1. Nest predators:
Eastern bluebirds nest in cavities, often in trees, and their nests are vulnerable to predators that can reach the cavity. Some common nest predators of Eastern bluebirds include:
- Snakes: Various snake species, such as black rat snakes and eastern rat snakes, are adept at climbing trees and can reach bird nests.
- Squirrels: Squirrels, particularly gray squirrels and fox squirrels, are known for raiding bird nests for eggs and nestlings.
- Blue jays: Blue jays are opportunistic nest predators and may target Eastern bluebird nests, especially when food is scarce.
- House wrens: House wrens are known to destroy the eggs of other bird species, including Eastern bluebirds, to compete for nesting sites.
2. Aerial predators:
While in flight, Eastern bluebirds are vulnerable to predators that hunt in the air. Some common aerial predators of Eastern bluebirds include:
- Accipiters: Accipiters, such as the Cooper's hawk and sharp-shinned hawk, are birds of prey that are well-adapted for hunting small birds.
- Falcons: Falcons, such as the American kestrel, are fast-flying predators that can catch birds in mid-air.
- Owls: Owls, particularly Eastern screech-owls and barn owls, are nocturnal predators that hunt small birds at night.
- Shrikes: Loggerhead shrikes are carnivorous birds that impale their prey on thorns or barbed wire, and they may target Eastern bluebirds.
3. Other predators:
In addition to these specific predators, Eastern bluebirds may also fall prey to other animals when roosting or when on the ground. These may include larger carnivorous mammals, such as foxes, raccoons, and feral cats.