Many North American birds rely on tree cavities to raise their young — but natural nesting holes are disappearing. Learn which birds use nest boxes, why correct dimensions matter, and how one simple wooden box can support generations of songbirds. Includes a free printable nest box size chart.

Where should you hang a nest box? How big should the entrance hole be? Are gourds better than martin houses? Learn the essential nest box facts that help cavity-nesting birds stay safe and raise successful broods in your backyard

Purple Martins are the only North American songbird that now depends entirely on humans for nesting (with some groups in the southwest still nesting in natural cavities). Learn where they live, what habitat they need, how to set up proper housing, and why monitoring for predators and invasive species is essential to helping this remarkable bird survive and thrive.

Purple Martins now rely almost entirely on human-provided housing. Learn their habitat needs, house dimensions, and how to monitor and protect thriving colonies.