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How many kinds of birds are there?
There are more than 8,000 species of birds.

How many bird species migrate?
In the Western Hemisphere, about 200 species of birds are migratory. The definition of a neotropical migratory bird species is one in which the majority of individuals breeds north of the Tropic of Cancer (which crosses northern Mexico and northern Cuba) and winters south of that same latitude. The majority of neotropical migrants are songbirds, but many shorebirds and some raptors migrate.

Why do birds migrate?
Birds migrate in spring to find distant areas of longer daylight, which produce richer supplies of insects and fruits for enhanced breeding and the raising of young. They migrate in fall to avoid increasing scarcity of food and open water.

How do birds find their way?
Migratory birds use a variety of navigational cues for finding their way between breeding and wintering sites. Birds that travel by day, including hawks and vultures, swallows, swifts and nighthawks use the angle of the setting sun (and the pattern of polarized light created), land features such as mountains and rivers, and wind direction. Birds that travel by night or over vast ocean distances, such as warblers, swallows and thrushes, use a combination of star patterns, the earth's magnetic field, and odors. At least some birds can detect ultraviolet radiations and very deep sound vibrations such as distant ocean waves. When one set of cues is obscured, as the sun and stars may be by cloud cover, more reliance is placed on alternate cues.

For birds that migrate short distances and for most waterfowl, young birds learn migration routes from more experienced family members. Most birds that migrate long distances are genetically predisposed to fly in a certain direction for a certain amount of time. Their first migration is genetically directed. As the birds gain experience after their first trip, they acquire learned information about routes.

Do birds return to the same place on each trip?
Among short distance migrants and most waterfowl species, young birds learn breeding and wintering locations from older, more experienced birds. For long distance migrants that have made their first genetically programmed migration, learning from experience takes over and they incorporate information about successful breeding and wintering sites, frequently returning to the same places.

What's the record for the longest migration on the planet?
The artic tern travels 22,000 annual round trip miles, between nesting grounds on the Arctic tundra and wintering grounds near the South Pole.

How high can they fly?
Migrating birds change their flight altitudes according to a variety of variables, including weather, wind direction and intensity, and whether they are flying over water or land. Most songbirds migrate at 500 to 2,000 feet, but some fly as high as 6,800 feet. Shorebirds migrate at between 1,000 and 13,000 feet, waterfowl between 200 and 4,000 feet, and raptors between 700 and 4,000 feet.

Do birds that breed in the Southern Hemisphere migrate?
Very few go to the Northern Hemisphere, except sea birds.

Why do chickadees, finches, and some robins stay in the north for the winter?
Migrating species are divided into groups of long-distance migrants, short-distance migrants, and partial migrants, which are those species in which some individuals leave their breeding areas in fall and others stay, such as some robins that switch from eating worms and insects to fruit. Many species of birds can tolerate colder temperatures as long as food is plentiful. When insects are no longer available in cold weather, chickadees switch to seeds, which are still plentiful in winter. Finches feed on pine seeds from cones that are available in winter.

How long do birds live?
Life expectancy is roughly correlated with size. Small songbirds may live to about 12 years. Even relatively small seabirds, such as terns, tend to have long lives for their size, actively breeding even after more than 20 years. Longevity in the wild almost never reaches the figures attained by captive birds guarded against disease and predation. Few birds die of "old age"—they continually encounter risks of predators, hunters, bad weather, and obstacles such as buildings and windows. The bright lights of cities create disorientation, and it is estimated that more than a hundred million migrants die each year when they collide with high-rise windows. As many as half of all migrants toward their wintering sites will not return to the northern breeding sites in spring.

Starry Transit: An Installation by Martha Glowacki, presented by the Madison Museum of Contemporary Art, permits visitors to Washburn Observatory to manipulate sculptures that illuminate bird flight, migratory flyways, and seasonal positions of constellations.