Hot spot teeming with life

The island of Madagascar separated from Africa about 160 million years ago and from the Indian subcontinent some 80 million years ago. This isolation allowed a unique flora and fauna to evolve. It is home to 54 species of lemurs, a huge variety of prehistoric-looking chameleons, traveller's palms and dry forests of unusual spiny plants. It was home to herds of small hippopotamuses, lumbering giant tortoises, the baboon-sized archaeolemur and the huge elephant bird ( Aepyornis maximus ) that was up to 4m tall, weighed more than 400kg, and laid eggs 150 times larger than those of hens.

Many of the organisms of Madagascar are endemic to the island or occur only elsewhere on the nearby Comoros islands. Some 85 per cent of plant species, all 39 species of scorpions, 99 per cent of amphibians and 314 of the 346 species of reptiles are endemic to the island. In terms of biology and evolution, Madagascar is one of the most exciting places on earth. The island is ranked as one of the top five highest-priority hot spots of biodiversity, but many species are endangered. Unfortunately, a recurrent theme throughout this book is habitat destruction and species loss. It is, therefore, vitally important to bring together all the scientific information available about this island hot spot, so this comprehensive compendium is a most useful and welcome addition to the literature about Madagascar.

The book opens with a chapter on the history of scientific exploration of the fauna. This takes us from the 1658 publication of Etienne de Flacourt's Histoire de la Grande Isle Madagascar up to the recent training of Malagasy scientists. This has borne fruit as more than 60 of the almost 300 contributors to this volume are Malagasy. Much more than natural history is covered, since the chapter on geology and soil covers the abiotic forces that have moulded the biological patterns of the islands. Knowledge of this long geological history is essential to an understanding of the natural history, and this is followed by a chapter on the fascinating prehistoric ecosystem.

Chapter four covers forest ecology and chapter five human ecology.

Interestingly, humans have occupied the island for less than 2,000 years, and came from both Malaysia and Africa. This led to the rapid extinction of some of the most notable animals such as the elephant bird. Each chapter is divided into many sections by specialists on the subject, adding to the authority of this book. Chapter six is on the marine and coastal ecosystems, which are a vital part of the Malagasy ecosystem. It is sad to read of the effect of overfishing by industrial fisheries of the European Union, but good to learn that some marine reserves are being established.

The next eight chapters focus on specific groups of organisms: plants, invertebrates, insects, fish, amphibians, reptiles, birds and mammals. Each opens with a general introduction to the group and is followed by sections on the ecology and systematics. For example, the chapter on plants is divided into 46 sections, some on important families with other shorter entries covering plants of special interest. One of these is about the majakabetany ( Baudouinia rouxevillei ) - "the great king of the earth" that was formerly reserved for the Masikoro kings, who used it for sceptres. Now it is much sought after to ward off witches and evil spirits.

The plants covered vary from freshwater diatoms to the 170 species of palms. In the latter group, all but five species are endemic. There are 47 species of the coffee genus Coffea , which is about the same number as in Africa. One of the most diverse families is the leguminosae, with 573 native species, of which 459 are endemic. In addition there are 94 introduced species. Introduced and invasive species are a recurrent theme in the book. They include such varied organisms as the water hyacinth, reptiles and amphibians, rats, mice, the Asian musk shrew and guinea pigs, as well as some of the ticks and lice they bear. A section on the well-known traveller's palm ( Ravenala ) - which is not really a palm - shows that there are many variants recognised by local people both in natural and anthropogenic habitats.

Among the many groups of invertebrates covered are snails, spiders, ticks, shrimps, springtails, fleas, beetles, butterflies and moths. There are 2,831 known species of moths and 1,000 of ants. Another repeated theme is the number of organisms still to be described, especially of invertebrates, but this is mentioned for fish and amphibians as well. Some 28 of the 75 known species of snake were named and described as new in the past two decades of the 20th century. While many organisms remain to be described, others are being lost through habitat destruction.

Several chapters, such as the ones on amphibians and birds, refer to the severe effects of forest fragmentation on many groups of organisms. There are 283 species of birds in Madagascar, of which 209 breed regularly and 51 per cent are endemic. This is a high percentage for such a fragile group of animals. The bird chapter naturally has a good section on fossil birds and recent extinctions such as the elephant bird. I was glad to find a section on the couas, one of the most characteristic groups of birds in Madagascar.

I will never forget seeing the acrobatic manoeuvres of the blue coua.

But it is mammals for which Madagascar is particularly famous, especially lemurs, tenrecs and the nocturnal aye-aye. Such topics as the phylogeny of tenrecs and the food plants of lemurs are included. Each type of lemur has a section - dwarf, fat-tailed, mouse, bamboo and woolly, to name a few.

Some species merit individual sections, such as the ring-tailed lemur with its raccoon-like face mask and black-and-white ringed tail, and the indri.

I well remember the haunting call of the indri in the forests of northern Madagascar. The song is a mixture of a roar and wailing, beginning on a high note and becoming progressively lower. A taboo somewhat protects this species, owing to its reputed resemblance to the sacred ancestors of the Malagasy. It is the only lemur that lacks a long tail. Madagascar also boasts many other mammals - bats, bush pigs, mongoose, voles and tufted-tailed rats among them.

Most of the chapters on organisms have sections or comments about the need for, or lack of, conservation of the different groups. The final chapter addresses conservation and brings this theme together well.

Although only about 18 per cent of primary vegetation remains in Madagascar, there are 46 legally protected areas at 44 sites. The first of these, covering 5,700km2, was established as long ago as 19. Details of some reserves are presented together with data on ecosystem restoration. One section is on the re-introduction of captive-bred black-and-white ruffed lemurs. This project, which began in 1997, has had limited success, partly due to the predation by fosas ( Cryptoprocta ferox ), a badger-like animal. But a few individual lemurs have managed to survive and adapt. The conclusion from the conservation chapter is that much still needs to be done to ensure the protection of the plants and animals of Madagascar.

Each chapter is followed by extensive bibliographies - for example, the one on insects has a 29-page list of references. These will be very useful for researchers on Madagascar. There are also more than 100 pages of indices to scientific names, localities and subjects. Editor Steven Goodman has made a major contribution by writing many sections in the chapters on birds and mammals as well as translating many of the contributions of Malagasy authors and others from French to English. Throughout the book there is a large number of checklists of different organisms, distribution maps, diagrams and photographs. It is enhanced by beautiful photographs taken by Harald Schutz.

This weighty book of more than 1,700 pages is not a volume to carry around in the field, but it is essential reading before departing for any scientific work or nature travel to Madagascar. It is a most remarkable and thorough work and shows how much new research has been carried out in Madagascar in recent years. My hope is that it will further stimulate efforts to conserve the country's unique biological heritage.

Sir Ghillean Prance was formerly director, Royal Botanic Gardens, Kew, and is now scientific director, Eden Project. He is a tropical botanist who has carried out extensive research in the rainforests of the world.