Seasonal variations in the food intake of captive red grouse.

1. The daily food intake of captive red grouse was measured throughout the year. It was positively related to body weight and to daylength, and negatively to air temperature. Grouse ate more during their main summer moult, and the hens ate most while producing eggs. 2. The total weight of eggs laid was positively related to daily food intake during the 5 weeks before laying, but not to daily intake during laying. The rate at which eggs were laid was related to daily intake during laying as well as before laying. The possible significance of these results for poultry management is discussed.