Why Do Bluebirds Attack Squirrels?

by Derrick | Last Updated: April 7, 2023

Bluebirds are very pleasant looking birds and the blue color gives them almost a peaceful look.  But like any wild animal if you mess with the animals home or young they will do everything they can to repel the threat including attacking the aggressor.

Why do bluebirds attack squirrels? Squirrels are rather known to intrude on a bluebird’s nest, consuming the eggs and occasionally, the young chicks and hatchlings. In certain circumstances, they have been seen to take up residence in the nest having ousted its original inhabitants. Because of this looming threat, Bluebirds, particularly the males, step up. They ardently defend their nest, eggs, hatchlings, and mate against invasions by squirrels and other rodents.

Predators to Bluebirds

Large rats, squirrels, chipmunks and raccoons considerably jeopardise bluebirds and their nestlings. Sparrows display particular disdain towards bluebirds, second only to squirrels. Bluebirds also have to contend with other predators like cats, snakes, frogs and even the seemingly unlikely coyotes, a grim reality often underscored by harrowing tales of bluebirds fighting valiantly against these aggressors.

Do squirrels eat bluebird eggs?

Yes, squirrels are opportunistic feeders and have been known to eat bird eggs, including those of bluebirds. While squirrels primarily eat nuts, seeds, fruits, and vegetation, they also consume insects, small animals, and bird eggs when available.

If squirrels find a nest with eggs, they may consume them as a source of protein.

Signs that a squirrel has managed to get into a bluebird’s nest include:

If a squirrel has managed to get into a bluebird’s nest, there might be some signs indicating this. Here are a few potential indications:

  1. Damaged or disturbed nest: If the nest appears to be disturbed, with nesting material scattered around the area or pulled out of the nesting box, this could be a sign that a squirrel has raided the nest.
  2. Broken or missing eggs: Squirrels will eat bluebird eggs, so if you find broken eggshells or notice that eggs are missing from the nest, it could be the work of a squirrel or another nest predator.
  3. Scratches or marks on the nest box: If you see scratches, teeth marks, or other signs of damage on the nesting box, it could be an indication that a squirrel has tried to access the nest.
  4. Squirrel tracks or droppings: Squirrel tracks or droppings near the nesting box could be a sign that a squirrel has been in the area and possibly raided the nest.
  5. Presence of squirrels: If you frequently see squirrels near the nesting box or birdhouse, there’s a higher chance that they could have accessed the bluebird’s nest.

Why Do Bluebirds Attack?

Bluebirds come off as elegant and gentle birds, who appear to be poor fighters when compared to other birds like sparrows or even starlings, crows and pigeons.

Bluebirds are a type of small thrush that are found throughout North America. They are easily recognized by their bright blue feathers, rust-colored breasts, and white bellies. These birds are known for their melodious songs and are often associated with happiness and good fortune.

While bluebirds may appear gentle and peaceful, they can be fierce fighters when it comes to defending their territory, mates, and offspring. One of the main reasons why male bluebirds fight is to ensure the paternity of their offspring. Unlike many other bird species, bluebirds are monogamous and mate for life. Male bluebirds closely monitor their partners to ensure their fidelity and may engage in physical altercations with other males to defend their mates.

During the breeding season, bluebirds are also fiercely protective of their nests, eggs, and chicks. They typically build their nests in cavities, such as hollowed-out trees, birdhouses, or fence posts. While the female bluebird incubates the eggs, the male stands guard and keeps watch for predators. If a predator, such as a squirrel or snake, approaches the nest, the male bluebird will usually try to chase it away. However, if the predator persists, a fight may ensue.

Bluebirds are also known to be aggressive towards other bird species that may encroach on their territory. They are known to fiercely defend their feeding and nesting areas, often driving off other birds that come too close. This behavior is not limited to other bird species, as bluebirds have been observed attacking other animals, such as snakes and chipmunks, that pose a threat to their nests or young.

