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Transcription
Boundary area A -- roughly centered at day 4 (mouth of the Gulf of
California) is the approximate convergence area of the southeast-flowing
California Current and the west-flowing north Equatorial Current.
Boundary area C, determined at days 10-11 at about 9°N, is at the
region where the Equatorial countercurrent bifurcates to stream north and
south.
Boundary area B is evidently an area of upwelling caused by the north-
ward flowing tongue of the Equatorial countercurrent meeting the continental
shelf. It is evidently rich in food as large schools of tuna and "dolphin"
were associated with the bird flocks 10-20 miles off the coast. Some
current charts would lump these hypothesized A and B divisions as being the
two sides of a broad current transition area.
SPECIES ACCOUNTS
Black-footed Albatross
Total Observations - 17
One to six birds followed the ship for the first five days. Two birds
were seen last about 1200 of 3 June (22°30'N, 110°00'W).
Laysan Albatross
Total Observations - 1
One "White Goony" was reported by the chief engineer on 31 May. I
take the observations as valid.
Sooty Shearwater
Slender-billed Shearwater
Total Observations - 49
?
"Numbers" of Sooty Shearwaters were observed shortly out of San
Francisco and around Monterey Bay. None were recorded during 30 and 31 May,
perhaps due to the greater distance from the coast. Birds were fairly regu-
lar again off Baja, California, and down to about 15°N along the Mexican
cost. Sooties were regularly mixed in with the large Manx Shearwater flocks
and many were seen from the skiff on 5 June. With little hesitation I feel
95+ percent of the Sooty/Slender-bill types were indeed Sooty. A single
bird, glimpsed in a flock on 5 June, was probably a slender-bill; but this
was the only one observed during careful scrutiny of the Sooties.
Wedge-tailed Shearwater
Total Observations - 619
The first Wedge-tail appeared in boundary zone A at the mouth of the
Gulf of California (ca. 23°N). The bulk of the observations were made in
the Manx Shearwater flocks off the Manzanilla-Acapulco area on 5 June. In
this area light-phase birds outnumbered dark-phase (5 to 1). Birds were
seen as far south as Panama where a light-phase bird was recorded.
Pale-footed Shearwater
Total Observations - 81
A flock of ca. 80 birds was following 20 + whales off the coast of
El Salvador on 9 June. Another single bird, thought to be this species,
was seen off Panama on the 11th.