Adélie penguins mainly build their nests from stones.
A breeding pair gathers pebbles and larger small stones to create a raised nest on the rocky Antarctic coast. The platform helps keep the eggs above meltwater and damp ground during the breeding season. Penguins may steal stones from nearby nests, creating competition within crowded colonies.
Adélie penguins usually lay two eggs. Both parents take turns incubating them and later feeding the chicks. The nest itself is not a deep cup like a songbird’s nest; it is a simple mound or platform assembled from available rocks.
Snow is generally a poor nest material because it can melt or collapse. Stones remain useful even in places where snow is present, which is why rocky breeding sites are important to the species.