512 NOTES ON SOME OF THE 



ever, seem actually fixed at all seasons, and are really essen- 

 tially non-migratory, as the Spruce Partridge, and Quail 

 ( Ortyx Virginianus) are in New England. But only a small 

 proportion, doubtless, of the so-called non-migratory birds 

 at any given locality are really so.* 



In connection with this topic of migration, the fact that 

 some of the young or immature individuals of our marine 

 birds, as the Herring Gull (Larus argentatiis) and other 

 species of that family, and several of the Tringse, linger on 

 our coast during summer, while the adult all retire north- 

 ward, is one of some interest. Mature and strong birds 

 only, in species that breed far to the north, evidently seek 

 very high latitudes. Birds of the first year also appear to 

 roam less widely than the older. In different species of the 

 Gull family it is generally only the mature birds that in 

 winter are seen far out at sea, though in the same latitudes 

 the young may be numerous along the coast. All observant 

 collectors are well aware of the fact that those birds that 

 first reach us in the spring, of whatever species, are gen- 

 erally not only very appreciably larger, but brighter plum- 

 aged and in every way evidently more perfect birds than 

 those that arrive later ; and that in those species that go en- 

 tirely to the north of us there is a much larger proportion of 

 paler colored and immature birds, especially among the Sylvi- 

 colidce, or warblers, towards the close of the migrating season 

 than earlier. Hence the presence here of a few individuals 

 in summer of species that usually go farther north is not 

 always sufficient evidence that the species breeds with us. 



In reference to the notes which follow, they may be consid- 

 ered as forming a supplement, as already stated in a foot note, 

 to a "Catalogue of the Birds of Massachusetts" published 

 by me five years since. In the present paper seveft- species f 



* In respect to the proof whereon this proposition rests, see my remarks on this point 

 in the Memoirs of the Boston Society of Natural History, Vol. i, Ft. iv, p. 488 (foot 

 note). 



f Strix pratincola, Surnia ulula, Turdus naevius, Seiurus Ludovicianus, Centronyx 

 Bairdii, Micropalama himantopus, Pelecanus erythrorhynchus. 



