Animal sexology investigations in Belgium and The Netherlands can boast two research traditions. The ethological tradition is concemed with observations on mating strategies under natural or seminatural conditions. This approach is followed by the University of Utrecht, and observations are taking place at Burgers Zoo and Safari Park in a variety of species. The second research tradition is directed at the experimental analysis of sexual behaviour under controlled laboratory conditions. The research efforts concentrate on brain mechanisms involved in hormonal control of sexual behaviour. This approach is followed by three research groups at the universities of LiŽge, Amsterdam and Rotterdam. These investigations concern the analysis of copulatory behaviour in the quail (LiŽge) and in the laboratory rat (Amsterdam and Rotterdam) and the stumptailed monkey (Rotterdam).