Abstract
The diet intake of Hazel Grouses Tetrastes bonasia adults was investigated in captivity in 1988 and from 1991 to 1993. Birds were fed on a mixture of commercial poultry rations and pet food with a supplement of fish meal from April to September. In addition, fibrous diets (Taraxacum officinale or Rumex obtusifolius from April to October and cabbage from November to March) were supplied. The mean (±SD) intake of diets in dry weight ranged from 17.0±2.2 to 20.9±2.7 g/bird/day for males and from 12.0±3.4 to 20.6±2.6 g/birds/day for females. The energy intake estimated based on diet intake and gross energy in diets ranged from 310.4±41.2 to 366.7±47.9 kJ/bird/day for males and from 220.7±63.3 to 379.2±48.6 kJ/bird/day for females. On the average, both diet and energy intake increased in winters and decreased in summers except for female in May and June. The increased energy intake of females in May might be related to the increased requirements for egg laying and decreased one in June was due to egg incubation. The mean body weight changed seasonally in both sexes, ranging from 344±7 g in May to 383±9 g in January for males and from 356±20 g in June to 412±31 g in May for females. The body weights of females were significantly larger than those of males in April and May. The diets used is nutritionally adequate in respect of seasonal changes in body weight which is similar to that in natural conditions. A standard diet for adults birds was presented based on the data for diet intake.
