Publications (2)20.62 Total impact
-
Article: The ecology and evolution of partial migration
[show abstract] [hide abstract]
ABSTRACT: Partial migration, where populations of animals are composed of a mixture of resident and migratory individuals, is a widespread phenomenon in nature. It has been reported to occur in all major vertebrate groups, and can have significant ecological consequences. Here we give an overview of the ecology and evolution of partial migration in animals. We firstly review the different types of partial migration, and assess the ecological drivers responsible for driving individual differences in migratory tendency within populations. A variety of factors can be important in promoting the evolution of partial migration, including competition for resources or breeding opportunities, predation risk and intraspecific niche diversity. Often various factors act synergistically to create complex patterns of movement polymorphism within populations. The question of how partial migration is maintained over evolutionary timescales is also addressed. Whilst many theoretical considerations of partial migration utilise an evolutionary stable state (ESS) paradigm, empirical evidence for this is lacking. Rather the evidence suggests that partial migration is mostly condition dependent, and the optimum outcome for an individual is dependent upon its phenotype. What determines whether an individual follows a migratory or resident strategy is discussed in light of new theory and empirical data which supports the idea that environmentally responsive genetic thresholds are important across a range of species, from birds to fish, in proximately shaping migratory tendency. Finally we espouse our vision of how partial migration research will develop in the future, and suggest a number of exciting directions that studies into migratory dimorphism may take in the coming years.Oikos 11/2011; 120(12):1764 - 1775. · 3.06 Impact Factor -
Article: To boldly go: individual differences in boldness influence migratory tendency.
[show abstract] [hide abstract]
ABSTRACT: Partial migration, whereby only a fraction of the population migrates, is thought to be the most common type of migration in the animal kingdom, and can have important ecological and evolutionary consequences. Despite this, the factors that influence which individuals migrate and which remain resident are poorly understood. Recent work has shown that consistent individual differences in personality traits in animals can be ecologically important, but field studies integrating personality traits with migratory behaviour are extremely rare. In this study, we investigate the influence of individual boldness, an important personality trait, upon the migratory propensity of roach, a freshwater fish, over two consecutive migration seasons. We assay and individually tag 460 roach and show that boldness influences migratory propensity, with bold individuals being more likely to migrate than shy fish. Our data suggest that an extremely widespread personality trait in animals can have significant ecological consequences via influencing individual-level migratory behaviour.Ecology Letters 07/2011; 14(9):871-6. · 17.56 Impact Factor
