Snags provide "hawking" perches for flycatchers and resting perches for swallows. Flycatchers perch on a branch, fly out to snatch insects, and then return to the same branch to watch for other insects. Large natural cavities, formed in snags by decay, often provide homes for a variey of mammals including marten, porcupine, bats, bushy_tailed woodrats, northern flying squirrels, and other species. When left to decay and fall over naturally, large hollow snags may provide den sites for larger animals like mink, lynx, red fox, and wolverine. To help provide homes for this wide variety of animals, leave dead trees standing whenever possible, particularly snags larger than 6 inches in diameter and/or any containing woodpecker holes or other cavities.
Climate Safety: 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. Choose a bird house 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.