Birdhouses are mainly used for nesting purposes. If you wish to build functional birdhouses, find out the requirements for the species you want to attract. Functional birdhouses should be able to be cleaned yearly. There is a great difference in a functional and a decorative birdhouse. The National Audubon Society is a wonderful organization for the protection of birdlife.
Every year there are bird counts that anyone can get involved in.
The bird counts help us learn more about birds. For each species we can learn about their breeding habits, their migration routes, and about their habitat. To learn is to understand. To understand is to protect. Having a greater interest and understanding of birds will lead to a better interest and understanding of all wildlife.