ZooL.— Vol. II.] LOOMIS— CALIFORNIA WATER BIRDS. 31I 



The association of old and young Broad-winged Hawks in 

 the autumnal flights in Connecticut^ tends to show that there 

 is no lack of experienced leaders in the migration of land 

 birds. 



It should be borne in mind, if the migrants occurring in 

 a locality are not seen in transitu, merely arrested migration 

 is witnessed, only birds that have halted at the station being 

 seen, extensive movements taking place unobserved. This 

 was well illustrated in the Loons May 27, 1897. In the 

 harbor at Monterey there were only a few individuals, and 

 these upon the water, while on the ocean several miles off 

 Point Pinos a migratory movement was under full headway, 

 numerous bands of black-throated birds passing swiftly by 

 on their way north. Hence the mere presence of young 

 transients alone in a locality, early or late in the migration, 

 does not prove they are migrating independently of the 

 adults.^ The true criterion is actual migration. 



Where young-of-the-year have been seen moving by 

 themselves near the land, as in the American Golden 

 Plovers mentioned by Mr. Mackay,^ I believe that there is 

 migration of adults going on at the time offshore, as in the 

 Loons just referred to, or else that the young have become 

 separated from their seniors during the journey,* eventually 

 to lose the way '^ if they do not fall in with some of their 

 own kin or with other species having the same route. It 

 may be the Black-bellied Plovers, September 24, sought the 

 companionship of the Dark-bodied Shearwaters because 

 they were lost. Not unlikely, young birds are sometimes 

 misled, and taken out of range." However, they are found 



1 Trowbridge, ' Auk,' Vol. XU, p. 262. 



2 When the young of any land species greatly outnumber the adults on the breeding 

 grounds, it may be questioned whether they are wholly natives, or largely stragglers 

 that have fallen out of the ranks, a little later to resume the march with other comrades. 



3 'Auk,' Vol. XIII, p. 91. 



4The separation in the Golden Plovers may have happened after the halt "in the 

 vicinity of Labrador" (1. c, p. 90). 



s Such a mishap apparently befell a juvenile Bonaparte's Gull at the end of May, 

 1897. Left behind by all his kindred, but seemingly in good health, I found him in com- 

 pany with some superannuated ' Mud-hens ' that had taken up their abode in a lagoon 

 near the Monterey harbor. 



6 Old birds, perchance driven from their course by storms, seem to miss their way at 

 times and wander to regions remote from the habitat of the species. A notable instance 

 is Swinhoe's Wagtail in Lower California (Proc. U. S. Nat. Mus., Vol. IV, p. 414). 



