r 
Grid Species Accounts 
Nine division shorthand notations used here are similar to those 
discussed in the ECS #10 report. 
r>-La.'w 
k-footed Albatross (Diomedea nigripes) # Obs. = 31 - 
Por the bulk of bird species observed on the grid it is practic- 
1c 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 presenta¬ 
tions of the data, in fact, assume this automatically. The albatross 
data are, however, the glaring exception, and since they are so dis¬ 
similar 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-^ and 
5 respectively. 
j 
rrn 
r . J. 
na 
hie 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 
at coverage from late May to mid-July does not document it well. 
late July, EGS #10, to the present survey a regular decrease 
■ been veil 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 immature s have fledged from 
the breeding grounds and should be showing up off the California 
coast to produce a winter peak perhaps about December. Evidently 
there is a decrease after this time due to some factor such as intol- 
