Snowier winters extend autumn availability of high‐quality forage for caribou in Arctic Alaska

Caribou (Rangifer tarandus) rely on the short Arctic growing season to restore body condition, support demands of lactation, and prepare for long arctic winter, making them susceptible even small changes in forage availability or quality. Body condition summer autumn is linked winter survival rates fecundity cows, critical factors productivity caribou populations. Climate change predictions warmer wetter northern winters suggest increased snowfall over Alaska's North Slope, which has recently been verified between 1995 2017. However, a comprehensive analysis how deeper snow will affect quality absent across Alaska. In this study, we quantify depth alters seasonality using long-term (24 yr) International Tundra Experiment manipulation evaluate climate scenarios may tussock tundra systems Deeper prior leads increases leaf N digestible protein (DP) deciduous shrubs (Salix spp. Betula spp.) graminoids (Carex Eriophorum spp.), but not evergreen dwarf (Rhododendron Vaccinium spp.). Dry matter digestibility varied among species with differences (<5%) associated depth. Most striking was discovery that duration DP levels above minimum threshold gain by as much 25 d Salix pulchra 6–9 nana Carex bigelowii late early autumn. Consequently, provide an extended window opportunity foraging accumulation lean mass fat reserves promote successful calving following spring potentially improve