Since most cavities are excavated in dead, dying or diseased trees with soft interiors, there is a shortage of habitat supporting cavity nesters in towns and cities where foliage are groomed and dead trees are considered unsightly.  Many bird species we might expect to find only in forests or open country are found in cities.   Since birds have that unique ability to fly, they appear suddenly in areas where they were previously absent.  The right bird house design in the right area can attract a bird pair to nest.

Some birds that do not migrate south in cold weather look for boxes to roost in.  Woodpeckers normally chip out new cavities for winter and they may roost in boxes. 

Build wooden birdhouses with ventilation, water drainage, a means to mount securely, and access to the interior for cleaning.  Investigate species intrinsic to your area and nestbox dimensions intended for those specific species.

Some prefer decorative birdhouses and painted birdhouses.  Try painting 50birds birdhouse designs.  Print free woodworking plans for 50birds Platform and Birdhouse Plans in the Models Index.
 

A few birds that nest in trees, stumps, bushes or rock ledges will nest on platforms.  Robins nest on door and window mantels.  Phoebes and Barn Swallows nest in open sheds.  Cliff Swallows nest under bridges and building eaves.   Peregrine Falcons will nest on tall building ledges.

Robins are probably the most easily attracted birds to a platform.   Phoebes like platforms.  Blue Jays and Mourning Doves that normally nest in trees will nest on platforms.  Song Sparrows, Catbirds and Brown Thrashers will nest on platforms placed in shrubbery.  Carolina Wrens and House Finches nest in either boxes or platforms. Barn Swallows and Cliff Swallows occasionally take advantage of a ledge placed in the right spot.  King Birds will sometimes nest on posts.  Great Horned Owls, Red Tailed Hawks, and Osprey will nest on large heavy-duty platforms mounted high in the right places.

See Bird Species Which Nest On Platforms  and  Platforms

When mounting a wooden bird house, in addition to placement for a specific species, consider accessibility for convenience and safety when monitoring and cleaning.   Be sure houses are securely mounted.

Don't crowd a yard with nestboxes.  Wrens may build nests in several boxes before selecting one, but too many boxes may deter other birds.  Bluebird nest boxes should be about 100 yards apart although swallow boxes can be placed within 10 yards of the bluebird boxes and make good neighbors as they are less intimidated by sparrows.

Woodpeckers, Chickadees and Owls do not migrate south in winter and may use nestboxes in winter.  Mounting in the fall or winter will give the box a chance to weather before spring.  Place 1 or 2 inches of dry wood chips in the boxes intended for Woodpeckers, Chickadees and Owls.  Sawdust will not ventilate and dehydrate as well as chips and chips are easier for birds to rearrange or pack in and out.   Fill a box intended for a Flicker.  They will excavate the chips.

Monitor your bird houses being careful not to disturb during nest building, incubation or brood rearing.  If you observe regularly and everything seems ok, if birds are gathering nest materials, or feeding their young and can hear the hungry young birds calling for more food, there is really no reason to open nest boxes.

Make sure there isn't something in them other than intended.   Nestboxes also attract squirrels, mice, snakes, insects and unwanted birds like house sparrows or starlings. Make sure desired birds aren't being driven away.  If they are being intimidated by more aggressive bird species, it's a sign they are in peril.   Nothing is more disgusting than finding a family of dead bluebirds, adults and babies, around a nest box.  Sparrows move into homes with 1 1/2" or larger openings and starlings will use anything larger than 1 1/2".

There is debate whether one species should be favored over another.   We know not to interfere with natural selection, but Sparrows and Starlings are not native.  Since they were introduced their populations increased to unnatural numbers displacing native species.  They are agricultural pests spreading parasites and disease and they defile buildings in towns and cities throughout most of North America.   They are not protected by law as are other migratory birds.  Destroyed habitat, over hunting and non-native species reduced natural populations.  Now, proper management is a reasonable intervention, even imperative to ensure survival of the most easily stressed species.

Bird feeders create a pleasant atmosphere full of foraging and singing birds.  Constant feeding is their sole source of energy and warmth.  In Winter, shortages of seeds, berries, and insects, particularly during severe weather, make foraging especially difficult.

Sunflower seeds are a premium feed.  They are a high energy and nutritious food source and leave less waste than some other seeds.  House Finches, Purple Finches, Chickadees, Titmice, Nuthatches, Woodpeckers, Doves, Goldfinches, Grosbeaks, Cardinals, Buntings, and Bluejays eat sunflower seeds.

Suet (animal fat) is another nutritious food, which attracts Chickadees, Woodpeckers, Titmice and Nuthatches.  Most birds will eat some suet.  See Feeding Birds and Bird/Fruit Chart

Used nests are often tainted with fleas, mites, and lice waiting for more inhabitants.  Feeders can spread parasites and disease.  Remove nests after rearing and clean and spray nestboxes and feeders with a mix of 90% water and 10% chlorine bleach. Replace wood chips in nestboxes for ducks, woodpeckers and chickadees.  Clean feeders regularly and provide more than one if large numbers feed to reduce close contact.  Smaller birds will be bullied less.  Make sure seed is dry and free from mold.  Store seed where mice cannot contaminate it with droppings, parasites and disease.  Bird Baths absolutely must be cleaned regularly.  If they are not cleaned, it would be better not to have one at all.