A successful screech owl nest box (photo by Pete Ciula, Jr.).

It’s that time of year when if you hope to entice and benefit large cavity nesting birds – including some owls, kestrels, and some ducks – time is running short to install them in time for this spring’s nest box users. Whether you plan to add a big nest box to your property, at a nearby park or recreation area, a local nature center, refuge, or another option – time’s a tickin’! Who wouldn’t enjoy hosting a family of screech owls through the nesting season? Or a brood of Wood Ducks, or even the mini-falcons – American Kestrels.

Nothing can be more rewarding for birders, and nothing can benefit cavity nesting birds more than ensuring there are plenty of nesting sites available this spring. But keep in mind that there is a shortage of nesting cavities, with serious competition for existing cavity sites, so every new nest box can make a big difference this spring, and in future years.

Thanks to all the people who already provide nest boxes for cavity nesters of all sizes, and to anyone who doesn’t have a big nest box in place, consider making this the year to change that. But if you don’t have a property, or the right habitat, you may want to work with others on a cooperative project. Building or buying, and installing big nest boxes can be too much for one person to do, so getting involved in the big nest box action this spring may be a matter of organizing a group of helpers – friends in your neighborhood, a school or university group, an Audubon chapter, your birding buddies or bird club members.

It’s important to make a plan if you need to form a partnership, and an important part of that plan is where to install a new nest box – or boxes. If you have the will, equipment, and ample property, you can do it on your own, or at least make it a family affair. But you can also ask for the help of a local public or private entity to install a nest box in a local park with appropriate habitat, or a nature center, refuge, or preserve. Often, naturalists and property managers welcome such requests and you never know how enthused the people you contact may become. They may be inspired by your initial interest, especially if a first effort is successful and they enjoy the process; one nest box may lead to more in future years.

Positioning

Then too, the location you position a big nest box is as important as providing a nest box in the first place. The habitat available at a given location is especially important, as is the elevation of the nest box, along with other factors. First of all, what species are you trying to attract and benefit?

Wood Ducks and other cavity nesting ducks will require a suitable shallow wetland close by. Screech owls and other small owl species prefer a woodland edge, and American Kestrels prosper where a field or pasture meets an open wooded area. The owls and kestrels primarily feed on mice-sized rodents, although large insects like grasshoppers, crickets, and beetles are important too – so habitats that harbor such potential prey populations will benefit these big cavity nesters.

Size and Protection

The other considerations are to provide the right size of nest box for the species you wish to attract and benefit – both the size of the box and the size of the entrance. You don’t want the entrance to be so big that a potential predator can access eggs, nestlings, or even adults by reaching in, or actually crawling inside, as in the case of squirrels, chipmunks, rats, or snakes. You will also want to build or purchase nest boxes that have a hinged side, roof, or door to access the inside of the nest box – to clean and maintain the unit, to add wood chips to the floor, and to periodically monitor the nesting activities.

Of course, protecting any nest box from potential predators is paramount – otherwise you are just providing a feeding station for mammalian or reptilian predators. A proper nest box installation is needed; preferably a nest box securely affixed to a pole with a predator guard on the pole to keep raccoons, squirrels, chipmunks, snakes – even bears – from accessing the precious nest box contents.

One more important aspect of being a nest box landlord is to have a lot of patience, because birds may not occupy a nest box immediately. It may take a season or longer for birds to utilize your nest box, so be patient, keep up the good work, and appreciate that having an extra cavity site in an area is much better than not having enough. Good Luck!

The Ultimate Big Nest Box Consultant

For the best information about all the potential birds that might use a big nest box, along with the sizes of nest boxes and entrance holes for each species, habitat and installation information, along with predator proofing info, please consult the Cornell Lab of Ornithology’s Nest Watch where you will find several web pages that will serve you and inspire you.

Features of a Good Bird House provides a wealth of excellent information about nest boxes – big and small – at https://nestwatch.org/learn/all-about-birdhouses/features-of-a-good-birdhouse/

Positioning Nest Boxes – valuable information for each species at https://nestwatch.org/learn/all-about-birdhouses/nest-box-placement/ (scroll down to find the birds you are most interesting in).

Shop for a variety of Owl or Kestrel Nest Boxes at https://www.bestnest.com/bestnest/owl_houses.asp

You can Purchase a Duck Nest Box at https://www.bestnest.com/bestnest/duck_houses.asp and keep in mind that many duck, owl, and kestrel nest boxes are interchangeable.

Please also keep in mind that providing a nesting structure for a favorite species of bird is fun, as well as fulfilling, and sometime exhilarating. Take pride in your efforts to help benefit some of our most popular birds and enjoy the upcoming nesting season!