By nesting at different levels in deciduous woods of the Mid-Atlantic States, a variety of small birds raise young in the same forests with reduced competition for food and nursery sites among them. Each woodland has six layers from the bottom up, the stream level, leaf-covered, bottomland floors, upland floors, shrub layers, young tree layer and the canopy. And each level has a few kinds of birds nesting and foraging for invertebrates in it. Some species use more than one level, allowing them to overlap other species. And most of these birds blend into their niche or niches, helping protect them from predators.
Louisiana waterthrushes, which is a kind of warbler, and Acadian flycatchers nest at the stream level in woods, the former species in crevices in the stream banks themselves, often behind tree roots, and the latter kind in a hanging cup on tree twigs brushing low to waterways. Both species eat invertebrates, the waterthrushes from under stones in shallow water and stream edges, and the flycatchers from the air.
Veeries, which are a type of thrush, and worm-eating warblers rear offspring on dead-leaf, bottomland forest floors near small waterways in the woods. Worm-eaters specialize in nesting on woodland slopes just above the waterways.
On upland forest floors, ovenbirds, which are a species of warbler, and whip-poor-wills, a type of nightjar, hatch youngsters in the leaf litter. Ovenbirds build a leafy dome over their nurseries and create an entrance in the side of each one. Whip-poor-wills, which are so-named because of their loud, repetitive night calls, lay two eggs per clutch on top of the leafy carpet. Ovenbirds consume invertebrates from the woodland floors by day and whip-poor-wills catch flying insects at night.
Female wood thrushes and rose-breasted grosbeaks build nests in the shrub and sapling tree layers. The thrushes get much of their food from the forest floor as their relatives, the robins, do from grassy lawns. The grosbeaks feed mostly in the shrub layer. Male rose-breasts are black on top and white below, with red on their chests, hence their species name. Male wood thrushes sing lovely, flute-like songs while the grosbeaks have robin-like songs that are more melodious than the robins'.
Three species of common birds, scarlet tanagers, red-eyed vireos and eastern wood pewees, which are a kind of flycatcher, feed and nest in or near forest canopies, or treetops, though they are hard to see among the foliage so high and against the bright sky. A key to identifying them in the canopy is to know and hear their distinctive songs.
Tanagers mostly nest 50 feet or more high in the canopies of oak trees in the forests. Females make flimsy cradles of twigs, bark strips, rootlets and grass on forks of twigs. Female tanagers are green, which allows them to blend into their treetop habitats, but their mates are red with black wings and tails. Tanagers eat sluggish insects from canopies, and forest floors at times.
Female red-eyed vireos build cups of bark strips, twigs, wasp nest paper and suspend them below forks of twigs with spider webbing about ten to fifteen feet above the ground. Vireos ingest insects from treetop foliage and that's where the males sing their short, but unending series of phrases most all day every summer day. For this they are called preacher birds.
Female eastern wood pewees create pretty nests on top of small, horizontal limbs of forest trees, nurseries that are hard to see from below. Each cradle is an open cup of bark strips, grasses and lichens attached to the branch by spider webbing about fifteen to sixty feet above the ground. Pewees catch flying insects at all levels in the woods and males sing a beautiful, whistled "pee-a wee, pee-oooo", which is particularly heart-rending at dusk.
Watch and listen for these birds in summer woodlands in the Middle Atlantic States. Many species nest there because each kind uses a different niche in various forest layers with limited interference of other types of birds.
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