Gannets use their foot webs to incubate the egg. The foot webs, which are richly irrigated with blood vessels are wrapped around the egg.
The hatchling is black, naked and blind, it weighs only about 70 g (2.5 oz), but within three weeks its body mass is one third of that of an adult. At eight weeks the chick outweighs the adult, and this remains so until it becomes a fledgling at 95–105 days of age.
They perform elaborate greeting rituals at the nest, stretching their bills and necks skywards and gently tapping bills together.