me away by these attacks they alighted close by, and 

 remained silent witnesses to the despoliation of their treasures, which 

 were soon secured by me, and then both the old birds were shot. When 

 feeding these birds repair to fence-rows, bushes in fields and along the 

 margins of woods or thickets ; they also frequent grass fields and mead- 

 ows and perch on fences or tall weeds, and they likewise visit plowed 

 grounds in quest of food. They sometimes hover over their prey in a 

 manner very similar to the Sparrow Hawk (Falco sparverius). The race 

 known as the White-rumped Shrike (Lanius ludovicianus excubitorides, 

 Swains.), is very similar to the Loggerhead, from which it differs chiefly 

 in being paler above, more like borealis, and with whitish rump and 

 upper tail-coverts ; and it is stated that the wings, tail and tarsus average 

 a little longer, and the bill a trifle smaller than in the Loggerhead. 



FAMILY VIREONID-ffi. VIREOS. 



THE VIREOS OR GREENLETS. 



These birds frequent chiefly woods and thickets, yet some, particularly the Red. 

 eyed and Warbling, are common during migrations about yards and gardens in 

 towns. Both of these species also often breed in the trees of parks and gardens. 

 The Vireos are rather plainly attired, and were it not for their delightful and musi- 

 cal notes, they would much oftqner escape our notice than they do ; few of our woods' 

 birds are equal to them as songsters. They live almost constantly in the leafy 

 retreats of trees and shrubbery, rarely, if ever, do they rest on the ground. They 

 subsist almost exclusively on insects, chief among which maybe mentioned flies, 

 spiders, beetles and various larvae ; in the late summer and autumn some species 

 feed to a small extent on a few kinds of berries. We have in Pennsylvania six 

 species, viz : the Red-eyed, Warbling, Blue-headed, Yellow-throated, White-eyed 

 and Philadelphia Vireos, and all, with the exception of the Philadelphia Vireo, are 

 common as summer residents or spring and fall migrants. Their beautiful cup- 

 shaped, or basket-like and pendulous nests, are composed of pieces of bark, lichens, 

 rootlets, fine grass stems, bits of paper, etc., and suspended from forked twigs. 

 Vireos nest in trees and bushes, usually in groves or forests ; some build close to the 

 ground ; others erect their pensile homes on the highest twigs of tall forest trees. 

 Their elongate-ovate eggs, commonly live, are white, thinly speckled or dotted, 

 usually about the larger end with black or brown. They measure generally a little 

 more than three- fourths of an inch long by half an inch wide. The Red and White- 

 eyed Vireos breed abundantly with us, and in a large proportion of their nests, 

 especially in nests of the Red-eyed species, you will find Cowbirds' eggs or young. 



