The Indian Ocean and its oceanic islands were long neglected by ornithologists, though the writings of early travellers contain a certain amount of incidental information. The first systematic observations on the seabirds were made by Gould and Hutton in particular on voyages from Europe to Australia via the Cape of Good Hope, and on the landbirds by Edward Newton and his friends and correspondents in the last century, and the first observation on birds during the course of larger expeditions during the German ' Valdivia' expedition in 1899, and the Percy Sladen Trust expedition of 1905. Thereafter with only minor exceptions such as the observation by H. G. Alexander of the occurrence of a bird concentration off the south coast of Arabia there was little further work until after the last war.

In the early 1950s the British Royal Naval Bird-watching Society then instituted a sea report scheme, in which its members made regular observations of birds encountered on special forms. These rapidly became popular in the Navy, and soon in the Merchant Marine as well, so that by the end of this decade some scores of reports were available from most parts of the ocean, indicating a rich marine avifaima. When the International Indian Ocean Expedition was being planned the British Ornithologists' Union therefore agreed with the National Institute for Oceanography to send an ornithologist to participate in the British contribution on board RRS Discovery III, and selected Roger Bailey for the post, while several other nations also subsequently arranged ornithological contributions as well.

The main results of this programme of work are a fair understanding of pelagic seabird distribution in the area (poorest in the Bay of Bengal) and identification of areas with an increased bird density—along coastlines and around islands, near the convergences or fronts around 35°S and near the equator when the counter-current is present during the northerly monsoons, in the cool current areas off South Africa and especially western Australia, and where the surface water drifts offshore along the south coast of Arabia, the East Indies/and north-east Australia during the southerly monsoons. It is notable that when the counter-current disappears at this time a number of southern seabirds penetrate further north than is usual in other oceans to feed in the upwelling areas off the continental coasts. The investigation of the oceanic islands at the same time has revived interest in their remarkable endemic birds and drawn attention to the urgent need for further conservation.