Skip to main content
Dryad logo

Data from: How do foragers decide when to leave a patch? A test of alternative models under natural and experimental conditions

Citation

Marshall, Harry H. et al. (2013), Data from: How do foragers decide when to leave a patch? A test of alternative models under natural and experimental conditions, Dryad, Dataset, https://doi.org/10.5061/dryad.3vt0s

Abstract

1. A forager’s optimal patch-departure time can be predicted by the prescient marginal value theorem (pMVT), which assumes they have perfect knowledge of the environment, or by approaches such as Bayesian-updating and learning rules, which avoid this assumption by allowing foragers to use recent experiences to inform their decisions. 2. In understanding and predicting broader scale ecological patterns, individual-level mechanisms, such as patch-departure decisions, need to be fully elucidated. Unfortunately, there are few empirical studies that compare the performance of patch-departure models that assume perfect knowledge with those that do not, resulting in a limited understanding of how foragers decide when to leave a patch. 3. We tested the patch-departure rules predicted by fixed-rule, pMVT, Bayesian-updating and learning models against one another, using patch residency times recorded from 54 chacma baboons (Papio ursinus) across two groups in natural (n = 6,594 patch visits) and field-experimental (n = 8,569) conditions. 4. We found greater support in the experiment for the model based on Bayesian-updating rules, but greater support for the model based on the pMVT in natural foraging conditions. This suggests that foragers may place more importance on recent experiences in predictable environments, like our experiment, where these experiences provide more reliable information about future opportunities.5. Furthermore, the effect of a single recent foraging experience on patch residency times was uniformly weak across both conditions. This suggests that foragers’ perception of their environment may incorporate many previous experiences, thus approximating the perfect knowledge assumed by the pMVT. Foragers may, therefore, optimise their patch-departure decisions in line with the pMVT through the adoption of rules similar to those predicted by Bayesian-updating.

Usage Notes

Location

Tsaobis Leopard Park
Namibia
15°45’E
22°23’S