Many birders enjoy having birdhouses in their backyard to watch bird families as eggs are laid, chicks are hatched and fledglings are raised. It can be devastating when tragedy befalls those feathered families, and hazards can come in many forms. Predators, poor climate, and illness are just a few threats can all take a toll on backyard bird populations. These 12 tips for safer birdhouse designs can help turn the odds in favor of nesting birds’ survival by minimizing the greatest risks.
Backyard predators that threaten birdhouses can include pets, stray cats, raccoons, rats, squirrels, snakes, mice, and stinging insects. Other bird species may also kill or injure baby birds and their parents either for a meal or to take over the house for their own nesting site. To make a birdhouse safe from predators follow these tips:
- Remove any perches from the house. Birds do not need them to access the house, and perches only provide convenient handholds for predators. At the same time, remove any nearby branches that could also provide a way for predators to access the house.
- Train outdoor pets to keep away from birdhouses. Behavioral conditioning with a water hose is an effective method that can also be used on squirrels and other wildlife with enough patience and perseverance. Pets should be supervised when outdoors during the nesting season especially since young birds leave their nest several days before they can fly, making them easy targets for curious pets.
- Be sure the birdhouse opening is the right size for the species you wish to attract. If the opening is too large, predators will have easy access to the nest and other bird species may take over. A very large opening may also be dangerous for growing chicks, which could tumble out of the hole. A small hole could cause birds to get stuck, or they won't use the house at all.
- Position the birdhouse far enough away from any brush so predators cannot stage an ambush, but close enough to plants so parent birds can easily scout the area. Five to eight feet of distance is sufficient for most birdhouses. Similarly, keep bird houses away from popular feeding areas to prevent territorial conflicts between feeding birds and nesting parents.
- Choose natural colors so the birdhouse will blend into the surroundings. Browns and dark shades of green are the most suitable choices and will be the most attractive to birds. If desired, decorate the house with natural materials to keep it concealed but still an ornamental focal point in the yard.
A safe birdhouse is snug and comfortable for nesting birds, without being subject to extreme heat or cold, rainy leaks or damaging winds. To keep a house safe from the weather follow these tips:
- Choose a birdhouse design with ventilation holes in the upper part of the walls to circulate fresh air and prevent the house from getting too hot and suffocating or stifling chicks. If the design does not include ventilation holes, drill unobtrusive holes in the corners or sides of the house. Do not drill holes in the roof, however, where leaks could occur.
- Position the house so its opening does not face into direct sunlight or prevailing winds. Full or partial shade will help keep the house cooler, and a more protected location will be safer. If necessary, a longer overhang above the entrance can also help provide shade and shelter.
- Angle the house so rain cannot easily run into the opening or through ventilation holes. Some birdhouse models include an angled face to ease water runoff, and a larger roof overhang can also help keep the interior of the house dry. The house could also be positioned in a more sheltered area, such as underneath the eaves of a roof or against the trunk of a large, full tree that will help protect the birdhouse.
- Avoid birdhouses made of metal. Metal houses will become miniature ovens in the summer heat, and reflective metals are highly visible to predators. The house can have metal guards or trim over a different material, such as a metal cover to fix an entrance hole to the proper size if needed.\
Birdhouses can become crowded as nestlings grow, giving diseases and mites greater opportunities to spread to young birds. A safe birdhouse is one that takes into account the health of the birds, following these tips:
- While it is okay to paint the outside of a birdhouse, do not paint the interior surfaces or the inner rim of the entrance hole.
Use only environmentally safe paints, stains or varnishes on the outside and avoid any lead-based paints that can poison birds from fumes or ingestion.
- Choose a birdhouse design with the proper interior dimensions for the desired residents. Too small of a house may cause growing birds to smother, while too large of a house will not be attractive to nesting parents. Smaller birds could also become too chilled in a larger house if they are not huddled together when needed.
- Clean the house seasonally or whenever a family of birds vacates the premises. Remove all nesting debris and rinse the house with a sanitizing solution of one part bleach and nine parts water. Rinse the house again with clear water, and allow it to air dry thoroughly before storing it for the winter or repositioning it for new tenants.