Ecology and life history of alpine birds

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ECOLOGY AND LIFE HISTORY OF ALPINE BIRDS - Birds, the most widespread terrestrial vertebrates, breed from 0-6000 m asl. I use alpine specialists and 'elevational generalists' as model species to examine the ecology and life history variation of birds in relation to elevation and environmental variation. Animals in the alpine experience more variation and stochasticity in abiotic parameters (temperature, wind, precipitation, snow cover) than those breeding at lower elevations and latitudes. Daily temperatures range from <0 to >40 degC, but alpine birds must provide the same buffered thermal regime to incubate eggs and rear young as other birds. Our initial research reveals that as elevation increases, birds have 60% less time to breed and produce 50-60% fewer offspring annually compared with birds at lower elevation (LE). Alpine songbirds have 15-20% higher survival than LE conspecifics, offsetting at least partially their fecundity disadvantage. My working hypothesis is that selection operates on several vital rates and behaviours to allow birds breeding at high elevation (HE) to shift to a slower life style where increased survival of adults and juveniles compensates for lower annual fecundity (required for a tradeoff). We will investigate the longevity, breeding phenology, fecundity and behaviour of songbirds and grouse to determine the general coping abilities at HE using temperature and activity data loggers and behaviour studies on marked birds across latitudes. For species well adapted to HE, our objectives are to determine the physiological adaptations and/or genetic differentiation that allow survival-fecundity tradeoffs, the mechanisms whereby populations can shift their life history along an environmental gradient, which selective forces drive the tradeoff, and the role of plasticity in vital rates. Most studies assume that arctic and alpine habitats are comparable environments, but the key drivers shaping avian life histories may differ. Alpine habitats are experiencing globally significant increases in warming, habitat upshifting and extreme weather. Our research will determine net effects and improve predictions for climate change impacts on alpine vertebrates. I will train 16 HQP (10 PhD, 3 MSc, 3 PDF) and >60 BSc HQP.