Global movement patterns of migratory birds illustrate their fascinating physical and
physiological abilities to cross continents and oceans. During their voyages, most birds land …

For almost 40 years, studies of whole-organism performance have formed a cornerstone of
evolutionary physiology. Although its utility as a heuristic guide is beyond question, and we …

The common swift (Apus apus) is adapted to an aerial lifestyle, where food and nest material
are captured in the air. Observations have prompted scientists to hypothesize that swifts stay …

Being airborne is considered to be energetically more costly as compared with being on the
ground or in water. Birds migrating or foraging while airborne are thought to spend some …

Animals need a well-functioning immune system to protect themselves against pathogens.
The immune system, however, is costly and resource trade-offs with other demands exist …

Mercury is a global pollutant that has been widely shown to adversely affect reproduction
and other endpoints related to fitness and health in birds, but almost nothing is known about …

In many animals, catabolic and anabolic periods are temporally separated. Migratory birds
alternate energy expenditure during flight with energy accumulation during stopover. The …

Background The development, maintenance, and use of immune defences are costly.
Therefore, animals face trade-offs in terms of resource allocation within their immune system …

Migration is energetically demanding and physiologically challenging. Migrating birds, for
example, need to boost their antioxidant defenses to defeat the pro‐oxidants produced …

Stress-induced effects on innate immune activity in wild birds have been difficult to predict.
These difficulties may arise from the frequent assumptions that (1) the stress response …