Reviews Flamingos
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Reviews flamingos. Edited by Janet Kear and Nicole Duplaix-Hall. T, & A. D. Poyser, Berkhamsted, 1975. 246 pages; seven colour plates; 48 black-and-white plates; numerous draw ings, maps and diagrams, £8.00. In July 1973 an international gathering of flamingo specialists met at SUmbridge, Gloucestershire. The results are now available to a wide audience through this book of 3g chapters derived from papers given there by 30 authors representing all continents where flamingos occur. This clear presentation of data on their status has been eagerly awaited by conservationists and ornithologists interested in this unique group of birds, one of the oldest alive today. The ecological requirements of flamingos are narrow, which has led to breeding and migratory habits of seemingly erratic character, not yet fully understood. The Camargue Greater Flamingos, which are more intensely studied than any other population, are discussed by A. R. Johnson. The majority of these move south-west from Camargue to Andalusia and north-western Africa. The delta of Guadalquivir is probably the main winter area; over one third of all recoveries of ringed birds occurs there, perhaps because flamingos are considered game in Spain. Other Camargue flamingos migrate to Portugal, Sardinia, Morocco, Algeria and Tunisia, with recoveries also from Turkey, Libya, Mauritania and Senegal. In Spain breeding is infrequent and often unsuccessful, which emphasises the importance of preserving the Camargue colony, the only permanent one in Europe. (The Russian colony at the north-eastern shore of the Caspian Sea disappeared after 1946 as a result of the man-made hydrographic changes in this area.) Data on this species as a breeding bird in northern Africa are rather scarce, but colonies have been recorded in Tunisia, Morocco and Mauritania. Leslie Brown gives an excellent chapter on the status, movements, continued... 182 Reviews 183 breeding success, population dynamics and conservation necessities of the Greater and Lesser Flamingos in eastern Africa. All his available figures suggest that both species must be long-lived. A new phenomenon which greatly affects the productivity of the Greater Flamingo at Lake Elmenteita in Kenya is the predation by Marabou Storks during the last years. Both Brown and H. H. Berry (in his chapter on South West Africa) assume that the East African popu lation of flamingos is separated from the Etosha Pan-Makarikari Pans population in South West Africa and Botswana. However, there is a regular passage of Greater Flamingos in both Rhodesia and Malawi, so there might be connections between the two populations. On the Etosha Pan a remarkable walking migration of Lesser Flamingos was observed in 1971, released by receding water. Four colonies of chicks trekked 80 km in small groups, averaging three km a day. Although a few adults accompanied the walking chicks, the parents probably found and fed their offspring during the entire migration, flying return journeys of up to 100 km to obtain food. This extraordinary evacuation operation was successful. Similar feeding movements are described by Jan Rooth for the Caribbean Flamingo on Bonaire. Here the birds severely diminished the local food supply, but adults flew to Venezuela, a distance of 140 km, returning after about twelve hours to feed their young. They also turned to another food source near the colony, eating mud, which is rich in organic material. Recent developments on Bonaire have changed the food situation considerably, eliminating the staple food, Brine-flies Ephydra cinerea and Brine-shrimps Artemia salina, but the flamingos have been able to switch completely to the molluscs Cerithium and Cerithidea. Rooth also describes how commercial exploitation on flamingo sites can be managed in a way acceptable to the birds. M. P. Kahl summarises the distribution and numbers of all species and subspecies of flamingos. The estimated total populations are: Caribbean Flamingo 60,500; Greater Flamingo 790,000; Chilean Flamingo 500,000; Lesser Flamingo 6,000,000; Andean Flamingo 150,000; and James's Flamingo 21,700. Other chapters of the book deal with flamingos in captivity (Sir Peter Scott believes that within ten years zoos should be breeding all the flamingos they need), ethology and physiology. Flamingos are seriously threatened only by man. Their speciali sation makes them vulnerable to human depredations and dis turbances, particularly in the Andes and in salt and soda exploita tion areas of various parts of the world. This book, with its wealth of data, is a valuable examination of their status and of what can be done to maintain their numbers at present levels. KAI CURRY-LINDAHL 184 Reviews Pine Crossbills. By Desmond Nethersole-Thompson. T. & A. D. Poyser, Berkhamsted, 1975. 