Ecological scaling: mammals and birds
Abstract
The effort necessary to measure the differences in lifetime reproductive success in nature has already been described convincingly (20). All impregnations, births, and deaths that occur throughout the entire turnover of a wild population must be recorded. This process is both necessary and fascinating, but it is slow. The individual recognition and continuous surveillance necessary to accom plish this task are difficult, if not impossible, to attain with small animals; they require extremely long projects for large, conspicuous, and long-lived ones. In the interim, as our species is rivet-popping on Spaceship earth (27), we need to have a general pattern that we can use for comparative and predictive purposes (25). Has each life history evolved uniquely with random details that must all be described de novo, or is there a ground plan with design constants for an entire class or other major taxon (32, 60)? Body size is the predominant influence on an animal's requirements and opportunities for resource exploitation, thus providing a simple and powerful basis for revealing major patterns in life histories and population structure. The size-dependence of some variable (Y) has been expressed routinely as an exponential function of body mass (M. in kg) in the allometric equation:
Related Works
Items connected by shared entities, co-authorship, citations, or semantic similarity.