Isbell Lynne A, Young Truman P
Department of Anthropology, University of California-Davis, Davis, CA 95616, USA.
Am J Primatol. 2007 Dec;69(12):1387-98. doi: 10.1002/ajp.20444.
The ants that live in the swollen thorns (domatia) of Acacia drepanolobium are staple foods for patas monkeys (Erythrocebus patas). To obtain a better understanding of these insects as resources for patas monkeys, we sampled the contents of 1,051 swollen thorns (ant domatia) over a 22-month period from December 1999 to September 2001, in Laikipia, Kenya. First, we confirmed that of the four species of ants that live on A. drepanolobium, Crematogaster sjostedti, the competitively dominant ant in this system, does not rear significant brood in the swollen thorns and is therefore not a major food item of patas monkeys. Second, across the other three species that do use swollen thorns for rearing their brood, C. nigriceps, C. mimosae, and Tetraponera penzigi, the number of worker ants per swollen thorn increased with increasing competitive dominance. Third, although there was considerable month-to-month variation in the number of workers, immatures, and especially alates (winged reproductives) within species, there was less variation across species because ant production was asynchronous. Variation in domatia contents was poorly related to rainfall for each of the three species. Finally, distal thorns held more alates and fewer workers than interior thorns, and branches higher off the ground held more alates and more workers than lower branches. For the numerically dominant C. mimosae, higher branches held significantly more immature ants than did lower branches. Ants are reliable food resources for patas monkeys, and are probably more reliable than many plant resources in this highly seasonal environment. We estimate that patas monkeys may get as much as a third of their daily caloric needs from these ants year-round. As ants and other insects are widely consumed by primates, we suggest that greater consideration be given to species differences in animal food choices and that further studies be conducted to examine the degree to which ants influence energy intake and reproduction in other primates.
生活在阿拉伯胶树（Acacia drepanolobium）膨大刺（蚁窝）中的蚂蚁是赤猴（Erythrocebus patas）的主要食物。为了更好地了解这些昆虫作为赤猴的食物资源，我们于1999年12月至2001年9月的22个月期间，在肯尼亚莱基皮亚对1051个膨大刺（蚁窝）的内容物进行了采样。首先，我们确认了生活在阿拉伯胶树上的四种蚂蚁中，在这个系统中具有竞争优势的斯氏举腹蚁（Crematogaster sjostedti）在膨大刺中不会大量育幼，因此不是赤猴的主要食物。其次，在另外三种确实利用膨大刺育幼的蚂蚁中，即黑举腹蚁（C. nigriceps）、含羞草举腹蚁（C. mimosae）和彭氏举腹蚁（Tetraponera penzigi），每个膨大刺中的工蚁数量随着竞争优势的增加而增加。第三，尽管每个物种内工蚁、未成熟个体尤其是有翅生殖蚁（有翅繁殖蚁）的数量存在相当大的月度变化，但由于蚂蚁的繁殖是异步的，物种间的变化较小。这三种蚂蚁中，蚁窝内容物的变化与降雨量的关系不大。最后，远端的刺比内部的刺有更多的有翅生殖蚁和更少的工蚁，离地面较高的树枝比较低的树枝有更多的有翅生殖蚁和更多的工蚁。对于数量占优势的含羞草举腹蚁来说，较高的树枝上未成熟蚂蚁的数量明显多于较低的树枝。蚂蚁是赤猴可靠的食物资源，在这个季节性很强的环境中，可能比许多植物资源更可靠。我们估计，赤猴全年从这些蚂蚁中获取的热量可能高达其每日热量需求的三分之一。由于灵长类动物广泛食用蚂蚁和其他昆虫，我们建议更多地考虑动物食物选择中的物种差异，并进一步开展研究，以考察蚂蚁在多大程度上影响其他灵长类动物的能量摄入和繁殖。
