July, 1905 | BIRDS FROM THE WEST COAST OF LOWER CALIFORNIA 
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lupe; but after May 1st the least, black, Socorro, and Kaeding petrels appeared, 
becoming more numerous during June and apparently passing north to the breed- 
ing grounds from the regions south of Socorro Island. Mr. Townsend secured but 
one specimen of Ocea?iodro»ia socorroensis at Socorro Island and saw very few 
March 9th," so that it is probable that the bulk of the birds were still to the south- 
ward at that date. It is interesting to note in this connection that so far as we 
were able to ascertain, there are no sea birds nesting on Socorro Island at all, with 
the exception of the terns nesting on the outlying rocks. Mr. Townsend found 
burrows that he judged would be occupied later by petrels," but I am constrained 
to believe that these were the burrows of the land crabs, which swarm over the 
island. These crabs are so voracious and bold that it would hardly be possible for 
even a shearwater to withstand their attacks, and this is probably the reason why, 
although thousands of shearwaters nest on San Benedicte thirty miles away, none 
nest on Socorro, there being very few crabs on San Benedicte. 
Phaethon aethereus Linn. Red-billed Tropic Bird. Breeds sparingly on San 
Benedicte Island May and June; seen near Socorro, Clarion and Roca Partida 
Islands, at sea; seen off Magdalena Bay on June 6th. 
- Phaethon rubricaudus Bodd. Red-tailed Tropic Bird. Known in these waters 
from the single specimen taken by our party near Guadalupe Island on July 23rd. 
- Sula cyanops Sund. Blue-faced Booby. Common on San Benedicte and 
Clarion Islands, breeding; iresh eggs were taken as early as April 30th and as late 
as June 1st. This booby, as well as Sula brewsteri and Sula piscatrix websteri , is 
often seen fishing at Socorro Island, but as far as we could see none of the boobies 
nest on Socorro. 
Sula brewsteri Goss. Brewster Booby. Brewster booby breeds sparingly on 
San Benedicte Island, the eggs taken during May being partially incubated. 
Should Sula brewsteri ncsiotes Heller & Snodgrass prove tenable, these San Ben- 
edicte Island birds may be referable to the latter race. 
Sula piscatrix websteri Rothschild. Webster Booby. Webster booby is by 
far the most numerous of the three boobies nesting on the islands of this group. 
It nests abundantly on San Benedicte and on Clarion Islands, the nests on the for- 
mer island being placed on grass hummocks, etc., while on Clarion the majority 
of the nests are placed on the tops of the low tree ( Dodoncca viscosa L.) which 
grows in rather close thickets or groves on certain portions of the island. 
The eggs are laid during May. 
Phalacrocorax dilophus albociliatus Ridgw. Farallone Cormorant. Noted on 
Todos Santos, San Martin and San Geronimo Islands March 10th to 15th; reported 
as breeding commonly along this coast from San Diego to the Cape. 
Phalacrocorax penicillatus (Brandt). Brandt Cormorant. Todos Santos, San 
Martin, San Geronimo and Cerros Islands, March 10th to 31st; breeding range and 
abundance apparently about the same as that of the Farallone cormorant. 
Phalacrocorax pelagicus resplendens (Aud.). Baird Cormorant. Noted only 
on San Geronimo Island, where a few individuals were seen on March 15th. 
Pelecanus erythrorhynchos Gmel. American White Pelican. A small flock 
of these birds was seen on San Geronimo Island on March 15th. 
Pelecanus californicus Ridg. California Brown Pelican. Abundant on San 
Martin Island March 12th, where it is known to breed. 
Fregata aquila Linn. Man-o’-war Bird. The frigate bird breeds commonly 
on San Benedicte and Clarion Island, full grown young and fresh eggs (second 
a. Cf. Townsend, Birds from the Coasts of Western North America, etc Proc. U. S. Nat. Mus., XIII, 1890, 134-5. 
