4. Grid Species Accounts Nine division shorthand notations used here are similar to those discussed in the EGS #10 report. Black-footed Albatross (Diomedea nigripes) # Obs. = 31. For the bulk of bird species observed on the grid it is practicable to assume that the sightings correspond to a set of fixed positions and the ship and observer move through this static field without affecting the distribution of the set. All the statistical presentations of the data, in fact, assume this automatically. The albatross data are, however, the glaring exception, and since they are so dissimilar to the remainder of the observations I have eliminated them entirely from the standard tables and tallies. The albatross data for Eastern Grid Surveys 1-13 are summarized on Charts Numbers 1 and 2 and as follows. One hundred days or parts of days have been spent in the grid area. From 1 to 19 birds were recorded following the vessel each of these days. The maximum daily count, (the highest number recorded in one sighting), is the least subjective datum that can be given for one day's observations. The frequency histogram in Chart No. 1 indicates that the mode for 93 tabulated days is three birds. Due to the skewed nature of the distribution both the mean and median are somewhat higher, 5.4 and 5 respectively. The numbers in the 13 squares in Chart No. 1 are representations of maximum daily counts for each of the nine grid subdivisions. They were derived fairly subjectively from a rough mean of maximum daily counts recorded in each subdivision. Circled figures indicate areas of higher numbers on each survey. The combined average demonstrates their overall tendency for concentrations in the northeast part of the grid area. Chart No. 2 shows the means and medians of all grid surveys. Between March and July an overall increase is apparent, but cant coverage from late May to mid-July does not document it well. From late July, EGS #10, to the present survey a regular decrease has been well documented. Eastern Grid Survey #1 is the only information available for the months October through January and it suggests that in addition to a summer high there is also a winter peak. In relation to the breeding phenology I offer the following explanation of the bimodal abundance curve. During August, September and October adult birds are in the process of returning to the Central Pacific breeding grounds leaving peripheral areas (such as the Eastern Grid) and resulting in the late summer decrease that is currently underway. At least by early November when most of the breeding population has returned to the islands, I expect the grid numbers to level off. In September most of the immatures have fledged from the breeding grounds and should be showing up off the California cost to produce a winter peak perhaps about December. Evidently there is a decrease after this time due to some factor such as intol-