Stead Samantha M, Mujjuzi Edward, Teichroeb Julie A
Department of Anthropology, University of Toronto Scarborough, Toronto, Ontario, Canada.
Rwenzori Colobus Project, Nabugabo, Masaka District, Uganda.
Am J Primatol. 2025 Jun;87(6):e70056. doi: 10.1002/ajp.70056.
A range of ecological and social factors have been shown to affect early-life behaviour in mammals. Primate infants are altricial and thus unable to move independently at birth. As a result, infants in some species are continuously held or carried (handled) by their mother or another caregiver (allomother). Variation in the amount of time infants move independently can provide insight into the costs and benefits associated with this developmental milestone. In this study, we sought to investigate what environmental conditions are associated with independence in an arboreal primate, the Rwenzori Angolan colobus (Colobus angolensis ruwenzorii). We followed 29 infants from birth until 4 months, collecting data on whether the infant was handled or independent. We report the age-sex make up of infant handlers and show that fruit availability was positively associated with infant independence, and maternal movement frequency was negatively associated with infant independence. We suggest that greater maternal energy balance during early infancy allows mothers to divert more energy to infants, promoting their independent movement. Further research should assess the maternal physiology underlying these trends and whether earlier independent movement has long-term fitness effects.
一系列生态和社会因素已被证明会影响哺乳动物的早期行为。灵长类动物幼崽出生时发育不全，因此出生时无法独立行动。因此，一些物种的幼崽会被母亲或其他照顾者（异亲）持续抱持或携带（照料）。幼崽独立活动时间的差异可以洞察与这一发育里程碑相关的成本和收益。在本研究中，我们试图调查哪些环境条件与一种树栖灵长类动物——鲁文佐里安哥拉疣猴（Colobus angolensis ruwenzorii）的独立行为有关。我们跟踪了29只幼崽从出生到4个月大的情况，收集有关幼崽是被照料还是独立的数据。我们报告了照料幼崽者的年龄性别构成，并表明水果供应量与幼崽的独立性呈正相关，而母亲的活动频率与幼崽的独立性呈负相关。我们认为，婴儿期早期母亲更好的能量平衡使母亲能够将更多能量转移给幼崽，促进它们的独立行动。进一步的研究应该评估这些趋势背后的母体生理机制，以及更早的独立行动是否具有长期的健康影响。
