He left WWF in 1979 to work as a freelance writer and photographer concentrating on wildlife. In 1983, because of his extensive knowledge of the tiger, he was invited by the Species Survival Commission of the World Conservation (IUCN) to become Chairman of the Cat Specialist Group. Under his leadership until 2000, the group grew to nearly 200 of the world's leading scientists and wildlife managers, who provide advice to governments and international organisations on conservation of wild cats. As Chairman he travelled to many parts of the world - much of Asia, Africa and North and South America.
In recognition of his dedication he received The Peter Scott Award for Conservation Merit of the Species Survival Commission at the World Conservation Congress in Amman in 2000,. He is an Officer of the Order of the Golden Ark, established by HRH Prince Bernhard of the Netherlands to honour contributors to conservation.
Peter has written books on tigers and elephants, as well as a major reference work on all the wild cats. In collaboration with his wife, he produced a guide to the world's wild cats, Les Félins, which was published in French by Delachaux et Niestle, Lausann & Paris. An English edition will be published in the USA.