In many bird species, the proportion of sons and daughters (offspring sex ratio) can strongly deviate from the expected 50:50. This phenomenon has been observed in domestic species, e.g. chicken, quail, and pigeons, but also in wild species, such as gulls or parrots. Evolutionary theory predicts, that under certain circumstances mothers will gain an advantage by producing a biased offspring sex ratio, for example, when the chances to reproduce differs between the sexes. Still, the underlying mechanisms leading to a biased offspring sex ratio are largely unknown. Research suggests, that the body condition and the hormonal status of the breeding female is of high relevance.
Saturday, October 31, 2015 at 9:30
Wednesday, September 16, 2015 at 12:53
PEARCEDALE’S Moonlit Sanctuary is playing a key role in preventing the extinction of an extremely rare species of parrot.
Wednesday, September 16, 2015 at 12:42
Wild orange-bellied parrots being killed by virus; questions arise over source of beak and feather disease
Monday, September 14, 2015 at 12:26
The bird is on the brink of extinction with fewer than 70 birds thought to exist in the wild.
Thursday, September 10, 2015 at 12:49