380 
PACIFIC SCIENCE, Vol. IX, October, 1953 
TABLE 2 
Average Albatross Counts and Plankton Volumes for Cruises 1 to 5 
BLOCK NUMBERS 
REGION 
MEAN NUMBERS 
OF ALBATROSSES 
MEAN VOLUMES 
OF PLANKTON 
7-9 
Northern Calif. 
19 
214 
10-12 
Central Calif. 
20 
141 
13-15 
Southern Calif. 
4 
65 
16-18 
Baja Calif. 
2 
48 
this line and the coast were associated with 
decreasing sea temperatures. Thompson also 
noted a direct relationship between the num- 
bers of jellyfishes, observed by luminescence 
in the ship’s wake at night, and the numbers 
of albatrosses counted during the day. He 
reasoned that jellyfishes, and hence alba- 
trosses, were most abundant in the colder, 
more productive waters. 
No consistent relationship between the 
total plankton volume in a standardized net 
haul and the numbers of albatrosses seen at 
the same station was observed on the 1949 
and 1950 cruises. In a general way, however, 
the blocks in which the highest average num- 
bers of birds were recorded were those in 
which the greatest average plankton volumes 
occurred. As illustrated in Table 2, the num- 
bers of albatrosses and the volumes of 
plankton per unit volume of water 3 were 
greatest off the northern California coast, and 
least off southern and Baja California. It is 
not known whether this association indicates 
a causal relationship. 
It is tempting to search for relationships 
between the pattern of albatross abundance 
and the distribution of the various physical, 
chemical, and biological factors recorded at 
the hydrographic stations. The albatross 
counts presumably are not subject to the 
criticism that is levelled at counts of plankton 
and other marine organisms, namely, that 
they represent only the standing crop, for 
3 The plankton volumes were taken from an un- 
published mimeographed summary prepared by the 
staff of the South Pacific Investigations of the U. S. 
Fish and Wildlife Service. 
these birds are almost completely free from 
predation while at sea (Miller, 1940; Yocom, 
1947; McHugh, 1952). Nevertheless, strong 
and apparently highly significant statistical 
correlations can be obtained even with ran- 
dom numbers by trial and error methods. 
Inasmuch as there is no good biological evi- 
dence to suggest that albatross abundance 
and any of the physical, chemical, or biolog- 
ical factors are related, no correlations were 
sought. 
In former years, when it was more abun- 
dant, the Pacific sardine ( Sardinops caerulea) 
performed an annual migration from Califor- 
nia waters to summer feeding grounds off the 
Pacific Northwest, sometimes ranging as far 
north as southeastern Alaska. There is in- 
direct evidence, particularly in the 1949 ob- 
servations, that the Black-footed Albatross 
performs a similar seasonal migration north- 
ward along the coast. If such a migration does 
occur, it may be in response to similar stimuli. 
Continued study of the distribution and 
movements of these birds may provide valu- 
able clues to the question of varying sardine 
abundance and availability. 
SUMMARY 
Counts of Black-footed Albatross were re- 
corded at all stations occupied during day- 
light on cruises of the California Cooperative 
Sardine Research Program in 1949 and 1950. 
The survey area was divided into blocks, and 
the counts per station within each block were 
averaged to derive indices of abundance. 
Birds were most abundant off California and 
Baja California during the spring months, and 
