Problems Inhibiting Energetic Analyses of Migration

Abstract

A major goal of students of avian migration is to understand the suite of factors that has produced the impressive diversity of migratory patterns observed in birds and the significance of such variation for the organism’s fitness. Prudence generally dictates suspicion of single-factor explanations for complex biological problems. In the case of avian migration, however, it seems likely that dissecting the energetic bases and consequences of variable migratory patterns will be a particularly fruitful approach. The behavior of birds in migration is largely directed toward the single task of moving long distances and the resource of overwhelming importance for this activity clearly is energy. This contrasts with other portions of the annual cycle such as reproduction, during which tactics for energy acquisition may be significantly complicated by simultaneous demands for nutrients such as protein (e.g., Drobney 1980). Such considerations strongly suggest that analyses of migration energetics are likely to yield substantial insights.