Part I. General Introduction

Abstract

Tristan da Cunha and the three neighbouring islands of Inaccessible, Nightingale and Gough support a unique flora and fauna, poor in numbers of species but rich in endemics. Many of the endemics occur throughout the archipelago while others, some of great peculiarity, such as the flightless birds, are confined to single islands. Knowledge of the environmental conditions which have prevailed during the evolution of such a biota is very much to be desired. It is in this respect that examination of the damage caused by the volcanic eruption which began on Tristan da Gunha during October 1961 is most important. There are over thirty secondary eruptive centres which form very fresh, prominent features of the topography of Tristan. It is highly probable that the biota has suffered from volcanic activity many times in ways similar to, if not more severe than, those which occurred during 1961 and 1962. Soon after the eruption started, the Royal Society began to organize an expedition to study the new volcano, to make a geological survey of the Tristan archipelago and to investigate the effects of the eruption on the vegetation and fauna. Details of the history of the Expedition and the geological results are given by Baker, Gass, Harris & Le Maitre (1964). The inclusion of a botanist (J. H. Dickson) and a zoologist (D. E. Baird) was made possible by the generous financial support given to the project by the Trustees of the World Wildlife Fund.