Volume 19, number 4 of Western Birds, published 1988
Western Field Ornithologists and the California Bird Records Committee are again pleased to thank Bushnell Corporation for its continued support. Bushnell has again been generous in sponsoring the publication of this report, including the printing of color photographs.
On 17 August 1974, G. McCaskie, R. Unitt, J. L. Dunn, and J. Butler discovered and collected a small sandpiper near the mouth of the Alamo River at the south end of the Salton Sea, Imperial County (McCaskie 1975). They identified the bird as a Rufous-necked Sandpiper (Calidris ruficollis); the specimen is now number 38887 at the San Diego Natural History Museum.
The behavior of the Ferruginous Hawk (Buteo regalis) has not been studied extensively during the non-nesting season. Ferruginous Hawks are less social than most other hawks of the genus Buteo. They are not known to flock in migration (Brown and Amadon, 1968, Eagles, Hawks and Falcons of the World, McGraw-Hill, New York) and are rarely found in groups in winter.
In the only previous report of a communal winter roost of this species, Steenhof (1984, Wilson Bull. 96:137–138) described a South Dakota roost in cottonwoods (Populus deltoides) being used by one to six Ferruginous Hawks on 11 of 25 mornings during the winter of 1975–76. On nine of the mornings, the roost was shared with Bald Eagles (Haliaeetus leucocephalus).
On 23 April 1988, we observed a juvenile Masked Booby (Sula dactylatra) roosting on a small rock off the north end of Isla Coronado Sur, Baja California, Mexico. The Islas Los Coronados are situated 6 nautical miles (nm) off the west coast of northern Baja California, and 4 nm south of the United States/Mexico boundary.
We first noticed the bird at 12:50 as we cruised around the north end of the island. We slowly approached and observed it for 25 minutes at distances as close as 6 meters (photographs on file at the San Diego Natural History Museum). Throughout our observation, the bird seemed oblivious to our presence, despite several attempts to flush it by sounding our air horn.
