Ecology and Life History of Mountain Birds

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ECOLOGY AND LIFE HISTORY OF MOUNTAIN BIRDS - Birds, the most widespread terrestrial vertebrates, breed from 0 to >6000m elevation. My overall research goal is to determine how birds solve the problems of living and breeding successfully in extreme mountain habitats. My students and I will examine ecological mechanisms for persistence in alpine bird populations, within species life history variation across elevation gradients, seasonal movements, larger scale studies on avian biodiversity patterns, and conservation threats to temperate mountain ecosystems.******Animals experience more variation and stochasticity in abiotic parameters (temperature, wind, precipitation, snow cover) in the alpine than those breeding at lower elevations. However, to incubate eggs and rear young, alpine birds must provide the same buffered thermal environment as other birds. In North America, alpine songbirds have up to 60% less time to breed and produce 50-60% fewer offspring annually compared with birds breeding 1 km lower. Nestlings develop more slowly at higher elevation and spend more days in the nest, incurring ecological costs (prolonged exposure to nest predation, prolonged parental investment). Some high elevation (HE) songbirds have 15-20% higher adult survival than low elevation (LE) conspecifics, offsetting at least partially their fecundity disadvantage. However, little is known about the physiological and ecological processes that produce these patterns, or their generality outside North America.******Our working hypothesis is that selection operates on physiology, vital rates and behaviours to allow HE birds to shift to a slower life style where increased survival of adults and juveniles compensates for lower annual fecundity. We aim to identify the physiological and ecological mechanisms (e.g., oxidative stress, telomere length, plasticity in vital rates) that enable this life history shift. In 2016-2021, we will use observations of marked and radio-tagged birds, complemented by temperature and activity data loggers to investigate the behaviour, fecundity, nestling development, and longevity of songbirds and grouse along elevational gradients in North and South America.******Alpine habitats are experiencing globally significant increases in temperature, habitat upshifting and extreme weather, but it is difficult to predict what will happen to birds because there is little information about avian use of alpine areas. We found that in North America 35% of birds use mountain habitats for one or more life history stages, and that habitat availability and connectivity will decrease strongly with climate change. In 2016-2021, we will examine avian densities and community composition among alpine, subalpine and montane habitats in the Chilean Andes. Our research will improve predictions for climate change impacts on persistence of alpine vertebrates. I will train 8 PhD, 3 MSc, 3 PDF and ~50 BSc HQP. **