This is the time of the year to get some nesting boxes prepared for our feathered friends. Bluebirds, wood ducks, kestrels, martins, screech owls and tree swallows will use man-made nesting boxes.
Why provide nesting structures? What did these birds do before humans started building bird boxes? Well, we have lost a lot of old, hollow trees which provide nesting cavities not only for birds but also animals such as raccoons and squirrels. There are also more non-native birds now, such as starlings and house sparrows, that compete for these nesting cavities. Loss of nesting places, along with loss of habitat, has caused a decline of certain birds. The starling and house sparrow drove away bluebirds from nesting cavities. Newer farm practices, such as huge crop fields with no hedgerows, fewer grasslands, and the use of pesticides caused an all-time low in the bluebird population in the late 1970s. However they began to rebound in the 1980s with the bluebird conservation movement that motivated people to erect nesting boxes.
Of course there is more than just building a box and putting it up somewhere. First, we need to build the right size box with the proper entrance hole. You can find information on building nesting boxes at the library or on your computer.
Winter is a great time to build these boxes because they need to be in place early in the spring. Some birds, such as wood ducks, return very early and begin looking for places to nest. Others, such as bluebirds, actually use these boxes for roosting in the winter.
Each of the birds I mentioned has a preferred location, nest height and nesting material. They also need some kind of predator guard to keep raccoon, cats, squirrels and now fishers from getting to the boxes.
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Let’s start with our beautiful New York State bird: the bluebird. They like short grassland locations such as pastures, large lawns and golf courses. Try to stay 30 or 40 yards away from bushy areas that will attract house wrens, which will destroy bluebird eggs. It will also help to face the boxes away from these areas. If you place boxes in a pasture make sure the farm animals cannot rub against them.
Bluebirds prefer a low box height such as 4 or 5 feet. The best mounting post is 3/4-inch or double-walled 1/2-inch electric conduct pipe as it is hard for a predator to climb. Another way to deter predators is to put grease on the pipe. The practice of putting a piece of PCV pipe over a stake usually doesn’t work, as it is big enough to give a raccoon a “hugging” type grip to climb. If a bluebird trail (a series of boxes) is to be set up they need to be a minimum of 100 yards apart. No nesting material is needed inside; bluebirds bring their own.
The tree swallow will also use a bluebird box. They are a great bird to have around as they eat a lot of flying insects.
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The wood duck population decline years ago was due partly to the lack of hollow trees. With the development of nesting boxes and proper management, wood ducks are common waterfowl in local marshes again. Wood ducks require larger nesting boxes and they should be placed near a body of water, although these ducks will use boxes up to 1-1/2 miles from water.
The “woodie” is a shy duck so don’t place the boxes too close to human disturbance. They can be mounted on top of steel poles, 4×4 wooden posts, or on trees. Boxes over water only need to be 4 or 5 feet above the high water level; on land, 6 to 10 feet is fine. The important thing here is to place a predator guard below the box to keep raccoons and the like from climbing up and killing the nesting hen. If you place a nesting box on a tree make sure a predator can’t get to it by climbing from another tree. If you don’t put up guards, then don’t put up a box, you will only be getting a bird killed.
For nesting material put 4 to 6 inches of wood shavings in the box. Your local farm or pet store will carry it. Do not use sawdust as that holds moisture and can suffocate the young ducklings.
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Another important aspect of having bird nesting boxes is maintenance. Clean out the boxes every year after nesting season and put fresh wood shavings in (where needed) before the birds return in the spring.
Keeping house sparrows, starlings and house wrens out of these boxes can be a constant job but it is necessary if you want your desired birds to be successful. Watching birds raising a family in a nesting box can be very enjoyable and educational but it does require some work.