Associate professor at Leiden University since 1990; guest professor at Antwerp University since 2009. Member of the African Lion Working Group, member of the IUCN Cat specialist group, the Sirenia specialist group and the Canine specialist group and of the Steering Committee of the IUCN Species Survival Commission. Former Chair of the Netherlands Committee for IUCN (1990-2000), Co-Chair 2000-2003, Regional Councillor for West Europe (2008-2012). Member of the Netherlands CITES Commission, Chair of the Van Tienhoven Foundation and member of an Advisory Group to the Dutch Ministry. Active in the development of an action plan for lions in W and C Africa and involved in the harmonization of regional Red Lists. Initiated several National Conservation Strategies for threatened species and Red Listing in Europe.