In biparental species, females are thought to accept and even to seek male assistance in rearing of the young. In this study, we present data that suggests that Goeldi's monkey females (Callimico goeldii) actually reject male parental care for a certain period. In Callimico, which have biparental care, mothers carry the infant exclusively for the first three weeks despite the fact that fathers are interested in their infants directly after birth. Fathers initiated significantly more body contact with their mates when newborn infants were present and retrieved one-day-old infants that were experimentally presented to them. The onset of paternal carrying in our colony was 27.5 days compared to 11.5 days (medians) observed in the field. However, presentation of a live potential predator induced earlier onset of paternal carrying by about 10 days. Additional costs to maternal carrying such as foraging and predator avoidance are likely factors influencing the decision of the mother as to when to share the cost of infant carrying with the father. We conclude that Goeldi's monkey fathers start carrying their infants so late because they do not get them earlier from the mother. We suggest that one ultimate explanation for that delay might be increased infant mortality when infant transfer starts at an earlier stage.

中文翻译：

---

母亲而不是父亲决定了在戈尔迪的猴子（Callimico goeldii）中雄性携带的延迟发作。

在双亲物种中，雌性被认为接受甚至寻求雄性的抚养。在这项研究中，我们提供的数据表明，Goeldi的雌性猴子（Callimico goeldii）实际上在一定时期内拒绝雄性父母的照料。在拥有双亲照顾的卡利米科（Callimico），尽管父亲对分娩后的婴儿产生了兴趣，但母亲只在头三周才进行婴儿的育婴。当新生婴儿在场时，父亲开始与他们的伴侣进行更多的身体接触，并从实验中发现了一个一日大的婴儿。父亲在我们殖民地的发病时间为27.5天，而在野外观察到为11.5天（中位数）。然而，有生命的天敌掠食者的出现导致父本携带者提前约10天发病。母体携带的额外费用，例如觅食和避免捕食，可能是影响母亲决定何时与父亲分担婴儿携带成本的决定的因素。我们得出的结论是，Goeldi的猴子父亲这么晚才开始生婴儿，因为他们没有从母亲那里早点得到它们。我们建议，对于这种延迟的最终解释可能是当婴儿转移较早开始时婴儿死亡率增加。