48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I50 



Measurements (from Murphy, Oceanic Birds S. Amer., 1936, p. 

 744). — Adult, sexes alike (from 10 specimens from the California 

 breeding grounds), wing 168-177, tail 80-86, culmen 15-16.5, tarsus 

 31-34 mm. 



Iris brown ; bill black ; inside of mouth and tongue yellow ; tarsus 

 and toes black. 



Regular visitor, off the Pacific coast. 



The black petrel breeds in the north around Baja California, at 

 Los Coronados and San Benito islands on the northwest coast, and 

 on islands in the northern third of Golfo de California. Bent (U. S. 

 Nat. Mus. Bull. 121, 1922, pp. 157, 158) records eggs from May 



30 to July 23, and young in early September. Available dates of 

 occurrence in Panamanian waters are as follows, arranged in order 

 of monthly occurrence (without regard to the year) : January 16 to 



31 (I960), February 25 (1957), March 14 (1944), March 21, 24 

 (1952), March 31 (1962), records by the writer; March 24 (1915), 

 specimen taken by Hallinan ; July 18, 19, 23, sight records by Robins 

 (Condor, 1958, p. 301) ; September 8, 9 (1924), specimens in British 

 Museum (Natural History) ; November (1956), sight records by 

 R. C. Murphy. Apparently the southward movement may start im- 

 mediately when the first young are on the wing. At the end of 

 March 1952, northward migration may have begun, as on the even- 

 ing of the 21st one flew into the open, strongly lighted dining room 

 of the hotel on Taboga Island. 



(Sight records of petrels in these waters on September 18, 1939, 

 by Fleming, Emu, 1950, p. 177, reported as Oceanodro'nta markhami, 

 may have been of this species.) 



In travel by launch in the Gulf of Panama, black petrels may be 

 noted flying just above the water, moving somewhat erratically from 

 side to side, but at the same time following a fairly direct course. 

 In most instances the view is a distant one since they do not follow 

 boats, and so are encountered only by chance. While they fly low they 

 move less in the troughs of the waves than the fluttering petrel and 

 also have a more direct line of flight. However, they travel with fair 

 rapidity and soon pass from sight. Usually they range well away 

 from land, though I have noted them within 8 kilometers of Balboa. 

 Though most common in the Gulf of Panama they are found also to 

 the south off Darien. 



Order PELECANIFORMES 



Family PHAETHONTIDAE : Tropicbirds ; Aves del Tropico 



The three species of this family have an appropriate English name 

 as they range tropical seas on either side of the Equator around the 



