Food for Thought:  Cognition & Foraging Efficiency of Neotropical Frugivores

Increasing brain size is a defining feature of human evolutionary history. Because brain tissue is metabolically expensive, a central question about human origins is how our ancestors acquired the additional energy necessary to grow and maintain large brains. Current hypotheses focus on relatively recent behavioral changes, suggesting that meat-eating, food processing or cooking increased diet quality and led to higher net energy gain. However, brain expansion is not restricted to the human lineage; it is an older and more general pattern across the primates. This suggests that a more fundamental process is responsible for the early stages of this energetically expensive brain expansion. One hypothesis is that primates possess a sophisticated ‘mental tool-kit’ that enables them to extract resources from their habitat more efficiently than other species. However, it has been impossible to adequately evaluate this hypothesis because we lack the critical comparative data. 

Memory Impacts Space Use.  The output of a simple agent-based foraging model illustrates how differences in how many food trees frugivores can remember, and how long that memory lasts, can dramatically change patterns of foraging behavior.

The aim of this project is to test if primates forage ‘smarter’ or ‘better’ than other fruit-eating species. The movements of six frugivorous mammals will be recorded using GPS tracking during an ecologically simple time of year when only one major fruit source is available. By comparing how distantly related, but ecologically similar species living in the same habitat, find food, this project will test if
 
    1) patterns of movement and food exploitation are consistent           with species-level differences in what animals know about           their habitat, and
    2) if complex foraging strategies lead to more efficient           
        resource acquisition.

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