Birdhouses require monitoring on a weekly basis after being set-up. There are bound to be problems with parasites or losses due to predators. This is why it is very important to choose a birdhouse that would allow regular monitoring and cleaning.
There are two bird species that should be given particular attention to when found in the prepared birdhouses. These are the European Starling and the House Sparrows which are very aggressive species introduced in the American landscape in the 1800’s. Their presence can be very exasperating for those seeking to attract native species to birdhouses. They have managed to spread to practically every corner of the country and have out-competed native birds for food and nesting cavities. They evict and kill native species and build their nest on top of the previous nest.
Due to this behavior, they have been considered pest species and are sought to be controlled by traps, shooting and regular removal of their nests. They can be eliminated through persistent harassment. This is allowed as they are not protected by law governing species. It is considered illegal to capture, hold, transport or kill any protected specie and to take or destroy its eggs or nests, including long abandoned nests. It is likewise illegal to possess any live bird, including sick or injured ones. Neither is it allowed to possess a dead bird including feathers or other parts of the bird. It should be noted that any relaxation on the war against Starlings and Sparrows will quickly result to reestablishment.
Birdhouses that have been used by them should be completely cleaned out. Starlings can be effectively prevented from nesting by keeping the hole diameter large enough only for the desired specie. Trapping House Sparrows is the best method to eliminate them. Martin houses should be plugged in winter time or House Sparrows and Starlings will take up residence.
Cleaning of birdhouses should be done once a year at a minimum. The best time would be after the birds have finished breeding. The old nesting material should be removed and the house scrubbed with a solution of one part bleach to nine parts water. The inside part should be rinsed well and be allowed to dry completely before closing up. Thorough look over of the house should be done to make sure that the hardware is still firmly in place and the panels are not falling apart.
For birds that are multiple brooded or those that typically raise more than one family in one season such as Wrens and Bluebirds, it is not necessary to clean out the box as soon as the young have fledged. It is recommended however to clean out the nesting materials between broods to reduce nest parasites. Most birds will not use a nest a second time but build on top of the existing nest or do some rearranging when they decide to. Bluebird and chickadee boxes can be left open during winter as they use these boxes for roosting.
Good quality birdhouses are built for easy cleaning by having hinges, slide-out bottoms or any other means. A unit that need not be totally disassembled for cleaning is highly preferable. Birdhouses that have been cleaned out can be put back in place for the use of non-migratory birds as shelter during winter.