title: Energy flow and the vertical structure of real ecosystems.
abstract: Three possible explanations for the well-known limitation of food chain lengths to two or three links for the most part are subjected to an empirical test, using the fact that ectotherms, especially invertebrates, tend to have higher production efficiencies than endotherms. The data are consistent with the hypothesis that food chain lengths are limited by the availability of energy.
authors.affiliation: Department of Zoology, University of Guelph, N1G 2W1, Guelph, Ontario, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Yodzis