An avivore is a specialized predator of birds, with birds making up a large proportion of its diet. Such bird-eating animals come from a range of groups.
Birds that are specialized predators of other birds include certain accipiters and falcons. General features of avian avivores include a skull form which is well adapted for grasping and crushing with the beak, although not especially well structured for neck twisting motions. Bird-eating raptors also tend to show greater sexual dimorphism than other raptors, with the females being larger than the males.
Some avian avivores such as the shikra, besra, Eurasian sparrowhawk, and sharp-shinned hawk catch their prey by flying from cover in a tree or bush, taking their prey unawares. In contrast, the lanner falcon hunts in open country taking birds by horizontal pursuit. The aplomado falcon will use both ambush and more extended flights. The peregrine falcon dives on flying birds from a great height at speeds that can exceed 300 km/h.
In certain biotopes, birds constitute the bulk of the diet of various carnivorans, e.g., of adult leopard seals that mostly prey on penguins, the Arctic fox living in coastal areas where colonies of murres, auks, gulls and other seabirds abound and stoats in New Zealand against whom flightless birds like the takahē and kiwi are defenseless. Other mammals who occasionally prey on birds include most carnivora; a number of primates ranging from lorises and night monkeys over baboons and chimpanzees to humans; orcas; possums and other marsupials; rats and other rodents; hedgehogs and other insectivora and bats.
A number of mammal species are specialized predators of birds. The caracal and the serval, both medium-sized cats, are known for their leaping ability which they use to catch flying birds, sometimes two at a time. Some carnivora, including the red fox and martens, are known for engaging in surplus killing of birds. Kruuk (1972) observed that four red foxes killed 230 black-headed gulls in one night in a single colony at the Cumberland coast while fewer than 3% of the gulls showed any sign of being eaten. 
The egg-eating snake specializes in eating birds eggs, swallowing them whole and then breaking them using a protrusion from its spine.
The Goliath birdeater (Theraphosa blondi) was named by explorers who saw it eating a humming bird.