Native peoples have often been portrayed as natural conservationists, living in ''harmony'' with their environment. It is argued that this perspective is a result of an imprecise definition of conservation that emphasizes effects rather than actual behavior. Using foraging theory as a contrast, an operational definition of conservation is offered. Foraging theory assumes that foragers will behave to maximize their short-term harvesting rate. Hunting decisions that are costly in terms of short-term harvest rate maximization, yet increase the sustainability of the harvest are deemed conservation. Using this definition, alternative hypotheses are tested using data on the inter-specific prey choice decisions of a group of subsistence hunters, the Piro of Amazonian Peru. Results indicate that hunters do not show any restraint from harvesting species identified as vulnerable to over-hunting and local extinction. Decisions are made that are consistent with predictions of foraging theory.