The flow of copper through a terrestrial food chain : III. Selection of an optimum copper diet by isopods.

Groups of "cooper-enriched" and "copper-deficient" isopods were allowed to choose between three batches of birch litter differing in their copper contents. The relative amounts of litter ingested by the three species were the following (ranges of average contribution of each type of litter to total amount ingested): Thus the selection of food in these animals appears to be influenced by the status of the copper reserves in their bodies.