Birdhouses provide vital shelter for many species of birds. However, they also attract unwanted attention from predators looking for an easy meal. Protecting birdhouses from predators takes some planning and effort, but it is absolutely worth it to keep nesting birds safe. There are several effective techniques to deter predators and prevent them from accessing nesting birds and eggs inside birdhouses.
Use Predator Guards and Baffles
Installing predator guards or baffles on the pole or tree where a birdhouse is mounted can block climbing predators. Baffles are cone-shaped or cylindrical barriers that surround the pole and prevent animals from climbing up. Make sure baffles are wide enough that predators cannot reach around or jump over them. For smaller birdhouses, metal predator guards that fully enclose the mounting pole also work well. Position guards and baffles at least 2-3 feet off the ground to stop most predators. Raccoons in particular are excellent climbers, so the higher, the better.
Some key tips when using predator guards and baffles:
- Choose smooth, slick metal or plastic for surfaces. Avoid wood or materials predators can grip.
- Regularly check for damage and repair any compromised sections immediately.
- Clear any vegetation or branches touching the baffle/guard so there are no alternate access points.
- Reapply slippery lubricants periodically to metal surfaces if needed.
Predator guards and baffles may not fully deter the most agile or determined predators. But they form an excellent first line of defense and make accessing birdhouses much more difficult.
Mount Birdhouses in Safe Locations
In addition to predator deterrent devices, positioning the birdhouse itself in a safe spot is key. Mounting options like a metal pole make it harder for predators to get a foothold. Also consider:
Place Birdhouses Over Water
Mounting a birdhouse on a pole surrounded by water creates a moat predators cannot cross. The pole should be tall and sturdy enough that predators cannot reach the house from the water’s edge or by jumping. This is a great option for properties with ponds or other water features. Make sure the house itself is safely out of the water’s reach during fluctuations in water level.
Use Slippery Poles
Metal poles with ultra-slick surfaces prevent climbing. Aluminum or galvanized steel works well. For extra slipperiness, coat the pole in lubricant like heavy grease or motor oil regularly. A tilted pole leaning outward also makes climbing nearly impossible.
Put Birdhouses in Open Areas
Locate birdhouses away from vegetation, fences and structures. Open areas give birds a clear view of approaching predators. It also eliminates places for predators to hide and climb up from. Open placement can make it harder for homeowners to access for cleaning – install pulley systems if needed.
Mount Birdhouses on High Points
Place houses on tops of poles or trees. Keep them as far from launching points like low branches as possible. The greater the distance and difficulty for predators to reach a house, the better protected it is.
Think carefully about positioning. Observe where local predators travel through the yard and mount houses well out of their path and access capabilities.
Choose the Right Entrance Hole Size
Another line of defense is to make the entrance hole itself too small for predators to enter. Hole dimensions should follow the “goldilocks rule” – not too big, not too small, but just right. An oversized opening lets in predators while holes too tiny prevent nesting birds from entering.
Follow these guidelines:
- Measure nesting birds and add no more than 1/2 inch total beyond their body width
- 1 – 1 1/8 inches is ideal for many chickadee or nuthatch-sized birds
- Larger species like bluebirds need 1 1/2 inch holes
- Oval or rectangular slots work too, sized to bird proportions
- Perches should also suit the species; smaller birds prefer flush entrances without perches
With careful hole sizing, birds can freely enter and exit while excluding predators and larger species that may compete for nest sites or prey on eggs/chicks.
Clean Out Old Nests
Another predatory animal deterrent is to empty out old nesting materials annually after birds fledge and leave the nest. Remnants can contain smells that attract attention. And a pile of nesting debris makes it easy for predators to climb up and access the interior.
Follow these nest cleaning tips:
- Wait until well after baby birds have left the nest before cleaning
- Remove all old nest material, feathers, droppings and debris
- Check interior dimensions and make any needed repairs
- Wash the house and mounting pole with soap and water if needed
- Replace nest box lining like wood shavings if desired
A fresh, empty birdhouse is much less enticing to predators looking for signs of nesting activity and easy access.
Use Nocturnal Predator Guards
For predators active at night like raccoons and owls, extra efforts may be needed. Nocturnal guards physically block the entrance at night then reopen in the morning once danger has passed. Guards should be sized so adult birds can push through them when exiting the box.
