Yahkat Barshep

Introduction Annual cycles of organisms have evolved to align seasonal activities with predictably fluctuating environmental conditions. As environments are rapidly changing, there is strong evidence that plants and animals are adjusting their phenology, i.e. the timing of seasonal processes (Walther et al. 2002). Although such adjustments occur at global scales, they typically differ between phases of the annual cycle, geographic locations and taxonomic groups (Walther et al. 2002, Thackeray et al.

Introduction Resource acquisition and allocation over the annual cycle of organisms is central to the evolution of life history strategies (Drent and Daan 1980, van Noordwijk and de Jong 1986, Lloyd 1988, Williams et al. 2017), and varies with species' ecologies and environmental conditions. In birds, moult – the shedding and replacement of feathers – is one of the primary annual cycle events, constrained by energetic and nutrient demands and important in self-maintenance and survival.