Aim To demonstrate how the interrelations of individual movements form largescale population-level movement patterns and how these patterns are associated with the underlying landscape dynamics by comparing ungulate movements across species.Locations Arctic tundra in Alaska and Canada, temperate forests in Massachusetts, Patagonian Steppes in Argentina, Eastern Steppes in Mongolia. MethodsWe used relocation data from four ungulate species (barren-ground caribou, Mongolian gazelle, guanaco and moose) to examine individual movements and the interrelation of movements among individuals. We applied and developed a suite of spatial metrics that measure variation in movement among individuals as population dispersion, movement coordination and realized mobility. Taken together, these metrics allowed us to quantify and distinguish among different large-scale population-level movement patterns such as migration, range residency and nomadism. We then related the population-level movement patterns to the underlying landscape vegetation dynamics via long-term remote sensing measurements of the temporal variability, spatial variability and unpredictability of vegetation productivity. ResultsMoose, which remained in sedentary home ranges, and guanacos, which were partially migratory, exhibited relatively short annual movements associated with landscapes having very little broad-scale variability in vegetation. Caribou and gazelle performed extreme long-distance movements that were associated with broad-scale variability in vegetation productivity during the peak of the growing season. Caribou exhibited regular seasonal migration in which individuals were clustered for most of the year and exhibited coordinated movements. In contrast, gazelle were nomadic, as individuals were independently distributed and moved in an uncoordinated manner that relates to the comparatively unpredictable (yet broad-scale) vegetation dynamics of their landscape. Main conclusionsWe show how broad-scale landscape unpredictability may lead to nomadism, an understudied type of long-distance movement. In contrast to classical migration where landscapes may vary at broad scales but in a predictable manner, long-distance movements of nomadic individuals are uncoordinated and independent from other such individuals. Landscapes with little broad-scale variability in vegetation productivity feature smaller-scale movements and allow for range residency. Nomadism requires distinct integrative conservation strategies that facilitate long-distance movements across the entire landscape and are not limited to certain migration corridors.

ABStrACt. the annual migration of bowhead whales (Balaena mysticetus) past Barrow, Alaska, has provided subsistence hunting to Iñupiat for centuries. Bowheads recurrently feed on aggregations of zooplankton prey near Barrow in autumn. the mechanisms that form these aggregations, and the associations between whales and oceanography, were investigated using field sampling, retrospective analysis, and traditional knowledge interviews. Oceanographic and aerial surveys were conducted near Barrow during August and September in 2005 and 2006. multiple water masses were observed, and close coupling between water mass type and biological characteristics was noted. Short-term variability in hydrography was associated with changes in wind speed and direction that profoundly affected plankton taxonomic composition. Aggregations of ca. 50 -100 bowhead whales were observed in early September of both years at locations consistent with traditional knowledge. retrospective analyses of records for 1984 -2004 also showed that annual aggregations of whales near Barrow were associated with wind speed and direction. euphausiids and copepods appear to be upwelled onto the Beaufort Sea shelf during e or Se winds. A favorable feeding environment is produced when these plankton are retained and concentrated on the shelf by the prevailing westward Beaufort Sea shelf currents that converge with the Alaska Coastal Current flowing to the northeast along the eastern edge of Barrow Canyon. hydrographie était liée à des changements relatifs à la vitesse et à l'orientation du vent qui avaient de fortes incidences sur la composition taxonomique du plancton. Des agrégations d'environ 50 à 100 baleines boréales ont été observées au début septembre des deux années à des emplacements cadrant avec les connaissances traditionnelles. les analyses rétrospectives des données recueillies de 1984 à 2004 ont également montré que les agrégations annuelles de baleines boréales près de Barrow étaient liées à la vitesse et à l'orientation du vent. les euphausias et les copépodes semblaient remonter vers le plateau de la mer de Beaufort lorsque les vents étaient de l'est ou du sud-est. un milieu alimentaire favorable est créé lorsque le plancton est retenu et concentré sur le plateau par les courants de direction ouest du plateau de la mer de Beaufort qui convergent avec le courant côtier de l'Alaska s'écoulant vers le nord-est le long de la rive est du canyon de Barrow.

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ABSTRACT. Climate warming and resource development could alter key Arctic ecosystem functions that support fish and wildlife resources harvested by local indigenous communities. A different set of global forces-government policies and tourism markets-increasingly directs local cash economies that communities use to support subsistence activities. Agent-based computational models (ABMs) contribute to an integrated assessment of community sustainability by simulating how people interact with each other and adapt to changing economic and environmental conditions. Relying on research and local knowledge to provide rules and parameters for individual and collective decision making, our ABM generates hypothetical social histories as adaptations to scenario-driven changes in environmental and economic conditions. The model generates projections for wage employment, cash income, subsistence harvests, and demographic change over four decades based on a set of user-defined scenarios for climate change, subsistence resources, development, and government spending. Model outcomes assess how scenarios associated with economic and climate change might affect the local economy, resource harvests, and the well-being of residents for the Western Arctic Canadian community of Old Crow, Yukon. The economic and demographic outcomes suggest implications for less quantifiable social and cultural changes. The model can serve as a discussion tool for a fuller exploration of community sustainability and adaptation issues.Key words: community sustainability, integrated assessment, local knowledge, mixed economy, tourism, agent-based model, simulation, climate change, Old Crow, Yukon RÉSUMÉ. Le réchauffement climatique et la mise en valeur des ressources pourraient modifier des fonctions clés de l'écosystème arctique qui assurent le maintien des ressources ichtyques et fauniques exploitées par les collectivités autochtones locales. Un autre jeu de forces à l'échelle mondiale -les politiques gouvernementales et les marchés du tourisme -dirige de plus en plus les économies monétaires locales qu'utilisent les collectivités pour soutenir leurs activités de subsistance. Des modèles informatiques orientés agent (ABM) concourent à une évaluation intégrée de la viabilité des collectivités en simulant les interactions entre les personnes et leur adaptation aux conditions changeantes de l'économie et de l'environnement. S'appuyant sur des travaux de recherche et sur le savoir local afin de fournir règles et paramètres pour la prise de décisions individuelle et collective, notre ABM génère des histoires sociales fictives comme adaptations à des changements dans les conditions environnementales et économiques définis dans un scénario. Le modèle génère des projections pour l'emploi salarié, le revenu monétaire, les prélèvements de subsistance et le changement démographique au cours de quatre décennies. Ces projections sont fondées sur un ensemble de scénarios définis par l'utilisateur concernant le changement climatique, les ressources de subsistance, l...

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