Chemical composition of growth in nestling blackbirds and thrushes

摘要: 1. The bodies of twenty-three nestling blackbirds and twenty-one thrushes were analysed at different ages for water, fat, nitrogen, calcium, phosphorus, sodium, potassium magnesium. These birds grow from a weight 5 g hatching to 70 50 respectively when they leave the nest 12–13 d later.2. concentration N in doubled, while Ca increased seven eight times during this period, so that total amount body by about 100 times.3. femurs newly hatched very immature contained little or collagen but fledgelings as well calcified those 17-d-old chicks.4. gastro-intestinal tracts large amounts Ca. Their food consists caterpillars, adult insects earthworms, none which have much their tissues gut contents may contain It is suggested it these invertebrates provide with