Nest Boxes

Questions and answers specific to nest-box monitoring.

The NestWatcher's Resource Center also has a lot of information on nest boxes.

Quick FAQ links - Scroll down for other common questions & answers

I was cleaning out my next boxes and I found a dead adult Tree Swallow in one of them. How can this happen? | What should I do if House Wrens nest in a box I put up for bluebirds? | What do I do with the nest after the birds have fledged? | Where can I find construction plans to build nest boxes?

I was cleaning out my next boxes and I found a dead adult Tree Swallow in one of them. How can this happen?

Many factors can affect avian mortality. Tree Swallows migrate quite a long way, some from Central America. If they arrive after such a long journey to wet, cold conditions, and a lack of insects (which is what they feed on), they may die. If you find dead young Tree Swallows in the box, make sure the inside wall of the entrance hole is roughly grooved so that the young birds have something to grip onto when fledging from the box.

What should I do if House Wrens nest in a box I put up for bluebirds?

House Wrens are commonly implicated in the puncturing of eggs of other cavity-nesting species. For this reason, some nest box landlords prefer not to play host to House Wrens. If you prefer not to attract House Wrens, make sure your nest boxes are far from shrubs or woods. The more open the site, the better. Please remember that it is illegal and unethical to disturb the nest or eggs of any native bird species, including House Wrens. The only species that are not protected by law are the non-native European Starling and House (English) Sparrow.

What do I do with the nest after the birds have fledged?

During the breeding season, you can leave the nesting material in the box – the parents may decide to raise another brood. At the end of the season, you can remove the nesting material and scrub the inside with a mild detergent and water. You can leave your box up over the winter and allow it to be used as a roosting place for birds, mice, or squirrels. Some monitors elect to seal off their birdhouses to prevent unwanted winter tenants. Some people render the boxes unusable by propping the door open. If your nest is soiled with fecal matter, we recommend removing the nest and cleaning the nest box out with a solution of 1 part bleach to 10 parts water.

Where can I find construction plans to build nest boxes?

A: In books. Your public library or local book store should have a few books on the subject of nest boxes. Here are two books with complete information related to nest boxes:

• Stokes, Donald and Lillian. Birdhouse book: the complete guide to attracting nesting birds. Broquet, LaPrairie, 1995. 96 p.
• Pennsylvania Wild Resource Conservation Fund & Pennsylvania Game Commission. Woodcrafting for Wildlife: Homes for Birds and Mammals.  3rd Edition. 64 p.

On the Internet. Many web sites provide information on nest boxes. We recommend our webpage where we have compiled some of the best information and links:

• The NestWatcher's Resource Center, by the Cornell Lab of Ornithology. You will find several different types of nest box models, box measurements for common species, species fact sheets, predator guard plans, etc.

Things to remember. If you want birds to nest successfully in your nest boxes, you should remember to:

• Protect the boxes from predators. Do not place them within easy reach of raccoons and squirrels.
• Clean them. In fall, once the nesting season is over, you should remove the old nest material. At the same time, it will eliminate parasites.