My project will focus on spatial and individual heterogeneity in reproductive success of snow buntings (Plectrophenax nivalis), and how such variation is linked to spatial environmental and microclimatic variation. For instance, rapid changes in timing of spring onset, and increased summer warming, likely affects the availability of nest sites and the abundance/activity of arthropods, the main food source for snow bunting chicks. Although such spatial or individual variation in the environment, as well as in the climate change effects, may have implications for the population's viability at large spatial scales, the extent and implications of such spatial effects are largely unknown. To assess this, I will monitor breeding data and arthropod abundance across the entire 2022 breeding season, record nest-specific local climate by the aid of temperature loggers, and apply remote sensing data to assess the environmental variaton across the nests in the study area in Adventdalen. This will provide novel data and new insights into the spatial heterogeneity in the effects of environmental change on Arctic birds undergoing rapid climate warming.