When facing two sets of imprinting objects of different numerousness, domestic chicks prefer to approach the larger one. Given that choice for familiar and novel stimuli in imprinting situations is known to be affected by the sex of the animals, we investigated how male and female domestic chicks divide the time spent in the proximity of a familiar versus an unfamiliar number of objects, and how animals interact (by pecking) with these objects. We confirmed that chicks discriminate among the different numerousnesses, but we also showed that females and males behave differently, depending on the degree of familiarity of the objects. When objects in the testing sets were all familiar, females equally explored both sets and pecked at all objects individually. Males instead selectively approached the familiar numerousness and pecked more at it. When both testing sets comprised familiar as well as novel objects, both males and females approached the larger numerousness of familiar objects. However, chicks directed all their pecks toward the novel object within the set. Differences in the behavior of males and females can be accounted for in terms of sex difference in the motivation to reinstate social contact with the familiar objects and to explore novel ones, likely associated with the ecology and the social structure of the species before domestication.

当面对两组不同数量的印迹对象时，家禽更喜欢接近较大的一组。鉴于已知在印记情况下选择熟悉和新颖的刺激会受到动物性别的影响，我们研究了雌性和雌性家禽如何将花费在熟悉和不熟悉物体附近的时间进行划分，以及如何动物与这些物体互动（啄）。我们确认小鸡可以区分不同的人群，但是我们也表明雌性和雄性的行为有所不同，具体取决于对象的熟悉程度。当测试集中的对象都熟悉时，雌性会平等地探索这两个集合并分别啄食所有对象。男性反而有选择地走近了熟悉的人群，并对其进行了更多的啄食。当两个测试集都包含熟悉的物体和新颖的物体时，雄性和雌性都接近了许多熟悉的物体。但是，小鸡将所有啄子对准了该组中的新对象。可以通过性别差异来解释男性和女性行为上的差异，以恢复与熟悉对象的社会联系并探索新颖的动机，这很可能与驯化之前物种的生态和社会结构有关。