Western Gull (Larus occidentalis ) 
Adults and immatures were observed along the east shore of Guadalupe 
Island and off the north coast of Ba.ja California. 
Herring and California Gulls ( Larus argentatus and L. Californicus ) 
Immatures were seen along the Baja coast as far south as Cape San 
Lucas.; adults were seen only to the north of Magdalena Bay. 
Bonaparte's Gulls ( Larus Philadelphia ) 
Seen almost exclusively off Magdalena Bay on 1 December. During the 
early morning immatures were seen in a ratio of 2 to 3 adults (N= 29 )> but 
during the late morning and afternoon no immatures were seen among the 56 
for which age was observed. 
Black-legged Kittiwake ( Bissa tridactyla ) 
Seen in low numbers off Magdalena Bay. 
Sabine f s Gull ( Xema sabini ) 
Seen most commonly on 1 December off Magdalena Bay, but also seen 
along the coast as far south as Acapulco. 
Sooty Tern ( Sterna fuscata ) 
In terms of numbers this was the second most abundant species identi¬ 
fied on the cruise. However, most of the birds in the tally were in flocks 
and the number of sightings was small. Both adults and immatures were seen 
in a 400 mile wide band between Clipperton and the Galapagos Islands, but 
no immatures were recorded on other portions of the cruise. The Sooties 
off Manzanillo and at the mouth of the Gulf of California were in fresh 
plumage with long tail feathers suggesting that they were nonbreeding 
birds. Elsewhere no adults were seen well enough to determine the plumage 
condition. 
ADDITIONAL BIRD OBSERVATIONS 
A distant flock of ca. 5000 birds believed to have been storm petrels 
was seen off Magdalena Bay, Baja Peninsula. Because this sighting was 
unique and its reliability questionable, it has not been included in this 
report excepting in the overall tally of seabirds in the introduction, and 
in table 1. 
Landbirds 
Landbirds were seen frequently on some parts of the cruise. A summary 
may be found in table 4. 
MAMMAL SIGHTINGS 
Mammals were scarce-during the cruise; a summary of sightings is 
