|Avian migration: Temporal multitasking and a case study of melatonin cycles in waders|
Helm, B.; Gwinner, E.; Koolhaas, A.; Battley, P.F.; Schwabl, I.; Dekinga, A.; Piersma, T. (2012). Avian migration: Temporal multitasking and a case study of melatonin cycles in waders. Progress in brain research 199: 457-479
In: Progress in brain research. ISSN 0079-6123, meer
clock; circannual; annual; tidal; circadian; moon; bird
|Auteurs|| || Top |
- Helm, B.
- Gwinner, E.
- Koolhaas, A., meer
- Battley, P.F.
- Schwabl, I.
- Dekinga, A., meer
- Piersma, T., meer
Timing “in the real world” must cope with the temporal complexity of natural environments.Extreme examples for the resultant “multitasking” are migratory birds, which precisely time movementsto remote areas. New field technologies highlight temporal accuracy, while captivity studies emphasizeunderlying programs and plasticity of schedules. After reviewing these findings, we focus on waders,which undertake spectacular long-distance migrations, have robust circannual clocks, and cope with diel, tidal, and polar environments. To explore features that may facilitate such multitasking, we speculated that melatonin amplitudes are low and damped during seasons when entrainment to subtle Zeitgebers occurs. We measured melatonin profiles under European daylength in two species with different ecologies and found low-amplitude melatonin cycles that changed over the year. Annual patterns neither fully supported our hypothesis, nor simply reflected daylight availability. While migratory birds are inspiring models for chronobiology, mechanistic understanding of their multitasking is still poor.