Migration is a wide-spread phenomenon across the animal kingdom as a response to seasonality in environmental conditions. Partially migratory populations are populations that consist of both migratory and residential individuals. Such populations are very common, yet their stability has long been debated. The inheritance of migratory activity is currently best described by the threshold model of quantitative genetics. The inclusion of such a genetic threshold model for migratory behaviour leads to a stable zone in time and space of partially migratory populations under a wide range of demographic parameter values, when assuming stable environmental conditions and unlimited genetic diversity. Migratory species are expected to be particularly sensitive to global warming, since arrival at the breeding grounds might be increasingly mistimed as a result of the uncoupling of long-used cues and actual environmental conditions, with decreasing reproduction as a consequence. Here we investigate the consequences for migratory behaviour and the stability of partially migratory populations under five climate change scenarios and the assumption of a genetic threshold value for migratory behaviour in an individual-based model. The results show a spatially and temporally stable zone of partially migratory populations after different lengths of time in all scenarios. In the scenarios in which the species expands its range from a particular set of starting populations, the genetic diversity and location at initialisation determine the species’ colonisation speed across the zone of partial migration and therefore across the entire landscape. Abruptly changing environmental conditions after model initialisation never caused a qualitative change in phenotype distributions, or complete extinction. This suggests that climate change induced shifts in species’ ranges as well as changes in survival probabilities and reproductive success can be met with flexibility in migratory behaviour at the species level, which will reduce the risk of extinction.
|Datum van beschikbaarheid||16 aug 2017|