Changes in range use of Geoffroy's tamarins (Saguinus geoffroyi) associated with habituation to observers.

Habituation of nonhuman primates to observer presence is a necessary and often arduous prologue to collection of data on individuals. Subjects are habituated so their behavior will be as close as is possible to their behavior if the observer were not present [1]. In an initial field study conducted on a new study group, habituation may account for a major proportion of the observers’ time [2–5]. Only recently has much attention been given to the actual habituation process [1, 4, 6–10]. The scant attention paid to habituation is somewhat surprising, since its study is more than study of methodological detal: it is an area of traditional importance in ethology and psychology [11]. Field studies of habituation add ecological relevance to this area of learning [12]. Popular accounts [3, 5] and quantitative analyses [4, 6] indicate that the first several months of habituation are often associated with a substantial reduction of flight distance. Studies conducted on groups that have been observed at close distance for years indicate that habituation may continue at a slower pace following the rapid early stage [1, 13]. Synthesis of the literature suggests that habituation is a continuous process with an initial rapid reduction of flight distance followed by a decelerating rate of change that may continue for more than a decade. This study was conducted to increase understanding of the initial stages of habituation and further develop methods for the study of these early stages. Received: December 3, 1996 Accepted: January 3, 1997