Bird nest box hole/protector

thingiverse

Smaller blue tits require smaller entrance holes to prevent larger great tits from driving them out. Meanwhile, great tits themselves face threats from woodpeckers and squirrels. To address these needs in one step, mount this protective ring in front of an existing hole. This ensures both the right size and protection are achieved. While birds may need to read Swedish signage to locate their nests, language barriers shouldn't be a concern since they frequently travel long distances.