Pondering Birdhouses with North Branch Land Trust

Have you ever noticed the abundance of birdhouses while hiking in Northeastern Pennsylvania? You’ll find them tucked in trees along trails, mounted on poles in open fields, even attached to barns or buildings in your neighborhood. At first glance, it might seem unnecessary, after all, aren’t there plenty of trees for birds to nest in, especially in wooded areas?

Surprisingly, many of these birdhouses serve a specific purpose: to support native cavity nesting birds like Eastern Bluebirds, House Wrens, and Tree Swallows. Usually, these species rely on natural cavities, such as abandoned woodpecker holes or dead tree trunks for nesting, since they cannot create their own nesting cavities. However, with more land being developed and dead trees often removed for safety or aesthetics, suitable nesting spots have become scarce. On top of that, invasive species like European Starlings and House Sparrows often outcompete the native birds for these limited spaces.

Even Better Birdwatching

The widespread installation of birdhouses has helped recover the Eastern Bluebird population in Pennsylvania. These installations also help encourage birdwatching opportunities in both rural and suburban areas. So don’t forget to grab your binoculars and a bird ID book and head outside to check out your local songbirds. You can also visit the PA Game Commission and Cornell Lab for a variety of tutorials and tips on how to make your very own bird boxes.

Birdhouses were originally installed on farms to attract birds to act as natural pest control. Over time, however, as humans evolved, so did the purpose of birdhouses. As farming practices declined, many fields were abandoned, resulting in the forests reclaiming those areas. Natural habitats for birds began to shrink. At the same time, urbanization and development spread, which further diminished natural nesting sites.

Adaptation and Survival

With that, many bird species that once relied on these natural habitats found themselves displaced. In response, birds began adapting to the changing environment. Rather than relying solely on natural cavities in trees, many birds began to seek out man-made structures as alternative nesting sites, taking up residence in unwanted places and sometimes becoming a bit of a nuisance.  Birdhouses came back and became a win-win for us and the birds. These structures were designed to provide the birds with safe, sheltered environments, protecting them from predators and the harsh weather conditions while keeping them from nesting in unwanted areas.

Small cavity nesting are not the only species that use man-made birdhouses

Other common species like the American Kestrel, a variety of owl species like the Barn Owl and the Screech Owl, and the Wood Duck call man-made bird boxes home. Each box is slightly different from the next, made and placed to meet the needs of the birds. For example, the Wood Duck nest would be placed facing water, where a Barn Owl nesting box can be placed on the side of a building. At North Branch Land Trust’s Hanover Crossing Marsh Sanctuary you can find our own duck boxes providing a protected nesting place for the Wood Duck. You can also visit Cornell Lab to learn all you need on how to build your own bird box and customize it to what species you would like to attract and protect.

Help keep birdhouses clean and safe

Keep note that if you notice that a birdhouse needs maintenance or repairs feel free to contact the landowner, as it’s important to ensure that these structures remain safe and functional. Otherwise try to avoid disturbing the nests, all you need to do is grab your binoculars and sit back and enjoy their presence. As for keeping your own birdhouses safe and functional, remember to clean out old nesting material between seasons to prevent harboring disease-spreading bacteria. This also goes for maintaining bird feeders and bird baths too.

Learn about how North Branch Land Trust conserves habitat and more at nblt.org