Abstract
Yearly, migratory birds travel between their wintering and breeding grounds via a number of distant stop-over sites. Why birds use a particular route and follow a particular migration schedule and what the implications will be of environmental changes along their flyways, have rarely been addressed. However, new theoretical advances have now created considerable potential to provide an understanding of the connection between migration and ecological, evolutionary and conservation issues. In particular, state-dependent models have proved useful in elucidating migratory patterns. These models explicitly take into account the state of individuals as a result of their behaviour and their interactions with conspecifics and the environment. Therefore, they can assist in analysing the fitness consequences of animal movements in space and time, integrating existing empirical knowledge and generating insights in the mechanisms underlying animal distributions and numbers. We aim to develop an annual routine model and to obtain general insights into what shapes long-distance migration in birds, to estimate consequences of potential environmental changes and thus, to establish a basis for future management. In particular, we will 1) identify key processes in the annual cycle of migratory birds including processes that show their effects in a delayed manner (knock-on effects), 2) evaluate the impact of environmental change (i.e. climate and habitat) along flyways, 3) explore the degree to which different species may adapt to changes and thereby identify timescales for changes and 4) elucidate the evolution of migratory pathways. These topics will not only be explored theoretically but the model will be applied to specific species from different ecological groups namely swans, geese and waders that cover a range of body masses (3 orders of magnitude) and life-histories.
Netherlands