No fairy-tale end for toad

Frogs and toads have been around for more than 300 million years and occur in a bewildering variety of forms. In Britain we have only a few species, but many of us will be familiar with them and their remarkable, complex life cycles, with tadpoles that hatch from clumps or strings of jelly-like spawn before metamorphosing into miniatures of the adults. In Search of the Golden Frog is Marty Crump's journal of her life and work with frogs, toads and other amphibians and reptiles in Central and South America.

The book records her travels through the region over some 30 years, describing the highs and lows of her various field projects and the very personal dilemma of trying to juggle her ambitions as a scientist with the responsibilities of a young mother. As eloquently suggested by the title of one its chapters, "Expressing in the rain", the two are not incompatible.

Seasoned explorers of the tropics will sympathise with the trials and tribulations faced by Crump: almost daily exhaustion, oppressive heat and humidity, parasites, and frequent little reminders of just how unpredictable jungle life can be, such as grabbing hold of a branch to save yourself from stumbling only to find it is covered with spines that break off in the palm of your hand and leave you in pain for a week. We learn also of how she copes with probably the greatest danger of all - getting lost. But for all its hardships, the rainforest for Crump is clearly a magical and enchanting place.

Much of the book is devoted to the natural history of the author's subjects of study (some illustrated with colour and monochrome photographs), among them Darwin's frog, the males of which carry their developing brood in special throat pouches until the moment of "birth", and the poison-dart frogs, with their gaudy colour patterns and lethally toxic skin secretions. Fascinating and exquisite as these animals are, however, the reader is spared being over-bombarded with biology, digression at refreshing intervals being provided by way of accounts of local history, folklore, stunning landscapes and national customs.

Threaded through the book are references to a growing catastrophe that threatens to extirpate many species of frogs and toads. Over the past decade or so, these animals have been disappearing all over the world, with more than 200 species reported to be in decline and at least 20 presumed to be extinct. No single cause has been identified that can explain this alarming state of affairs, and a particularly disturbing observation is that many of those in trouble occur in areas protected from the usual blights of habitat destruction and pollution.

One species in particular, the golden toad of Costa Rica (not the creature alluded to in the book's title), has come to epitomise the phenomenon, and its spectacular demise was observed at first hand by the author herself. As recently as 1987, hundreds of these toads could be seen at the beginning of the rainy season congregated around their breeding pools high in the cloud forests of the Cordillera de Tilar n, but by 1989 only a single solitary male was recorded, the last apparent survivor.

As Crump solemnly concludes: "The next couple of decades will be busy ones for field herpetologists. We not only have the responsibility of documenting amphibian declines, we have the challenge of identifying the causes and then trying to reverse the situation."

Like-minded professionals will appreciate the author's attention to detail, but far from being a heavy read this is a lively, charmingly written book that will appeal to anyone with an appetite for natural history and exotic places.

Peter J. Stafford is research biologist, Natural History Museum, London.