Squirrels do eat bird eggs, a behavior that is a normal part of their survival strategy as highly adaptable urban and suburban wildlife. Although often associated with nuts and seeds, squirrels are opportunistic feeders capable of consuming a wide range of food items. This allows them to exploit available resources, including the protein-rich contents of bird nests, especially when their nutritional demands are high.
Squirrels as Opportunistic Omnivores
Squirrels are classified as omnivores, which explains why they consume bird eggs. While their diet is overwhelmingly composed of plant matter like acorns, nuts, buds, and fungi, they readily supplement this with animal-based foods. This dietary flexibility is a significant survival advantage, particularly where traditional food sources fluctuate.
Bird eggs and nestlings are a concentrated source of high-quality protein and fat, important during the spring breeding season. Female squirrels, such as the Eastern Gray Squirrel (Sciurus carolinensis), often seek these nutrient-dense meals while pregnant or lactating to support the energy demands of raising their young. Eggs also provide essential minerals like calcium, which may be scarce in their typical plant-based diet. This predation is a consequence of their need to meet specific nutritional requirements.
Accessing Nests and Hunting Behavior
Squirrels possess physical attributes and sensory capabilities that make them highly effective nest predators. Their agility allows them to climb sheer surfaces, navigate thin branches, and leap distances of up to five feet horizontally to reach a nest site. This makes nests built in tree forks or on high, exposed branches particularly vulnerable to their approach.
Squirrels locate nests using a combination of visual cues and an acute sense of smell. They can detect the scent of parent birds, nest materials, and eggs, even when hidden. Once a nest is discovered, experience plays a role; studies show that predation rates increase significantly after a successful raid, suggesting a learned behavior. Open cup nests are generally at a higher risk than cavity nests, though squirrels may chew to enlarge the entrance holes of nest boxes to gain access.
Protecting Bird Nests from Squirrels
Homeowners concerned about protecting nesting birds can focus on physical modifications to the environment. The most effective strategy is the installation of baffles, which are physical barriers designed to prevent climbing access. A stovepipe or cone-style baffle should be mounted on any pole supporting a bird feeder or nest box, placed at least five feet off the ground.
The placement of bird feeders is also a factor, as feeders attract squirrels to the vicinity of nesting sites, increasing the chance of discovery. Poles for feeders and nest boxes must be positioned at least 10 to 12 feet away from any potential jumping-off point, such as fences or tree branches. Trimming tree limbs that overhang a birdhouse can eliminate the easy access route squirrels use to drop onto the roof. For nest boxes, attaching a metal plate around the entrance hole prevents squirrels from gnawing and widening the opening.