256 pages; one colour and 24 black-and-white photographs; numerous tables and figures. £5.00. Desmond Nethersole-Thompson recounts his early days with Crossbills in East Anglia and his first meetings with Scottish Cross bills in Strathspey, where he was struck by the different calls of the northern birds. Thus started 40 years of careful study, and in this monograph he describes the life history and behaviour of the Cross bills of the Scottish pine forests. These interesting birds live in a fine environment where remnants of the old Caledonian forests nestle in the central and eastern glens of the Highlands. As usual, the author has researched his subject fully; his story starts with reference to the bird's place in history and legend, and its fascinating content is a forerunner to a thoroughly interesting book. One of the main topics of the book is the difficult taxonomic problem of whether to regard the Scottish Crossbill as a distinct species, a subspecies of the Common Crossbill Loxia curvirostra or a subspecies of the Parrot Crossbill L. pytyopsittacus. There is a discussion of the relationship between various crossbills and their main food trees, the larger-billed birds feeding on the harder cones of pine trees. Frequent comparison is made between Scottish Crossbill activities and those of Common, Parrot and Two-barred Crossbills. Nethersole- Thompson decides to re-designate the Scottish Crossbill as L.pinicola pinicola; in a special appendix, A. G. Knox comes down in favour of an earlier designation as L. scotica while Dr I. Newton regards it as a subspecies of L. curvirostra. The reader can make his own choice. There are chapters on egg-collectors, haunts and neighbours, flocks, courtship, territory, aspects of breeding biology, voice, food, competitors and predators. Much of this information is personal observation backed by correspondence with other crossbill-watchers; there are many original data. The final chapters, on distribution, numbers, movements, and speculations, reveal that the author estimates the Scottish Crossbill population as low as 100 pairs in the 1960's and 320 pairs in the 1970's; he stresses the difficulties of estimating the population and the erratic nature of the bird but suggests a stock of about 1,500 adult birds in recent years, its future looking reasonably secure. The book is rounded off by much extra information in the form of five appendices and 17 tables; I found the nest diaries rather difficult reading and my only criticism of the book is occasional repetition. The photographs are good while the line drawings are attractive; I liked the nice bright cover. In my view the book is a superb addition to the author's previous three monographs on Greenshank, Snow Bunting and Dotterel. All four should be taken Reviews 185 as a whole, and as such reveal a fine story about four special Scottish birds, the superb Highland area and one of Scotland's most notable ornithologists. ROY H. DENNIS To Save a Bird in Peril. By David R. Zimmerman. Coward, McCann and Geoghan Inc., New York, 1975. 286 pages; illustrations and maps by Nancy Lou Nahan. §9.95. This is one of the most thought-provoking books I have read about tampering with nature, for which a new name has been coined: 'clinical ornithology'. In a generally readable and racy style, Zimmerman reports in detail on what has been done to save those species whose numbers have dwindled so low that they are thought to be in danger of extinction. These species live mostly in the New World and include, among others, the Californian Condor, Whoop ing Crane, Neja6, Osprey, Peregrine, Cahow and Kirtland Warbler. He outlines the techniques used to resuscitate species which have been hard hit by some special beastliness of man—poison or pollu tion—or which have been unable to adapt to physical changes in the environment. Indeed, nearly all the schemes discussed by Zimmerman fall into one or other of these two categories. He reports on the arguments, the criticisms, the bitterness, perhaps the 'sour grapes' when the schemes progressed slowly or went awry, as well as on the happiness and the successes. Inevitably a number of questions spring to mind. For instance, should we interfere with evolution ? If a species cannot adapt to changes in the physical environment should one endeavour to keep it alive artificially ? Sad as it undoubtedly is, the vultures of southern Europe are dwindling away because of 'cleaner' farming methods; can we really believe that 'vulture restaurants' are going to prevent their retreat? Is it really possible to maintain a viable population of vultures for ever? Artificial feeding points, whether in gardens or on the Spanish plains, are fun and may save a few individuals, but they rarely save populations. Is spending thousands, if not hundreds of thousands, of dollars on rescuing some obsolete species really wise use of conservation resources? At some stage we will have to switch off the 'life-support system'. Similarly, he also makes a number of questionable statements about the value of some of these techniques for conservation.