The ethics of wildlife research: a nine R theory.

The commonsense ethical constraints on laboratory animal research known as the three Rs are widely accepted, but no constraints tailored to research on animals in the wild are available. In this article, we begin to fill that gap. We sketch a set of commonsense ethical constraints on ecosystem research parallel to the constraints that govern laboratory animal research. Then we combine the animal and ecosystem constraints into a single theory to govern research on animals in the wild.