How to Stop Bigger Birds from Bullying Smaller Birds at the Birdhouse

May 29, 2025

Birds, blog

Here at Cetic Farm, we love our fine feathered friends. If you’ve ever set up birdhouses in your yard, you know how joyful it can be to watch feathered friends settle in, build nests, and raise their young. But what happens when larger birds start harassing the smaller ones and try to take over their homes?

In this post, we’ll explore how to protect small birds from bigger bullies, restore peace in your backyard habitat, and make sure every bird gets the home they need.

Understanding Birdhouse Bullying

When larger birds invade birdhouses meant for smaller species, it’s typically a matter of nesting competition. Aggressive birds will drive away smaller ones, sit on top of their houses, and even remove nesting materials. This behavior can be distressing to witness—but fortunately, you can intervene in a safe and effective way.

Most Common Backyard Bird Bullies

Identifying the birds is the first step. Here are a few usual suspects when it comes to aggressive behavior:

House Sparrows – Non-native and highly aggressive. They will take over nests, destroy eggs, and harass smaller birds like chickadees and wrens.

European Starlings – Another invasive species that aggressively seeks out nesting spots.

Tree Swallows – Not as aggressive as sparrows, but can still compete with smaller birds for housing.

Blue Jays – Can be territorial and intimidating, though they usually nest in trees rather than houses.

Entrance Hole Sizes for Common Birds

Choosing the right hole size for your birdhouse is crucial. Here are typical recommendations:

House Wren – 1 inch
Chickadee – 1 1/8 inch
Nuthatch – 1 1/4 inch
Tree Swallow – 1 1/2 inch
Eastern Bluebird – 1 1/2 inch
House Sparrow (avoid encouraging) – 1 5/8 inch or larger
European Starling (avoid encouraging) – 1 9/16 inch or larger
Downy Woodpecker – 1 1/4 inch

Keep in mind: smaller holes are better if you want to exclude larger or aggressive birds.

Master Gardener Tip

Install your birdhouses early in the season to give smaller birds first dibs before aggressive species arrive. Mount them on poles, not trees, to reduce predator and competitor access.

How to Protect Small Birds at Your Birdhouse

Install the Right Size Birdhouse Hole

Use a small entrance hole—ideally 1 1/8″—to accommodate chickadees, wrens, and nuthatches while keeping out most larger species like house sparrows and starlings.

Add More Birdhouses

Competition increases when there are limited nesting options. Add multiple birdhouses spaced at least 15 to 30 feet apart. Include a variety of hole sizes to attract both small and larger birds to their own designated spaces.

Relocate the Aggressive Bird’s House

If a larger bird has claimed a house, move it farther away—ideally to a different part of your yard. Distance helps reduce tension and gives each species its own territory.

Install a Predator Guard

A baffle or cone guard mounted above or below the pole will deter larger birds from perching on top of the house to intimidate the occupants. This also helps prevent snakes and raccoons.

Remove Nesting Materials (Only If Needed)

If a larger bird is raiding a house but hasn’t laid eggs, you can briefly remove nesting materials to discourage their return. Always check for eggs first—once eggs are laid, the nest is protected under the Migratory Bird Treaty Act (except for invasive species like house sparrows).

Can You Legally Remove Aggressive Birds?

Yes—house sparrows and European starlings are not protected under U.S. federal law. You can legally remove their nests (only when no eggs or chicks are present) and discourage them from nesting in your birdhouses.

Final Tips for a Peaceful Backyard Bird Habitat

Offer nesting materials like dried grass and feathers in separate areas
Keep bird feeders full, but space them out to reduce conflict
Add shrubs and trees to provide cover and alternate nesting options

By understanding bird behavior and adjusting your setup, you can create a welcoming space for both small and large birds—without letting bullies take over.