Book review: Avian history is written by the winners

Abstract

news and update book review Avian history is written by the winners Avian survivors: The history and biogeography of Palearctic birds, by Clive Finlayson, 2011, T & AD Poyser Ltd., 304 pp. £50 (Hardback) ISBN: 9780713688658; http://www.acblack.com/naturalhistory/ This is a difficult book to review fairly, because it is not a book to read through, nor is its intention easily discerned. It is a profound and deeply detailed compilation, assessing the climatic, historical and biogeographical attributes of the bird fauna of the Western Palaearctic. Its intention is to understand how this particular constellation of species survived through the climatic vicissitudes of the Tertiary Period, and especially the last 2 million years of the Pleistocene climatic fluctuations, to be combined as the extant fauna. Finlayson was inspired by the remarkably diverse faunas that appear in the caves of Gibraltar, at the extreme southern tip of the Western Palaearctic. At different times these included northern species such as Great Auk and Velvet Scoter, at others southern species such as Lammergeier and Crag Martin. Those that still occur in the Palaearctic are the survivors of his title. He starts with a short outline of the climatic, geographical and ecological changes that affected the region during the Tertiary, as Africa and India shifted north to collide with Europe and Asia, so closing the Mediterranean, and causing the uplift of the mountain ranges across central Europe and Asia that changed the climate, especially the strength and direction of rain-bearing winds. Grasses evolved in this period, and grasslands, replacing tropical forests, became more widespread. His analysis of the times of origin of bird genera that, at present, include migratory species, especially Trans-Saharan migrants, suggests that many of them evolved in the Miocene, as the grasslands appeared. Popular, perhaps superficial, opinion has assumed that the glacial-interglacial cycles of the Pleistocene prompted the evolution of the migratory habit, but this analysis strongly suggests that it was already well established. The majority of the book is a detailed examination of each family, genus and species that is currently represented in the Palaearctic. It assesses their climatic limits, habitat requirements and likely history. Much modern work on genetic phylogeny is used to assess the zoogeographic origins of such taxa, when they migrated into the Palaearctic, and how their climatic requirements have persisted, along with the taxa themselves. Each is assigned to its climatic and latitudinal tolerance ranges, and to its migratory group (sedentary, partial migrant, Trans-Saharan migrant). For instance, Finlayson interprets the history of the Corvidae as probably evolving in Australia, and migrating into the tropical forests of Southeast Asia, where a great diversity of basal genera still occur; but one, the Choughs (Pyrrhocorax) migrated out along the great mountain chain right across Asia and Europe in the Miocene, as mountain uplift created their drier upland habitat. However, most corvids remained essentially forest species, and migrated west along the forest belts south (mostly deciduous) or north (mostly coniferous) of the mountains. Corvids reside mostly in more humid climatic zones, and few show much migratory behaviour. Fossil corvids are represented in Europe by Middle Miocene times; two modern genera are present by the Early Pliocene (Pyrrhocorax, Pica, two more by Middle Pliocene (Garrulus, Nucifraga) and all by Early Pleistocene. Sometimes the detailed evidence on which such histories are based is clearly indicated. The fossil record is largely quoting the compilation by Mlikovský (2002), and the phylogenetic references are well cited. However, much of the story is informed speculation, of probable histories and probable spreads, based upon known climatic and geographical changes, and the known broad ecological requirements of the taxa. Given the number of taxa involved, this amounts to quite a lot of speculation accumulated over the book as a whole. This is not to suggest that it is wrong, nor does it deny its value. A lot of diverse information frontiers of biogeography 4.1, 2012 — © 2012 the authors; journal compilation © 2012 The International Biogeography Society