As a youth Newton shot game birds – black or red grouse, common pheasant, partridge. Birds became an abiding interest. Those included the great bustard ("Otis tarda"), Montagu's harrier ("Circus pygargus"), ravens, buzzards ("Buteo" sp.), redpolls, wrynecks ("Jynx"), which are small woodpeckers that specialise in feeding on ants. "The vast warrens of the 'Breck', the woods and water-meadows of the valley of the Little Ouse, and the neighbouring Fenland made an ideal training-ground for a naturalist". This enthusiasm Newton shared with his younger brother Edward: the two carried out bird observation when they were together and corresponded when they were apart.