BIRDS OF ESSEX COUNTY. 89 



livers or other refuse — are thrown out to attract the fish to the spot. Of this 

 custom the Kittiwakes — or 'Pinny Owls,' as these men invariably call them — 

 are well aware, and swarms of them quickly collect around the boats to pick up 

 the morsels before they sink. They are very tame, and if one of the flock is 

 shot the others hover over it as Terns will do on similar occasions. The usual 

 way of taking them, however, is with hook and line, the bait being allowed to 

 float off on the surface, when it is quickly seized by one of the greedy horde. 

 In this manner great numbers are annually taken by the fishermen, who either 



skin and stew them or use the flesh for bait When the catch has been a 



large one, and the work of cleaning the fish is continued at the anchorage, they 

 [the Kittiwakes] remain about the spot for hours picking up this offal directly 

 under the sides of the vessels." 



Although Kittiwakes are considerably smaller than Herring Gulls, it is easy 

 to be deceived and mistake one for the other unless the two birds are near 

 together. The Kittiwake is generally more graceful and active on the wing, a 

 more rapid flyer, and when one has become accustomed to the two species they 

 are easily distinguished. This I found to be the case when sailing off Rockport 

 in winter, and the fishermen who have taken me out, rarely made a mistake in 

 pointing out " Winter Gulls," as they called the Kittiwakes. 



A capital point which I have made out in adult Kittiwakes as they flew 

 overhead is the fact that the bases of the black tips of the primaries are in 

 straight line, instead of extending farther up the feathers in the larger primaries 

 as is the case in Herring Gulls. In the immature Kittiwakes, however, this dis- 

 tinction does not exist, as there is much black in all the large primaries. The 

 differences between this Gull and Bonaparte's Gull will be discussed under the 

 latter bird. The rudimentary hind toe without a nail is not revealed, unfortu- 

 nately, until the bird is in our hands. The bird referred to above, shot on Sep- 

 tember 6th, 1903, had a much more noticeable hind toe with a minute nail, and 

 suggested the western form, Rissa tridactyla pollicaris. An examination of a 

 series of skins of our eastern bird shows, however, a considerable variation in the 

 size of this toe. 



15 [42J Larus glaucus Briinn. 

 Glaucous Gull ; Burgomaster. 



Very rare winter visitor. 



At the Peabody Academy, in Salem, there are two specimens of this Gull, 

 one immature labeled Essex County, 1856, S. Jillson, the other taken at Lynn 



