Why Knot?: Exploration of variation in long-distance migration

Red knots (Calidris canutus) are shorebirds that spent most of the year at intertidal areas such as the Wadden Sea. However, once a year to and from their northern breeding grounds. Red knots yearly undergo a remodeling of their body to be physiologically prepared for the long flight and following reproductive season. Previous work has shown that many experienced migrants are very consistent in their migratory routines. The aim of this thesis is to increase understanding of the development of individual migratory routines. In the first part of this thesis, I first explore individual variation in migratory behaviour present in wild knots using a novel solar-powered satellite transmitter. In the second part of this thesis I investigate how differences in experience effect the development of physiological and behavioural traits in birds temporarily held in captivity. By combining these results I show that environmental conditions play a key role in shaping individual migratory routines. Expending on the role of experience in shaping individual differences I present a testing protocol aimed at testing cognitive aspects of migration, a fairly under represented topic in studies on migration. For future studies I suggest to combine tracking of individual birds with standardized assays to stimulate research into the cognitive aspects of migratory behaviour. Because I believe that the closer we are to understanding ‘what it is like to be a bird (or any other animal) the more we are able, and willing, to appreciate and protect the animals and the habitats that are around us