Birds to watch 2. The world list of threatened birds. By N. J. Collar, M. J. Crosby & A. J. Stattersfield. BirdLife International, Cambridge. BirdLife Conservation Series, No. 4. 1994. 407 pp. ISBN 0 946888 30 2. Price: £20.50.
economic interests; however, in the case of Ascension Island, where the feral cats prevent seabirds from nesting on the main island, the solution is straightforward if sufficient resources can be made available to do the work.
Although this is a replacement volume of a book published six years ago, it represents an entirely new evaluation of the world's threatened bird species using new criteria and a more standardised presentation of the text. A total of 1111 bird species (11% of the world's bird fauna) have been identified as threatened with a further 11 allocated to the category of Conservationdependent, 66 to Data Deficient, and 875 to Nearthreatened. By allocating species to the categories Critical (50% chance of extinction in 5 years), Endangered (20% chance of extinction in 20 years) and Vulnerable (10% chance of extinction in 100 years), it is estimated that 100 species will disappear in 5-10 years, 200 in the next 20 years, and 400 in 100 years. An analysis of the habitats of threatened species shows that the four most affected are forests (65%), scrub (9.3%), wetlands (8.8%) and grassland (6.3%). BirdLife International has already identified Endemic Bird Areas, key forests for threatened Afrotropical birds, key areas for threatened Neotropical birds, and Important Bird Areas in both Europe and the Middle East, and this very thoroughly compiled volume continues this excellent service to wildlife conservation.
Seabirds on islands. Threats, case studies and action plans. Edited by D. N. Nettleship, J. Burger & M. Gochfeld. BirdLife International, Cambridge. BirdLife Conservation Series, No. 1. 1994, 318 ISBN 0 946888 23 X. Price: £23.75. Birds on islands have suffered more than man's activities than perhaps elsewhere in terrestrial environments. Seabirds, however, are generally thought to be somewhat less vulnerable as they come ashore only to nest. This volume, which reports on a workship organised by the Seabird Specialist Group of BirdLife International, shows that there are many causes for concern because of population growth making greater demands on coastal areas, the spread of urban and industrial development and lack of interest in wildlife conservation in many countries. The 21 contributions are arranged under four headings--threats to seabirds; major seabird problems; action plans, progress and solutions; conclusions and actions. Although introduced predators have ravaged seabird populations for many years the contributors to this volume seem to demonstrate that direct action by man either by exploitation or by destroying the habitat or food supply by overfishing is an even greater problem. In many instances it is difficult to take effective action to safeguard populations because of the power of
Global biodiversity assessment. Edited by Vernon H. Heywood. Cambridge University Press for UNEP, Cambridge. 1995. 1140 pp. ISBN 0 521 56403 4 (hbk), 0 521 56481 6 (pbk). Price: £80.00, US$110.00 (hbk), £29.95, US$44.95 (pbk). The idea for this very comprehensive review was made in May 1993 by the Scientific Advisory Panel of the Global Environment Facility to the United Nations Environment Programme (UNEP). About 1,500 scientific experts from all over the world contributed to its preparation, making it the most complete and authoritative statement of its kind which has been made on the subject of biodiversity and its importance to the world's natural resources. The report contains the most accurate estimate yet made of the total number of species on the earth, between 13 and 14 million, of which only 13% have been scientifically described. UNEP concludes that we still have only a very incomplete understanding of the distribution biology and genetic diversity of the planet's natural life. We are warned that the quickening rate of extinctions due to man's activities means that we are losing genes, habitats and ecosystems more rapidly than previously thought. In the early to mid-1980s humid tropical forests were losing nearly 10 million hectares annually. Dry tropical forest has lost even more. On the Pacific coast of Central America the forest once covered 500,000 km 2 but only 2% is left. A similar story is found for wetlands, mangrove swamps and the Atlantic forest of Brazil. Some species are known to be important for the proper functioning of ecosystems; for example, mycorrhizal fungi regulating uptake of soil phosphorus and water absorption by plants. The loss of such 'keystone' species would greatly reduce the productive capacity of an ecosystem. Of the 240,000 known flowering plants about 25% have edible properties and yet only about 100 provide 90% of human food supplies. The report's main findings are that humans are the main cause of the increasing loss of biodiversity, which is the natural biological capital of the earth. The wasteful exploitation of this resource on which the existence of us all ultimately depends must be halted. We must realise that genetic variation within species is the basis for evolution, for the adaptation of wild populations to local environmental conditions and for the development of animal breeds and cultivated crop varieties that have yielded significant benefits for humanity. This variation is the origin of modern agriculture, forestry, fisheries and new biotechnologies.