View article

We collected data 1984-1997 from northern Sweden (130 000 km 2) to investigate how moose (Alces alces) population dynamics might respond to among-year variations in food caused by weather. We obtained data from a dense network of weather stations, and collected two important moose foods of different growth forms at these stations every year at the same time. To index the growth rate of moose calves, we collected data on the mass of 7688 moose calves harvested by hunters during these years.

Our analysis revealed large variations (19%: 55.7-66.3 kg) among years in calf mass. This variation was related to weather, plant phenology and nitrogen content in food. Overall, the principal component describing June weather (precipitation and temperature) explained 35% of the annual variation in calf mass, with a warmer and dryer June (the calves' first month of life) associated with reduced body mass in …