History
American Indians are credited with starting the U.S. birdhouse tradition at an unknown date by using gourds for nest boxes, but in Turkey, birdhouses date to at least the 15th century.  An American ornithologist in the mid-19th century wrote about Choctaw Indians stripping the top branches from a sapling and hanging gourds from the stripped branches. Indians hung dried hard-shell gourds as birdhouses, even setting up poles and crossbars for the gourds, according to ornithologist Edward Forbush in 1929.  When the gourd-hanging started is anyone's guess but presumably after observant Indians learned how to attract the martins, which normally nested in cavities created by other species.  Since the purple martins consume large numbers of flying insects, the mosquito population could be kept in check. Purple martins' alarm calls would warn of predators.

Eventually many European settlers adopted the birdhouse tradition, often for the same reasons.

After countless bird generations, the martins adapted to the gourds and left cavity-dwelling behind. As many actions have, there were long-term unintended consequences, what is called a behavior tradition shift.

Houses near homes

Eastern purple martins now depend totally on human-provided birdhouses for their survival, preferably within 100 feet of a residence. For some reason, the western martins don't all use birdhouses.

Beginning in the 1970s, efforts were made to build birdhouses, and 10-15 years later, the population stabilized; 35 to 40 nesting pairs were in the Olympia-Shelton area; in 2002, more than 40 pairs were in nest boxes in Everett, Tulalip and Camano Island.  

Eventually birdhouses for many species moved beyond the traditional gourd (except for those who made gourd painting a folk art). Given the artistic license that builders used in the 20th century and into the 21st, it became clear that while birds don't need birdhouses, people do.

Otherwise they wouldn't build birdhouses in the shapes of an acorn, 6-foot-tall mansions, pair of dice, lighthouse, human head, castle, gingerbread cottage, triple-decker pagoda or domed tent.  History provided by Sharon Wootton

Types of feeders

Seed Feeders are the most common type. These can vary in design from tubes to hoppers and trays. Sunflower seed or mixed seed are popular for use in these feeders and will attract many songbirds such as cardinals, finches, and chickadees. Black-Oil Sunflower seed is especially popular with bird enthusiasts. The outer shell of Black Oil Sunflower seeds are thin and easy to crack. In addition, the kernel is larger than striped or white sunflower seeds. Most bird structures are designed to dispense sunflower-sized foods, but there are specialty "Finch Feeders" with smaller openings to dispense the tiny Guizotia abyssinica (Niger or nyjer) type of thistle seed, which is a favorite of smaller finches. Goldfinches are especially attracted to nyjer seed.

Hummingbird feeders, rather than dispensing seed, supply liquid nourishment to hummingbirds in the form of a sugar solution. This mixture often is colored red to attract birds. Some Hummingbird feeders have red accents or red glass to help attract hummingbirds. Mold tends to grow in hummingbird feeders, so they must be refreshed frequently and kept very clean to avoid harm to the birds. Ants and other insects are also attracted to hummingbird nectar.  Smearing petroleum jelly on the feeder's hangar will prevent the ants from crawling down to the feeder below.

Oriole birdfeeders, which are traditionally colored orange, also supply such artificial nectar and are designed to serve New World orioles, which have an unusually shaped beak and tongue. These orioles and some other birds also will come to fruit foods, such as grape jelly, or half an orange on a peg.

A suet feeder is typically a metal cage-like construction with a plastic coating that contains a cake or block of suet to feed woodpeckers, flickers, nuthatches, and many other species of insect eaters. Suet logs are also very common. These wooden logs have holes drilled out for suet to be inserted. Suet is high in fat which helps to keep birds warm and nourished during the cold winter.

Providing a varied array of tastes and feeding venues will result in less competition for food and dining spots, just as a well-planned garden will provide many plants that supply different types of seeds and nectar. A very shallow, gradually deepening birdbath that is safe from cats, kept clean, and refreshed frequently with clean water to avoid mosquitoes can attract as many birds as a birdfeeder. Although a clear area around it that is free of hiding locations for cats should be provided, the birdbath should be placed where a frightened bird can fly up easily to an overhanging limb or resting place if disturbed or attacked.

Squirrels may also help themselves to the contents of bird feeders, often not merely feeding, but carrying away the food to their hoard. There are various anti-squirrel devices available to thwart attempts by squirrels to raid bird feeders. Several manufacturers produce feeders with perches that collapse under the weight of anything heavier than a bird, or that use battery power to shock an intruder lightly or spin the perching area to fling it off. Caged feeders are often designed so that squirrels cannot reach the seed inside, but birds can easily fly through the cage's holes. Another way to keeping squirrels from getting into the bird feeder is to add crushed red pepper flakes to the seed; birds lack the receptor to which capsaicin binds, so it does not function as an irritant for birds.

The placement of a bird feeder can also prevent squirrels from accessing the seed. In addition, baffles can be used that prevent squirrels from gaining their footing above feeders. Below feeders, baffles can prevent squirrels from climbing any further.

Sometimes the placement of a separate and isolated squirrel feeder is the best way to keep squirrels away from bird feeders. Squirrel feeders typically offer a whole dried cob of corn, often at the top of a rotating stick to add a bit of amusement to their antics.

Seasonal Use

While bird feeders are thought of by some as winter projects, urban and some suburban areas can benefit from birdfeeders year-round. Winter feeders can be used during severe weather to provide food for birds who are caught in a snowstorm and find natural food with greater difficulty.

Portions of this article are from Wikipedia