Notwithstanding their defensive demeanour, bluebirds continue to win the hearts of bird watchers and nature enthusiasts alike. The allure of their splendid plumage, sweet melodies, and charismatic personalities cement their spot as a favourite amongst bird enthusiasts. They embody the essence of devotion and raw protective instinct, reflecting that even the most tender creatures harbour formidable strength and will when safeguarding what is precious to them. Indeed, these Bluebirds, with their silent resilience and celestial elegance, subtly impart a profound lesson about the persistence of nature itself.

Believe it or not, male bluebirds keep an eye out to make sure the female bluebirds stay monogamous. They guard their mates very closely and will know if their significant other has stepped out on them. Male-male bluebirds fight and show aggression mostly to assure and defend the paternity of their hatchlings and these battles can become quite intense, and sometimes be fatal or crippling.

Another reason for bluebirds to fight is, of course, to protect their nests, eggs or chicks from predators. During the spring and summer months, when the bluebirds nest, they get protective of their nests and guard it from prey.

If a squirrel gets too close to the nest, it will either be quickly chased off by the bluebird- usually the male bluebird- or if it is particularly persistent, a rather nasty scuffle will ensue between the two. As squirrels are known to attack and invade nests when they are empty of the parent bluebirds, either the male or the female will try to stay in the nest with the eggs or chicks at all times, while the other forages for food and keeps an eye out for predators.

Will A Squirrel Kill A Bird?

Yes, squirrels sometimes do kill birds. It depends largely on how big the bird is, in relation to how big the squirrel is.

Squirrels will pick fights with birds either smaller or at least the same size as itself, and will not venture into the nests of, or dare fight with larger birds, out of fear that it will get injured or killed in the process.

However, it must be noted that squirrels are primarily nest invaders, and egg or chick eaters. They mostly only kill and subsequently eat grown birds when they get into a fight trying to get into those nests to eat the eggs. They are not picky when it comes to their meals. While they are largely vegetarian and their diet consists mostly of acorns, nuts, lichens, fruits, roots, mushrooms, leaves and even insects, they do kill and eat birds too.

Why do squirrels eat birds? Squirrels, especially red squirrels, according to research, have a streak of vicious aggressiveness that make them kill their own pups.  Researchers believe that squirrels have been taught, over years and years in the wild, that only the fittest survive, and these little rodents will do anything to get food and to survive.

How To Keep Squirrels Away From Bluebirds’ Nest And Eggs

Here are some effective methods for keeping squirrels at bay:

  1. Install a Squirrel Baffle: A squirrel baffle is a device that prevents squirrels from climbing up a pole or tree to access the bluebird nest. The baffle can be made of metal or plastic and should be placed around the pole or tree trunk so that it extends at least two feet above and below the nest box. This will make it difficult for squirrels to climb up to the nest.
  2. Use a Cone-Shaped Guard: Another effective method for keeping squirrels away from bluebird nests is to use a cone-shaped guard. This guard can be made of metal or plastic and is placed over the nest box. The cone should be about 6-8 inches wide at the base and should extend at least 2 feet above the nest box. This will make it difficult for squirrels to climb up and access the nest.
  3. Hang Nest Boxes on a Wire: Instead of mounting the nest box on a pole or tree, you can hang it on a wire. The wire should be thin and flexible, so it’s difficult for squirrels to climb. To make it even more difficult for squirrels, you can add a squirrel baffle to the wire.
  4. Use a Squirrel-Proof Nest Box: Some nest boxes are designed to be squirrel-proof. These boxes have a small opening that only bluebirds can fit through, and they often have metal guards around the opening to prevent squirrels from chewing their way in.
  5. Distract the Squirrels: If you have a bird feeder in your backyard, you can try to distract the squirrels by placing a squirrel feeder away from the bluebird nest. This may help to divert their attention away from the bluebirds’ nest.

Overall, there are numerous proven strategies to deter squirrels from encroaching on bluebirds’ nests and eggs. By employing one or more of these strategies, you'll not only emerge as a protector for these enchanting creatures but also make a meaningful contribution towards a healthier, more balanced ecosystem.