Data for: How should a clever baboon choose and move rocks? CM-July2020

Published: 07-10-2020| Version 1 | DOI: 10.17632/7djg2dbzw9.1
Celesté Maré


Herewith the raw data used for all analyses in the manuscript entitled: How should a clever baboon choose and move rocks? Chacma baboons intentionally overturn rocks to feed on the invertebrates beneath. However, baboons do not move all the rocks they encounter, with this presumably reflecting cost-benefit (or effort-reward) trade-offs in their foraging behavior. We asked, how do “clever baboons” choose rock sizes and shapes and move these rocks? All data were collected from 41 transects spread across four habitat types of the semi-Arid Karoo in the Eastern Cape, South Africa. Data collected were based on observations of moved and unmoved rocks encountered along the transects. Sheet 1 (Quantifying Baboon Rock Movement): Contains descriptive variables collected on the rocks moved by baboons and those left unmoved. These data were used to estimate baboon preferences for rock shape and size classes. These data were also used to calculate and compare the work (in J) required to move rocks along their shortest (width) and longest (length) axes. Data for flat rocks were used to test whether baboons moved rocks along their shortest or longest axis more often. Sheet 2 (Estimating Reward): Contains data collected on invertebrate burrows that we encountered beneath a sample of the moved and unmoved rocks. These data were used to show a relationship between rock size and the number of invertebrate burrows encountered beneath the rocks. We also used these data to determine the interactive effects of rock size and invertebrate abundance on the probability of rock movement by baboons. Our results showed that baboons have clear preferences for specific rock sizes (medium-sized) and shapes (angular and flat when these were medium-sized), and the way in which rocks are moved (along the shortest axis). Prey occurred infrequently under rocks. The low predictability of prey beneath rocks suggest that such prey, when encountered, is of considerable value to baboons for them to expend the search effort, and also explains the extensive nature of rock movement by baboons in the landscape.