Predicting Consequences of Climate Change on Population Fluctuations of Birds and Mammals in Time and Space

The aim with the present project is to analyse how expected changes in climate will affect the population dynamics of birds and mammals, and how these dynamical influences will cause shifts in the geographical distribution of abundances within the distrib utional range of a species. Our approach will be to analyse in detail some carefully selected model systems for which long time series of individual-based demographic data as well as a mechanistic understanding of how climate influences the demography are available. This will alow us to parameterize stochastic population models that can be used to quantitatively evaluate climate influences on the population dynamics. By comparing systems with different population dynamical characteristics, we will identif y by sensititivity analyses whether some demographic parameters are more critical for strong responses to changes in climate than others. We will then develop theoretical models to identify conditions under which conditions temporal changes in climate are most likely to cause shift in the geographical distribution of abundance within a species' distributional range. We will focus these spatiotemporal analyses on three economically important systems of game species (Norwegian moose, grouse in Fennoscandia and North American waterfowls) in which population fluctuations are influenced by climate variation. By combining stochastic population models with regional scenarios for expected changes in climate as well as in enviornmental phenology, we can calculate how changes in climate will affect the spatial synchrony of the population fluctuations and how this will cause differences in the distribution of the abundance of the species within their distributional range. Such shifts will in turn affect the regiona l variation in the yield of these commerically important species. We will therefore exmine whether the effects of climate changes can be modified by altering the harvest strategies of these species.