Muriwai's gannet colony is a one hour drive from the centre of Auckland. Out to sea, the colony continues on two vertical-sided islands. About 1,200 pairs of gannets nest here from August to March each year.The nests are just centimetres apart. It's an air traffic controller's nightmare, but somehow the birds have it under control. Those coming in to land must glide over the squawking raised beaks of their neighbours - so getting it wrong can be painful. These two-and-a-half kilogram birds have a wingspan of two metres, and their mastery of the onshore updrafts is impressive to say the least.Each pair lays one egg and the parents take turns on the nest. As the he chicks mature, they grow juvenile feathers and begin to exercise their wings in preparation for the one-shot jump off the cliff.Once airborne, the young gannets leave the colony and cross the Tasman Sea to Australia. A few years later, surviving birds return to secure a nest site at the colony.