BIRDS Of 1 PENNSYLVANIA. 11 



spotted or blotched with different shades of brown and grayish. Dr. Elliott Coues 

 says: "The Skua Gulls are eminently rapacious, whence their name of 'Jager' 

 (hunter) ; they habitually attack and harass terns and the smaller gulls, until these 

 weaker and less spirited birds are forced to drop or disgorge their prey. Their flight 

 is vigorous ; lashing the air with the long tail, they are able to accomplish the rapid 

 and varied evolutions required for the successful practice of piracy. Thus in their 

 leading traits they are marine Raptores, whilst the cered bill furnishes a curious 

 analogy to the true birds of prey." 



Thomas Nuttall, writing of the Jaegers, says : " They also often provide for them- 

 selves, feeding on floating objects, as they never dive, and sometimes live on the 

 flesh of cetaceous animals, shell-fish, molusca, eggs and young birds." The head 

 and eyes are large ; neck rather short and stout ; bill strong, hard and hooked at tip ; 

 "covering of the upper bill not entire, as in the Laridce, the posterior half being 

 furnished with a horny cere, the lower edge of which overhangs the nostrils ; toes 

 fully webbed ; hind toe very small ; claws large and strong, curved and very acute ; 

 tail slightly rounded, but the central pair of feathers projecting a greater or less dis- 

 tance beyond the rest." 



The Jaegers like the Gulls and Terns (Laridse) swim most buoyantly, but are 

 incapable of diving. Representatives of this family, both adult and young, vary 

 greatly in their plumage. 



GENUS STERCORARIUS BRISSON. 

 Stercorarius pomarinus (TEMM.). 



Pomarine Jaeger. 



DESCRIPTION. 



"Adult. Front, crown of the head, back, wings and tail, blackish-brown; sides 

 and back part of the neck bright-yellow; throat and entire under plumage white, 

 with a brand of brown spots extending across the upper" part of the breast; sides 

 and lower' tail coverts barred with brown ; shafts of quills and tail feathers white; 

 bill greenish-olive, black at the tip ; legs and feet black ; the middle tail feathers 

 extend beyond the others for about 2 inches ; they are rounded at the end, and of a 

 uniform breadth throughout. 



" Young birds have the plumage of the upper parts blackish-brown ; of the lower, 

 grayish-brown, with the feathers of the abdomen and lower tail coverts margined 

 with dull-ferruginous ; tarsi and base of the toes and webs yellow. " Baird's B. of 

 N. A. Length about 20 inches ; extent about 48 inches. 



Habitat. Seas and inland waters of northern portions of the Northern Hemi- 

 phere, south in winter to Africa and Australia and probably South America. Not 

 known to occur in winter on the Atlantic coast of North America north of Long 

 Island. 



The Pomarine Jaeger, known to the fisherman on the coasts of Maine 

 as " Gull Hunter," resides during the summer or breeding season in 

 high boreal regions, but when the young are able to provide for them- 

 selves both the old and young migrate southward, and frequent mainly 

 the shores of the ocean. In this state the Jaeger occurs only as an acci- 

 dental visitor. The late Prof. S. R Baird, in the summer of 1840, secured 

 a specimen at Harrisburg, on the Susquehanna river ; another example 

 of the same species is recorded as having been obtained by the late Vin- 

 cent Barnard, of Chester county, in Lancaster county, Pa., on the Susque- 

 hanna In the winter of 1885 or 1886, Mr. C. D. Wood, a Philadelphia 



