Nest Box Provision for Cavity-Nesting Birds

Cavity-nesting birds — bluebirds, titmice, owls, bats — have lost critical nest sites as old trees decline, making nest box provision one of the most impactful garden wildlife welfare actions.

Key Facts

Approximately 85 bird species in North America nest in cavities — holes in trees or structures
Eastern bluebird populations recovered dramatically due to nest box provision campaigns
Great horned owls can be attracted with appropriately sized nest boxes in suburban areas
Nest boxes must be species-specific in size to be useful and to exclude competitors
Cleaning boxes annually between seasons prevents parasite buildup that harms chicks

Welfare Considerations

Cavity-nesting birds experience acute welfare benefits from appropriate nest box provision. Without nest sites, breeding is impossible and individuals may be reproductively excluded from populations. Bluebird trail programs — strings of boxes along rural areas — have contributed to major population recoveries. The key welfare considerations are species-appropriate design (hole diameter is critical), correct placement (height, aspect, distance from cover), and annual cleaning to prevent blowfly larvae from killing chicks. Monitoring boxes also allows data collection that benefits broader conservation.

What You Can Do

Install one or more species-appropriate nest boxes in your garden or on your land
Join your local bluebird trail monitoring network to maintain and monitor boxes
Clean nest boxes annually in late winter before breeding season begins
Share nest box plans with neighbors and community organizations to create networks
Donate nest boxes to schools and community gardens through local birding organizations