Birds in Bering and Chukchi Seas — Swartz 
pelagic bird observations were made, is shal- 
low with a relatively featureless bottom (Fig. 
2). In the area sampled, few depths exceed 
35 fathoms. Current and temperature patterns 
are complex. In general, current flow is north- 
ward through Bering Strait (Fig. 4). Patterns 
of current flow in the northern Chukchi Sea 
seem to be affected strongly by winds. Tem- 
perature patterns at 5-m depths are shown in 
Figure 5. The invertebrate fauna is rich and 
abundant, but fishes are not conspicuously 
abundant in either species or individuals, 
though of course their numbers are adequate 
to support sea bird colonies in apparent pros- 
perity (Swartz, 1966). 
ACKNOWLEDGMENTS 
Dr. R. H. Fleming, of the University of 
Washington, offered to place a man aboard 
the University of Washington research vessel, 
"Brown Bear," to observe sea birds during a 
portion of its I960 oceanographic cruise 
(Brown Bear Cruise 268). Mr. E. J. Wil- 
loughby was selected to be the observer and 
deserves great credit for the zeal and accuracy 
of his work. The cooperation of Dr. Fleming, 
the crew, and the research staff of the "Brown 
Bear” is gratefully acknowledged. 
Willoughby’s activities were financed to a 
major degree by a program directed by F. S. L. 
Williamson of the Arctic Health Research 
Center. I am greatly indebted to Mr. William- 
son for permission to include in this paper the 
observations on species not breeding at Cape 
Thompson. These species were initially in his 
province and this paper could not have had its 
present form without his generous cooperation. 
PROCEDURE 
The portion of the cruise track of the 
"Brown Bear" which is included in this paper 
is shown in Figure 3. Willoughby boarded the 
"Brown Bear” on August 6 near Cape Thomp- 
son and disembarked at Nome on August 28. 
Most observations were made from the fly- 
( ing bridge where the view in all directions was 
relatively unobstructed. In order to achieve an 
objective index of abundance and movements, 
10-minute-long counts of all birds seen and 
333 
records of their activities were made at inter- 
vals throughout the 24-hour period. Detailed 
observations were continued between the 10- 
minute counts to the extent permitted by 
weather, visibility, and the endurance of the 
observer. Over 600 entries pertaining to sea 
birds were made in addition to 10-minute 
counts. Latitude and longitude are known for 
each entry. Observations including time, posi- 
tion, surface temperature of the sea, wind speed 
and direction, wet and dry bulb air tempera- 
ture, barometer readings, precipitation, size and 
direction of swell, and approximate visibility 
were recorded several times a day from routine 
readings made by Willoughby and other ship 
personnel. All of these data were examined 
and those which proved meaningful in inter- 
preting the avian observations are discussed at 
the appropriate place. Since conditions of visi- 
bility varied widely from day to day, no effort 
was made to convert the data to absolute abun- 
dance per square unit of sea surface as was 
done by Kuroda (I960). 
During the same interval that Willoughby 
was making observations at sea, a shore party 
was conducting investigations of the large col- 
onies at Cape Thompson. It was hoped that 
comparisons of behavior at the breeding cliffs 
with offshore observations would yield signifi- 
cant information not otherwise obtainable. 
With the exception of the expected observa- 
tion that departure of flocks from the cliffs 
produced a rise in numbers observed at sea, 
this hope was not realized. 
RESULTS 
Below, listed phylogenetically, are discus- 
sions of distribution, abundance, and move- 
ments of birds seen from the "Brown Bear.” 
Unless specifically noted, all species were pre- 
viously observed in the Bering or Chukchi seas 
by Jacques (1930) or Shuntov (1961), the 
only authors who have published substantial 
offshore observations which overlap those re- 
ported here. 
Loons (Gavia sp.) 
Two sightings of unidentified loons were 
made, both close to shore (Fig. 6). Four of 
these birds were seen at 69°46'N, 163°17'W 
