Climate change affects populations over broad geographic ranges due to spatially autocorrelated abiotic conditions known as the Moran effect. However, populations do not always respond to broad‐scale environmental changes synchronously across a landscape. We combined multiple datasets for a retrospective analysis of time‐series count data (5–28 annual samples per segment) at 144 stream segments dispersed over nearly 1,000 line...

Human activities and climate change threaten coldwater organisms in freshwater ecosystems by causing rivers and streams to warm, increasing the intensity and frequency of warm temperature events, and reducing thermal heterogeneity. Cold‐water refuges are discrete patches of relatively cool water that are used by coldwater organisms for thermal relief and short‐term survival. Globally, cohesive management approaches are needed...

Genetic rescue is an increasingly considered conservation measure to address genetic erosion associated with habitat loss and fragmentation. The resulting gene flow from facilitating migration may improve fitness and adaptive potential, but is not without risks (e.g., outbreeding depression). Here, we conducted a test of genetic rescue by translocating ten (five of each sex) brook trout ( Salvelinus fontinalis ) from a single...

Estimating thermal performance of organisms is critical for understanding population distributions and dynamics and predicting responses to climate change. Typically, performance curves are estimated using laboratory studies to isolate temperature effects, but other abiotic and biotic factors influence temperature‐performance relationships in nature reducing these models' predictive ability. We present a model for estimating t...

Understanding how multiple extrinsic (density‐independent) factors and intrinsic (density‐dependent) mechanisms influence population dynamics has become increasingly urgent in the face of rapidly changing climates. It is particularly unclear how multiple extrinsic factors with contrasting effects among seasons are related to declines in population numbers and changes in mean body size and whether there is a strong role for den...

The effective number of breeders that give rise to a cohort ( N b ) is a promising metric for genetic monitoring of species with overlapping generations; however, more work is needed to understand factors that contribute to variation in this measure in natural populations. We tested hypotheses related to interannual variation in N b in two long‐term studies of brook trout populations. We found no supporting evidence for our in...

Climate change affects seasonal weather patterns, but little is known about the relative importance of seasonal weather patterns on animal population vital rates. Even when such information exists, data are typically only available from intensive fieldwork (e.g., mark–recapture studies) at a limited spatial extent. Here, we investigated effects of seasonal air temperature and precipitation (fall, winter, and spring) on surviva...

Migrations between different habitats are key events in the lives of many organisms. Such movements involve annually recurring travel over long distances usually triggered by seasonal changes in the environment. Often, the migration is associated with travel to or from reproduction areas to regions of growth. Young anadromous Atlantic salmon ( Salmo salar ) emigrate from freshwater nursery areas during spring and early summer...

The study of population dynamics requires unbiased, precise estimates of abundance and vital rates that account for the demographic structure inherent in all wildlife and plant populations. Traditionally, these estimates have only been available through approaches that rely on intensive mark–recapture data. We extended recently developed N ‐mixture models to demonstrate how demographic parameters and abundance can be estimated...

Linear and heterogeneous habitat makes headwater stream networks an ideal ecosystem in which to test the influence of environmental factors on spatial genetic patterns of obligatory aquatic species. We investigated fine‐scale population structure and influence of stream habitat on individual‐level genetic differentiation in brook trout ( Salvelinus fontinalis ) by genotyping eight microsatellite loci in 740 individuals in two...

Efforts to restore populations to locations from which they have been extirpated may be hampered by maladaptation in the introduced group because they came from a different environment. Estimates of natural selection acting on the new population can be used to deduce maladaptation and tailor efforts to reduce its effects. We estimated natural selection acting on Atlantic salmon ( Salmo salar ) undergoing restoration to the Con...