2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



making possible the accumulation of seabird observations by scientific 

 personnel aboard oceanographic research vessels that are systemati- 

 cally transecting the entire Indian Ocean. Some of the resulting 

 information has already been published (Bailey, 1964, 1965, 1966; 

 Pocklington, 1965; Pocklington and Risebrough, 1964; Rand, 1962, 

 1963). The present report is based on observations and collections 

 made by the author during IIOE cruise 5 of the r/v Anton Bruun 

 from January through April 1964 and also during a voyage of the 

 commercial vessel s.s. Kampala in May 1964. 



The cruise tracks of these two voyages are outlined in figure 1 and 

 the details of the itineraries are included in table 1. Cruise 5 of the 

 Anton Bruun originated and terminated in Bombay, India, on Jan. 26 

 and May 4, 1964, respectively and consisted of a direct transit across 

 the Arabian Sea from Bombay to the Gulf of Aden followed by a 

 north-south transect of the western Indian Ocean on longitude 55° E 

 and a south-north transect on longitude 75° E. A direct run from 

 Mauritius to 40° S, 75° E, connected the two transects. The passage 

 from Bombay to the Seychelles from May 17 to June 2, 1964, was a 

 scheduled run of the Kampala (British-India Lines) and included 

 stops at Karachi, Mombasa, and Zanzibar. 



At each station on the Anton Bruuri's itinerary, I maintained a 

 2-3-hour standardized watch for seabirds from the bridge of the 

 ship. During this period the ship was essentially stationary. In 

 the evening, while in transit to the next day's station at an average 

 speed of 10-12 knots, I counted seabirds again for an hour before 

 dusk. Records also were kept of all birds sighted between watch 

 periods; when I was not on deck, I was alerted to the presence of 

 seabirds by the officers on watch. 



The main difference influencing the observations made from the 

 Kampala was the continuous movement of the ship (15 knots) and the 

 fact that I could only watch from one side of the ship at a time, nar- 

 rowing the radius of observation from 360° to slightly less than 180°. 



Some seabirds were collected from a small rubber "Zodiac" boat in 

 subantarctic waters and during our brief visits to the Seychelles, 

 Mauritius, Amsterdam, and St. Paul Islands. Although the latter 

 two islands will be included in this report, only those birds seen at 

 sea in the vicinity of the Seychelles and Mascarene Islands are dis- 

 cussed here, as studies on these islands were continued from June to 

 November 1964 and will be published elsewhere. 



In the course of this work I have kept detailed notes and descrip- 

 tions of all unfamiliar seabirds and have found the following references 

 especially useful for identification: "Birds of the Ocean" (Alexander, 

 1954), "The Petrels of the Indian Ocean" (Bourne, 1960), "A Pre- 

 liminary Field Guide to Birds of the Indian Ocean" (Watson, Zusi, and 



