When starting out housing bluebirds, you obviously need a bluebird nest box and somewhere to mount it. But as you research and see different setups, you might notice baffles. Are baffles really that important for bluebird houses? And if they are, what type of baffle do you need?
Baffles are vital for bluebird houses and bird protection because bluebirds and other native cavity birds are especially vulnerable to predators. Being in a box automatically traps them inside when predators reach in, and with some native cavity birds in decline, good stewardship is required.
The Importance of Escape (Cavity nesting birds vs. open nesting birds)
Before diving into baffles and nest boxes, it’s important to make a distinction between open nesters and cavity nesters.
Open nesters are birds who nest in the open, usually in a tidy cup on a tree or under the eave of a home. They include common native birds like the Northern Cardinal and the American Robin.
Cavity nesters are birds that nest in nest boxes, birdhouses or tree holes. These include your bluebirds, chickadees, woodpeckers, and purple martins to name a few.
Open nesters have more options to escape when a predator threatens the nest. While a mother may lose her babies or eggs, she doesn’t lose her own life. And a reproductive female bird is ecologically important. She can go on to lay a new clutch.
However, cavity species do not have the option of escape from inside the nest box. There is no 360 degree direction of escape. There is no z-axis where they could fly up or down. There is only one way in and out of the nest, and that is through the entry/exit hole. Once a snake enters its head, or a racoon reaches in, the escape route is blocked.
So while it would seem that a nest box offers a lot of protection and shelter, it is actually dangerous from a predator standpoint.
Learn more about bluebird predators here.
It’s important to note that there is a 2-hole nest box design. It has a second hole to help with escape. However, a raccoon can easily reach both arms in. And the 2-holes face the same direction, making predator escape very hard.
What Kind of Baffle Do you Use for Bluebirds?
There are a lot of different baffle styles out there. The one a lot of us are familiar with are cone-shaped baffles.
But when it comes to protecting chickadees, bluebirds and other native cavity nesting birds, a stovepipe baffle is the best choice, the bigger, the better.
A stovepipe baffle (Kingston Guard/Baffle) is a cylinder shaped baffle that is placed on a pole underneath the bluebird nest box.
We have an article that goes into more detail about the best baffle to use for bluebirds, but we can sum up what you need here, and then you can check it out if you want more information.
The most versatile, most protective stovepipe baffle option is one that is 8 inches in diameter by 60 inches tall. However, this option is not commercially available.
Another problem with a 60 inch tall baffle is accessibility. In order to have a baffle this tall, you have to have your nest box mounted on a pole that is at least 6 feet tall (off the ground). This ensures the baffle can wobble and it is set slightly under the nest box. But at 6 feet, some of us would need a step-ladder to access the box for monitoring. This isn’t always an option or safe for everyone. And you need to choose an option that is safe.
The next best choice that is commercially available, and still offers a decent amount of protection is a stovepipe baffle that is 8 inches in diameter by 24 inches tall (or taller).
We actually carry the 8×24 inch baffle and use it extensively on our bluebird trails.
The stovepipe baffle (both 8×24 and 8×60 inch) has been tested across several bluebird trails. These bluebird trails usually host different native cavity species like tree swallows, chickadees and house wrens along with bluebirds. Time and time again, a wide and tall stovepipe baffle has been one of the most effective methods of predator protection. Studies have also shown that pairing this with another form of predator protection such as a Noel Guard can be even more effective.
The benefit of the taller, 60 inch baffle is that it does offer better protection against longer black rat snakes that can invade nest boxes. A baffle that is 24 inches tall can still offer protection from snakes, but usually at a max of snakes that are 2.5-3 feet long.
One thing to note is that cats are very good jumpers and are very persistent. They have gotten past a 60 inch baffle. But, there is another solution to help predator-proof your bluebird nest box, and it doesn’t cost that much.
How to make your baffle more effective
Your baffle is not going to work if it isn’t set up right.
To make sure your bluebird baffle is effective, you need to mount it on a pole, and ensure it can wobble (like a reverse bell). Set it 6-12 inches under your nest box, but don’t let it touch the ground.
Another way to optimize your baffle is to add a little duct tape under the mounting bracket. The mounting bracket is a small object that screws around the pole. You then slide your stovepipe baffle over the pole and let it sit on the bracket.
But when storms are heavy and the wind picks up, the mounting bracket can slide down the pole. A little bit of duct tape wrapped around the pole right underneath minimizes the risk of slippage.
Lastly, never ever add grease to your pole! Grease gets on bird feathers, and rehabbers regularly end up with birds in their care as a result.
Where to find a proper bluebird baffle
The 8″ x 24″ baffle is one of Nest Hollow’s most popular products. You can order from us or find them at your local bird shop.
For a taller baffle, you would need to make this. These are made using 60 inch Duct Pipe from your local hardware store. This will require some special tools as well. There is a great YouTube video tutorial on how to make this type of baffle, and they don’t cost a whole lot.
