Some nonhuman primates use tools to modify the behavior of other animals in social contexts. For example, during their proceptive periods, female bearded capuchins (Sapajus libidinosus) in two wild groups throw stones and push branches toward males, which may function to draw male attention to the females. To further clarify the social and communicative relevance of this behavior, we recorded all occurrences of object use in a captive group (one adult male and four females) at Brasília Zoo, during 963 h of observation. Additionally, we recorded the occurrence of typical proceptive behaviors and quantified behavioral changes of the male associated with throwing behavior. All females threw objects, such as stones and sticks, at the male (N = 205 events). One of the females also pounded objects near the male (N = 72). The two forms of object use were associated with female proceptivity. Male-directed throws increased the chances of the male changing his behavior, particularly by shifting his attention to the thrower, supporting the hypothesis that throwing at the male function as a communicative act. However, females also used aimed throwing in affiliative contexts (N = 2) and interactions with humans (N = 102) and other animals (N = 61). Thus, our results show that aimed throwing is a flexible behavior, elicited in multiple social contexts and for different purposes. Moreover, our study demonstrates that considering the effects of object use on the behavior of potential targets can help us to understand how primates use objects to mediate communication.

一些非人类的灵长类动物使用工具来改变社交环境中其他动物的行为。例如，在两个雌性有胡子的卷尾猴（Sapajus libidinosus）的繁殖期，他们向雄性扔石头并将树枝推向雄性，这可能会引起雄性对雌性的注意。为了进一步阐明这种行为的社交和交流相关性，我们在观察的963小时内记录了在巴西利亚动物园的一个圈养小组（一名成年男性和四名女性）中所有使用物体的情况。此外，我们记录了典型的性行为的发生以及与投掷行为相关的男性行为量化变化。所有雌性都向雄性扔东西，例如石头和木棍（N= 205个事件）。其中一名雌性动物还在雄性动物附近砸东西（N = 72）。物体使用的两种形式与女性的性倾向有关。男性定向投掷增加了男性改变其行为的机会，特别是通过将注意力转移到投掷者身上，从而支持了将男性投掷作为一种交流行为的假设。然而，雌性在亲属情境（N = 2）和与人类（N = 102）和其他动物（N= 61）。因此，我们的结果表明，有针对性的投掷是一种灵活的行为，是在多种社会环境中出于不同目的而引发的。此外，我们的研究表明，考虑对象使用对潜在目标行为的影响可以帮助我们理解灵长类动物如何使用对象来介导交流。