The Zoologist — September, 1866, 361 



Letters o?i Ornithology. By Harry Blake-Knox, Esq. 



Letter II.— British LARioiE. 

 Subfamily Xema. Species Larus ridibundus and L. capistratus. 



A Natural History of the Brownhooded or Blackheaded Gull, with 

 an Account of all its Plumages and Transformations from the 

 Nestling to the Adult Bird; also some Questions about the 

 Masked Gull. 



Habits.— The brownhooded gull, the only bird of its family that can 

 be said to be indigenous to Ireland, or in fact to the British Islands, 

 (as I believe neither the masked gull nor any other of the dark headed 

 gulls have been found breeding in the United Kingdom), is both a 

 marine and an inland bird. Throughout the autumn and winter it is 

 very common on our eastern coast, and being gregarious is seldom 

 met with alone. From the middle of March it grows scarce on the 

 sea, both the adult and young birds retiring inland, the former for the 

 purpose of conserving their species, the latter prompted by a latent 

 instinct to visit those haunts of their parents at this season, so that in 

 after years they themselves may not be strangers to them ; however, 

 be this as it may, both young and old leave the sea from the middle of 

 March, returning again with the young birds of the year in July. As 

 this bird positively does not breed till three years old, as I will here- 

 after show, I can form no other opinion but that an impulse of Nature 

 causes them to leave the sea, or that the young do so in imitation of 

 the adults, and that at a lime too when the sand eels are most 

 abundant in the Bay. Sometimes, however, flocks visit their old 

 winter feeding-grounds during summer, and these flocks, though to 

 the uninitiated looking like adults, are composed of two-year old 

 birds, or the unmistakable young of last year. Thompson has also 

 seen these seemingly adult birds in flocks during summer far from any 

 breeding-station, and strangely considered them "barren" birds, 'as 

 we also read of the kiltiwake at this age being considered barren, not- 

 withstanding the immature aspect of the genital organs and the bastard 

 wing still marked with black at two years old, in both kittiwake and 

 blackheaded gulls, whereas the spurious wing of the kiltiwake in the 

 adult is pure blue, in the blackheaded gull pure white. " From the 

 River Lagan," says that true naturalist Thompson, " they used to be 



SECOND SERIES — VOL. I. 3 _4 



