I first looked at chimpanzees in 1972 at the Delta Regional Primate Research Center in Covington, Louisiana. Caroline Tutin and I had been sent there by David Hamburg and Stanford University to make ourselves useful while waiting for research clearance from Tanzania. As soon as permission was granted, we were to begin research in the Gombe National Park, under the direction of Jane Goodall. Meanwhile, at Delta we inherited from Emil Menzel two resources of great importance: a one-acre enclosure with seven chimpanzees and the patient guidance of Pal Midgett. As we stood amid the loblolly pines on that gloriously sunny January day and listened to the greeting hoots of Gigi and Co., it was the start of something good.

Nineteen years later, I have made 13 trips to Africa to study wild chimpanzees, lasting from 1 to 8 months and totalling over 4 years in the field. Five of these trips were to Tanzania, to work either at Gombe (1972, 1973, 1992) or Mahale (1974) or both (1982). Five (1976–1979) were to Senegal, to work at Mt. Assirik in the Pare National du Niokolo-Koba. Three were to Gabon, first to Belinga (1981), then to the Lopé Reserve (1985, 1990).

Many articles, chapters, notes, reviews, etc., have appeared since 1972, reporting the results of our studies, but until now no synthesis has been attempted. This volume aims to tie together a varied set of findings on tool-use and related activities. Of course, this is only a fraction of the field-work that has been done, but it is a start.