Abstract
The climate is warming faster in the Arctic than in any other region on Earth and extreme variations in temperature and precipitation are becoming more common. Living at the northern edge of continents, breeding ranges of Arctic birds are expected to contract, potentially threatening their persistence. Most of these birds are migratory, only spending the summer in the Arctic. For many of these Arctic migrants, the Netherlands bears an international responsibility as large proportions of their populations stage or winter within its borders. Apart from range contraction, these birds are expected to be confronted with altered climate variability, trophic mismatches, and changing predation and snow conditions. Currently, it is unknown whether these pressures will translate into population declines and if so, whether and how mitigation measures at stopover or wintering sites are possible. There is an urgent need to assess climate change vulnerability and options for mitigation for this set of species that are so intimately linked to the Netherlands. In this project, we connect multiple disciplines to address this issue. We will integrate existing and novel bird data at individual and population level with state-of-the-art climate model simulations and vegetation modelling, in order to assess the vulnerability of arctic migrants to rapid climate change. As the basis, we will use the most recent and accurate state-of-the-art global climate models in a multimodel ensemble to downscale the climate information, and perform sensitivity simulations for relevant climate states. We will adapt and validate an existing dynamic Arctic tundra vegetation-model to simulate future changes in peak food availability using down-scaled climate change scenarios as input. We will use existing and newly collected bird tracking data of 10 species to link key phenological events (like onset of migration) to the optimal timing of reproduction. By deploying small radio-transmitters to chicks with different hatching dates, we will investigate to what extent bird reproduction is currently mistimed. Predation pressure on nests and chicks will be quantified by using camera traps and artificial nests, and by quantifying the functional response of key mammalian predators using tracking techniques. We will model the current habitat suitability of stopover, breeding and winter ranges using species distribution models and subsequently predict future changes in distribution. The modelling will include uncertainties under different scenarios of climate warming, and incorporate expected changes in biotic interactions such as predation. With mechanistic population models we will study how environmental factors like weather, food, and predation influence population size and staging duration, both under current and future climate scenarios. This enables us to quantify population vulnerability imposed by climate change. Our multidisciplinary and predictive approach will allow estimation of the cost-effectiveness of mitigation options at the winter and stopover sites to conserve Arctic migratory birds. Importantly, the project results will be summarized for policy makers in order to facilitate the translation of research into policy.
Netherlands