The Wood Pigeon (Kereru) is a splendid bird and the aristocrat of the Columbidae family which includes doves. With its head, throat and upper breast and back a metallic green flecked with gold and with a purple sheen, its belly white and its eye, beak and feet crimson, it is truly a gorgeous bird. Unlike most birds, pigeons can drink without raising their heads to swallow. They lay one egg which is peculiarly long, narrow and white. Both adults brood the egg during the 28 day incubation period. The hen sits through the night and morning with the cock taking over from midday until the evening. Apart from Emperor penguins and flamingos, pigeons and doves are the only birds to produce food for their chicks. They feed their chicks, called squabs, crop-milk, a protein rich, cottage cheese like secretion from the crop wall. At first crop milk is the only food but, as chicks grow, regurgitated foods form an increasingly large share of the diet.