Biro Dora, Muschinski Jana, Hammond Philippa, Bobe René, Bamford Marion K, Capelli Cristian, d'Oliveira Coelho João, Farassi Rassina, Lüdecke Tina, Martinez Felipe I, Mathe Jacinto, Silva Maria Joana Ferreira, Carvalho Susana
Department of Brain and Cognitive Sciences, University of Rochester, Rochester, New York, USA.
Primate Models for Behavioural Evolution Lab, Institute of Human Sciences, School of Anthropology and Museum Ethnography, University of Oxford, Oxford, UK.
Am J Biol Anthropol. 2025 May;187(1):e70057. doi: 10.1002/ajpa.70057.
Baboons possess sophisticated physical and social cognitive abilities; hence, the lack of evidence to date of large-scale behavioral variation in these primates is puzzling. Here we studied a candidate for such variation-the stripping of bark from Acacia robusta trees for consumption of the sap and soft tissue underneath-in Gorongosa National Park, Mozambique.
We surveyed an area inhabited by ~60 troops of chacma baboons, recording the availability and characteristics of the target trees, as well as the presence or absence of bark-stripping at 45 habitat plots distributed across a grid covering an area of ~300 km.
Camera traps confirmed the presence of baboons at all habitat plots, and we identified regional clumping in the distribution of the behavior, a pattern consistent across two consecutive years. Proportion and mean height/width of A. robusta did not predict whether bark-stripping behavior was present at a given site, nor did broader ecological variables such as habitat type and distance to the nearest water source. However, stripping sites had significantly higher numbers of A. robusta than non-stripping sites, and within a given bark-stripping site, baboons preferred to strip taller and wider trees among those available.
The prominent geographical clustering we uncovered may have been driven by opportunity (i.e., the prevalence of A. robusta at a given site), but is also consistent with a possible (non-mutually exclusive) cultural interpretation. We propose avenues for future research on Gorongosa's baboons to better quantify the relative contributions of ecology, genetics, and social learning to the prevalence of bark stripping. We also briefly consider the potential relevance of baboon bark stripping to elucidating early hominin foraging strategies.
狒狒具备复杂的身体和社会认知能力；因此，迄今为止缺乏这些灵长类动物大规模行为变异的证据令人费解。在此，我们在莫桑比克的戈龙戈萨国家公园研究了这种变异的一个候选行为——剥去强壮金合欢树的树皮以获取树皮下的树液和软组织。
我们调查了约60群东非狒狒居住的区域，记录目标树木的可用性和特征，以及在覆盖面积约300平方千米的网格中分布的45个栖息地地块是否存在剥树皮行为。
相机陷阱证实所有栖息地地块都有狒狒出现，并且我们确定了该行为分布的区域聚集现象，这一模式在连续两年中保持一致。强壮金合欢树的比例和平均高度/宽度并不能预测给定地点是否存在剥树皮行为，更广泛的生态变量如栖息地类型和到最近水源的距离也不能预测。然而，有剥树皮行为的地点的强壮金合欢树数量明显多于没有剥树皮行为的地点，并且在给定的有剥树皮行为的地点内，狒狒更喜欢在可用的树木中剥更高更宽的树的树皮。
我们发现的显著地理聚集现象可能是由机会驱动的（即给定地点强壮金合欢树的普遍程度），但也与一种可能的（并非相互排斥的）文化解释相一致。我们提出了未来对戈龙戈萨狒狒进行研究的途径，以更好地量化生态、遗传和社会学习对剥树皮行为普遍程度的相对贡献。我们还简要考虑了狒狒剥树皮行为对于阐明早期人类觅食策略的潜在相关性。
