A birdfeeder, bird feeder, bird table, or tray feeder are devices placed outdoors to supply bird food to birds (bird feeding). The success of a bird feeder in attracting birds depends upon its placement and the kinds of foods offered, as different species have different preferences.
Most bird feeders supply seeds or bird food, such as millet, sunflower (oil and striped), safflower, Niger seed, and rapeseed or canola seed to seed-eating birds.
Bird feeders often are used for birdwatching and many people keep webcams trained on feeders where birds often congregate some even live just near the bird feeder.
Seed feeders are the most common type of feeders. They can vary in design from tubes to hoppers and trays. Sunflower seeds or mixed seeds are popular for use in these feeders and will attract many songbirds such as cardinals, finches, and chickadees. Black oil sunflower seeds are especially popular with bird enthusiasts. The outer shell of the black oil sunflower seeds are thinner and easier to crack than other types of sunflower seeds. In addition, the kernel is larger than the striped or white sunflower seeds. Black Oil Sunflower seeds also contain a large amount of fat; therefore they are especially good to use in the winter. Most bird feeders are designed to dispense sunflower-sized foods, but there are specialty "finch feeders" with smaller openings to dispense the tiny Guizotia abyssinica (Niger seed), which is a favorite of smaller finches.
Seed feeders are mainly squirrel proof, tube-like or hopper. Due to the need of keeping squirrels away from the bird food, manufacturers have created different defense mechanisms that may deter squirrels from getting close to the seed. Some seed feeders come with weight sensitive technology which shuts off the access to the seed ports whenever a heavy weight is detected (as most squirrels are heavier than birds). Birds can still feed as they weigh less and the ports remain open under their weight. Other seed feeders are designed to be mounted on poles as it is believed that squirrels reach seed feeders more easily from trees than from poles. The simplest type of squirrel proof feeder is a tube-like feeder surrounded by a metal cage. These feeders also offer protection from larger and more aggressive birds. Tube seed feeders are primarily made of clear plastic tubes with plastic or metal caps, bases and perches. Hopper bird feeders look like a house and attract a wide range of birds such as finches, cardinals, blue jays, sparrows and titmice.