Marrow fat deposition and skeletal growth in caribou calves

I evaluated rates of marrow fat deposition and skeletal growth of caribou (Rangifer tarandus granti) calves through 20 days of age at Denali National Park, Alaska, USA. Both were negatively correlated with late winter snowfall, indicating the prolonged effects of maternal undernutrition following severe winters. Using regression analyses, I found that the rates of marrow fat deposition and hindfoot growth during the 20 days following birth declined 46% and 68%, respectively, over the range of winter severity during this study. These measures of development may indicate a broader array of effects of maternal undernutrition, influencing the vulnerability of caribou calves to predation.