Agostini Ilaria, Visalberghi Elisabetta
Istituto di Scienze e Tecnologie della Cognizione, CNR, Rome, Italy.
Am J Primatol. 2005 Apr;65(4):335-51. doi: 10.1002/ajp.20120.
Foraging traditions in primates are becoming the subject of increasing debate. Recent evidence for such a phenomenon was recently provided for wild Cebus capucinus [Fragaszy & Perry, 2003]. To better understand the bases of animal traditions, one should examine intrapopulation behavioral variability and the influence of social context on within-group transmission of specific foraging patterns. We studied the variability of foraging patterns across age and sex classes, and the proximity patterns of juveniles to adults of both sexes in a group of wild tufted capuchin monkeys (Cebus nigritus) living in the Iguazu National Park, Argentina. Foraging activity was examined for a period of 9 months in terms of proportions of focal samples devoted to foraging on certain food targets, microhabitats, and supports, and using specific foraging patterns. Proximity analyses were performed to reveal patterns of association between juveniles and adults. Sex differences in foraging behavior were present and overrode age differences. Overall, males ate more animal foods, foraged more for invertebrates on woody microhabitats (especially large branches), palms, and epiphytes, and used lower and larger supports than females. Females ate more fruits, foraged more on leaves and bamboo microhabitats, and used smaller supports than males. Juveniles were similar to adults of the same sex in terms of food targets, foraging substrates, and choice of supports, but were less efficient than adults. Proximity patterns indicated that juvenile males stayed in close spatial association with adult males and preferentially focused their "food interest" on them. This phenomenon was less evident in juvenile females. The degree to which juveniles, especially males, showed some of the sex-typical foraging patterns correlated positively with their proximity to adults of the same sex. These findings suggest that the acquisition of foraging behaviors by juvenile males is socially biased by their closeness to adults of the same sex.
灵长类动物的觅食传统正成为越来越多争论的主题。最近，野生白喉卷尾猴（Cebus capucinus）出现了这种现象的最新证据[弗拉加齐和佩里，2003年]。为了更好地理解动物传统的基础，人们应该研究种群内的行为变异性以及社会环境对特定觅食模式在群体内传播的影响。我们研究了生活在阿根廷伊瓜苏国家公园的一群野生簇绒卷尾猴（Cebus nigritus）中觅食模式在年龄和性别类别上的变异性，以及幼年个体与成年两性的接近模式。在9个月的时间里，从用于在特定食物目标、微生境和支撑物上觅食的焦点样本比例以及使用特定觅食模式的角度，对觅食活动进行了研究。进行接近度分析以揭示幼年个体与成年个体之间的关联模式。觅食行为存在性别差异，且这种差异超过了年龄差异。总体而言，雄性食用更多的动物性食物，在木质微生境（尤其是大树枝）、棕榈树和附生植物上更多地捕食无脊椎动物，并且使用比雌性更低和更大的支撑物。雌性食用更多的水果，在树叶和竹子微生境上觅食更多，并且使用比雄性更小的支撑物。幼年个体在食物目标、觅食基质和支撑物选择方面与同性成年个体相似，但效率低于成年个体。接近模式表明，幼年雄性与成年雄性保持紧密的空间关联，并优先将其“食物兴趣”集中在成年雄性身上。这种现象在幼年雌性中不太明显。幼年个体，尤其是雄性，表现出某些性别典型觅食模式的程度与它们与同性成年个体的接近程度呈正相关。这些发现表明，幼年雄性觅食行为的习得在社会层面上受到它们与同性成年个体接近程度的影响。
