Where a bird lives is determined by a series of evolutionary adaptations. This history ties a species to a particular habitat, of which there are ten basic types defined here. Most birds cannot tolerate drastic changes in their environment. Mockingbirds can be found in urban, suburban, and even desert habitats, but ptarmigans can be found on tundra only. The seed-cracking bill of a finch, the thin bill of the insect-eating warbler, and the fish-tearing hooked bill of an eagle all determine the appropriate habitat for these birds.
Open ocean and deep salt water. Pelagic or oceanic species like this spectacular albatross spend their entire lives, except for breeding, at sea. Other birds may spend only certain seasons on the ocean, either far out at sea or on the protected waters of coastal bays.
Marshes grow in both fresh and salt water. They are always rich birding habitats, even though some marsh birds are hard-to-see skulkers. Yellow-headed Blackbirds, bitterns, and rails prefer wet marshes with their cattails, rushes, sedges and grasses.
Many birds, including many ducks and geese, spend their time on the fresh waters of lakes, ponds, rivers, and streams.
Treeless tundra has dense, low ground cover, spongy or dry, including mosses, flowers, and dwarf shrubs. This habitat occurs in the far north and near the tops of mountains. The high Arctic tundra, is home to the Rock Ptarmigan.
Any dry region might be called a desert, but our typical desert birds live in hot, dry lowlands with cactus or scattered low shrubs, as in the Southwest. Roadrunners and Cactus Wrens are found here.
Various forest types, each with different birds, may be mainly deciduous (broad-leaved), coniferous (evergreen), or mixed. Some birds live in the treetops, others in the understory or on the ground. Great Gray Owls inhabit the deep, dark northern forest.
Brushy habitats areas without tall trees but with a dense cover of low growth are common mainly in the West. Types include chaparral, sagebrush, oak scrub, and mesquite brushland. Sage Sparrows like the dry, shrubby habitat of the chaparral.
The edge of the water is a favored habitat for many birds. Shores may be muddy, sandy, or rocky, and may be coastal or along ponds and rivers far inland. The numerous species of sandpipers can be seen on both fresh and saltwater shores.
Many birds favor open areas of grass and wildflowers, from small fields and meadows to the wide horizons of the Great Plains. Some prairie birds also live in pastures and farm fields. Burrowing Owls are indicator birds of flat, prairie grasslands.
Some of our native birds have also adapted well to urban and suburban life and can be seen around city centers, residential neighborhoods, docks, and garbage dumps. The starling, introduced here from Europe, thrives in our cities and suburbs.
A Niche Within a Habitat
In a woodland habitat, many species of birds can exist by selecting different areas in which to feed. Ovenbirds and Rufous-sided Towhees scratch in the undergrowth, Carolina Wrens forage in the bushes, White-breasted Nuthatches hunt for insects on tree trunks, Black-capped Chickadees find food in the middle story of the tree, Scarlet Tanagers like the leafy canopy, and overhead Tree Swallows hawk insects in the sky.