National Geographic : 1938 Aug
WINGS OVER THE BOUNDING MAIN "MOTHER CAREY'S CHICKENS" SAILORS CALL THEM The BULWER'S PETREL (left center) frequents the eastern Atlantic and the western Pacific. Strictly Pacific species are the other somberly clad little mariners. To the right of the lovely pearl-gray FORK-TAILED PETREL (upper) hovers the BLACK PETREL, one of the few birds that migrate north after the breeding season. Water drips from the feet of the rising SoCORRO PETREL (lower right). Smallest of the all-dark species is the LEAST PETREL (left foreground), which half faces the pert AsHY PETREL.