Herring Gull (larus argentatus) Undoubtedly the most common large gull found in the grid season was the Herring Gull. Despite periodic checks of the following the ship, no species other than herring and glaucous-winged gulls were found doing so. This is in contrast to specific composition of gull populations in equivalent latitudes along the coast (where the california gull predominates). All the large gulls seen in the grid followed the ship for hours, and one distinctively marked bird was noted to be present for at least eight hours. The age composition of those following the ship averaged approximately 50 per cent adults, the rest were immatures and sub-adults. This would suggest that gull birds have a greater pelagic wandering tendency as the age ratio in a normal population would be predominately adult birds. Two specimens were collected. Black-legged Kittiwake (Rissa tridactyla) This was the most abundant species throughout the grid during this survey. Density declined from north to south. Age composition predominately immature birds (67 percent immatures in the northern third, 100 per cent immatures in the southern third). Apparently, the grid includes a pelagic border of the range for this species. This is suggested both by the density distribution (see Table 2) and age distribution. Two specimens were collected. Xanthus Murrelet (Endomychura hypoleuca) Two birds were sighted during the survey. Rhinoceros Auklet (Cerorhinna mononerata) All sightings of this species were in the northern two-thirds of the grid; most were of swimming birds. It should be noted that the density figures for the alcids are not comparable to the other species for two reasons. First, they spend most of their time in the water where observations are difficult. Secondly, because they spend considerable time diving, they often go unseen. Thus density figures should be used as an index only within the alcid group. Three specimens were collected. Grid Summary As may be seen from Table 2 and the species accounts, the grid seems to include the pelagic range border for several bird species, whether this is due to ocean currents, isotherms, or is in fact a