Forest birds may be insectivores, frugivores, and nectarivores. Within the subclass Lepidosauria there are herbivores, omnivores, insectivores, and carnivores. Basal pterosaurs were insectivores or predators on small vertebrates. Some are herbivorous, others carnivorous, including seed-eaters, fish-eaters, insectivores, and omnivores. Mammalian prey for common buzzards other than rodents, insectivores and lagomorphs is rarely taken. Old World flycatchers are a large family of mainly small arboreal insectivores. There is some suggestion that the earliest primates were nocturnal, arboreal insectivores. Old World flycatchers are a large group of small arboreal insectivores. Early-on it was recognised that the small Anurognathidae were nocturnal, aerial insectivores. They are slender ground feeding insectivores of open country. They are slender, ground feeding insectivores of open country. They are slender ground-feeding insectivores of open country. These are slender ground-feeding insectivores of open country. They are slender, ground-feeding insectivores of open country. Frugivores are more social than the insectivores, which are more solitary and territorial.