Alderney is famous for not containing any large mammals in its terrestrial habitats. Deer, foxes, badgers, stoats and weasels are all absent from the island.

However, Alderney is home to a multitude of small mammals with the likes of bats and hedgehogs (including the rare 'blonde' or leucistic form) resident across the island. The waters around Alderney also host species of marine mammals, including a breeding colony of grey seals.