AN ANALYSIS OF THE PELAGIC BIRD FAUNAS OF THE 

 INDO-PACIFIC OCEANS 



By D. L. Serventy 

 Wildlife Survey Section, CSIRO, Pei-th, Western Australia 



1. Introduction 



An analysis of the pelagic sea-bird faunas of any one of the three 

 great oceans— the Atlantic, the Pacific and the Indian— cannot be dis- 

 sociated from similar studies of the other two, and so though this es- 

 say is primarily concerned with the Indo-Pacific basins, the bird fauna 

 of the Atlantic is constantly referred to. The method of inquiry pur- 

 sued is that of a study of faunas and not faunal regions, and so necessi- 

 tates a consideration of distribution patterns in the neighboring oceans. 



This paper is a re-statement and an interpretation of known tax- 

 onomic and zoo-geographical facts and depends on the fulness and ac- 

 curacy of these basic data. Where they were scanty or lacking, the 

 author has made some bold speculations which may or may not be 

 upheld by later investigation. 



At this stage of knowledge of the subject, it seems debatable whether 

 one is justified in giving more than a sketchy outline of the events 

 which may have taken place. More detailed treatment of a subject, 

 in which lack of adequate data forbids much precision, is bound to 

 arouse unfortunate reactions. Workers outside of our particular field 

 are not slow to point out the unsatisfying nature of such hypotheses, 

 when they race too far ahead of the basic factual studies on which 

 they depend. Thus in a review of a w^ork on the fauna of Britain, 

 T.T. Macan (1953, p. 172) likens the various components of faunas 

 mixed up by the retreats and advances of the Ice Age as "an omelette, 

 attempts to unscramble which are a source of continual fascination to- 

 day. To a ringside observer, such as the reviewer, . . . the number of 

 unknown factors seems to justify a sceptical attitude towards all attempts 

 at unscrambling." Ultra-caution such as this might deter investigators 

 from attempting to unscramble any type of biological omelette, and 

 I am making bold to attempt something of the sort for a kindred prob- 

 lem in the Indo-Pacific. The unscrambling attempt is offered as a ten- 

 tative proposal to other unscramblers for their comments and assistance. 



The preparation of the paper has more than ever impressed on 

 the author the indebtedness of all students of pelagic birds to the work 



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