Pivot Door Predator Guards
These devices use a hinge or pivot system at the entrance. The bird’s weight triggers the door to swing open when exiting. It then snaps securely closed against nocturnal intruders. Pivot guards are easy to install and adjust on many birdhouses.
Magnetically Controlled Predator Guards
A photo-sensor system on these guards detects daylight and engages a magnet lining the entrance. After dusk, the magnet turns off and a spring pulls the door shut. They re-open at dawn. Solar power often runs the sensor. Guards with manual switches are also available.
Light-Sensor Predator Guards
Similar to magnetic guards, these systems use light sensitivity to control the door. A photoresistor detects darkness and closes the hatch, securing the nest at night when birds are most vulnerable.
Nocturnal guards provide important overnight protection but they can be tricky to calibrate and maintain. Make sure the entrance size and mechanism still allows smooth passage for nesting adults.
Use Multiple Strategies
A combination of techniques is best to foil predators. Baffles, proper pole and birdhouse positioning, entrance hole sizes and nocturnal guards working together create multiple barriers for predators. Think in terms of layers of protection to make getting into nesting boxes as difficult as possible.
Dedicate time to carefully observe backyard predators, climb capabilities and habits. Tailor deterrents to the common intruders in your specific area. Routinely check and maintain all predator blockers. A diligent, proactive approach is the best way to safeguard bird families successfully raising their young in your birdhouses.
Frequently Asked Questions About Protecting Birdhouses from Predators
Protecting backyard birdhouses from predators takes some work but yields huge benefits for nesting birds. Here are answers to some common questions about deterring animals that threaten birdhouses:
What are the most common birdhouse predators I should watch out for?
Raccoons, snakes, domestic cats, squirrels, mice, and owl are some of the most frequent birdhouse predators. Raccoons in particular have very nimble paws and climb well, making them adept nest raiders. Cats also stalk and hunt adult birds coming and going from houses.
What is the best pole material to mount a birdhouse on to prevent climbing?
Slick metal poles like galvanized steel or aluminum work very well to prevent climbing by predators. Try to use a smooth surface with no texture or footing for animals to grip. Also use lubricants like heavy grease or motor oil on the pole surface.
How often should I check predator deterrents like baffles?
Check climbing deterrents at a minimum once per week during nesting season. Look for any damage, sagging, bending or holes predators could exploit as access points. Especially examine baffles and guards right after storms. Make any needed repairs immediately to prevent compromising bird safety.
What is the ideal birdhouse entrance size to keep out predators?
The entrance hole should be just large enough for the nesting bird species to pass through, plus no more than 1/2 inch extra. For small birds like chickadees, aim for 1 to 1 1/8 inch diameters. Larger species need holes around 1 1/2 inches. Oval slots work too.
How can I stop raccoons from climbing my birdhouse pole?
Raccoons are extremely adept climbers, making them a formidable nest predator. Use extra tall and slippery steel poles, lubricants like heavy grease, and very wide predator baffles (at least 18 inches) to deter them best. Place baffles high up the pole, 5 feet or more off the ground if possible.
Is it okay to handle or disturb birdhouses that have active nests?
Never tamper with an active nest containing eggs or baby birds – this is illegal in the U.S. under the Migratory Bird Treaty Act. Wait until the nest is empty and fledglings have left the box before doing any monitoring, cleaning or repairs on the birdhouse.
How often should I empty out old nesting materials from birdhouses?
Plan to clean out any old nesting debris annually after baby birds have successfully fledged and left the nest for the season. Be sure to remove all traces of old nest material, feathers and droppings which could attract predators.
Conclusion
Protecting nesting birds from predators takes vigilance and work, but it is a very rewarding endeavor. When you take proactive steps to deter climbers, block entrances and monitor birdhouses regularly, you create vital safe nesting sites. Additionally:
- Observe backyard habits of predators and be flexible with deterrent methods
- Maintain any guards, baffles and nest boxes routinely
- Use a combination of strategies like placement, slippery poles, and entrance guards
- Customize entrance sizes to exclude predators but allow adult birds passage
With some knowledge and commitment, you can successfully safeguard precious eggs and baby birds in your backyard birdhouses. The satisfaction of seeing fledglings finally stretch their wings thanks to a well-protected nest is well worth the effort.
So inspect your birdhouses and install predator deterrents before nesting season begins. A few simple improvements could save many birds from becoming easy prey this year and for years to come. The birds will thank you!