Bird species use different building materials to create nests of various shapes and sizes. And the eggs they lay differ in shape, markings, colors, and size. These traits can help you identify the species even if the bird itself isn't present. For instance, rock pigeons build their loose platform nests in nearly any sheltered location, and American robin's eggs are a trademark blue color that many people can recognize.
Here's how to identify some common bird species—including the house finch, northern mockingbird, mallard, black-capped chickadee, and more—by nest type and eggs.
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House Finch Nest
The house finch is one of the most common backyard birds and can be found in nearly any habitat. Its nests show just as much adaptability. The cup-shaped house finch nest is constructed from twigs, grasses, and leaves. And it can be found in many locations, including in trees, shrubs, and cacti; on the ground; under house eaves; and in nesting boxes. House finch eggs are 0.75 to 0.8 inches long with a very pale blue color and small, infrequent spots that are typically concentrated on the larger end of the egg.Continue to 2 of 12 below.
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Vermilion Flycatcher Nest
The eye-catching vermilion flycatcher is a favorite among birders because of its brilliant plumage, and its nests and eggs are just as lovely. The cup-shaped nest is sturdily constructed out of sticks, grass, rootlets, and similar materials. Plus, it is often decorated with bits of moss or lichen that help serve as camouflage. The eggs are approximately 0.75 inches long and are a creamy white with bold, thick blotches of lavender, brown, or gray.Continue to 3 of 12 below.
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American Robin Nest
American robin eggs are among the easiest to recognize with their pale or medium blue color that typically lacks markings. On occasion, robin eggs, which are just over 1 inch long, can also be white or lightly speckled. An American robin’s deep cup nest is constructed from grass and mud and lined with finer grass. Robins build their nests in the crook of a tree, on a nesting shelf, or in nearly any sheltered location.Continue to 4 of 12 below.
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Northern Mockingbird Nest
A northern mockingbird’s nest uses an array of unusual materials, including sticks, stems, and bits of fabric or string. The birds prefer to build deep cup nests between 3 and 10 feet off the ground. The eggs of a northern mockingbird are just 1 inch long with a bluish-green color and dark brown speckles or splotches.Continue to 5 of 12 below.
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Anna's Hummingbird Nest
All hummingbird nests are sturdily built, and the Anna’s hummingbird uses plant down, spider silk, and similar fine materials to construct its cup-shaped nest. These nests are often balanced in precarious locations, such as on thin branches or twigs, on a cliff ledge, or even astride a wire. A nest is then lined with feathers to gently cradle the 0.5 inch long, white, symmetrically oval eggs.Continue to 6 of 12 below.
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Mute Swan Nest
Male and female mute swans work together to build a flattish, mound-shaped nest of assorted plant materials that is sparsely lined with feathers and down. Nests are often built on isolated islands or along shorelines near sources of water while still being concealed from both humans and predators. The eggs are 4.5 inches long and a light gray or blue color, though they can have brown or gray stains from marsh material.Continue to 7 of 12 below.
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Rock Pigeon Nest
Just as rock pigeons are amazingly adaptable to urban habitats, so are their nesting preferences. Pigeons will build a loose platform of sticks, leaves, weeds, and grass in nearly any sheltered location, including gutters, building ledges, windowsills, abandoned boxes, and planters. Pigeons generally lay two white, unmarked eggs that measure 1.5 inches long. Unlike many birds, rock pigeons can breed at any time of year as long as there are sufficient resources for them to raise their young.Continue to 8 of 12 below.
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A killdeer’s nest at first might seem to be no nest at all. Their nests can be simple depressions lined with pebbles or twigs, and some even have no lining. Because killdeers lay their eggs on open ground, their nests are highly vulnerable to predators. Parent birds will often feign injuries to draw predators away from a nearby nest with its light-colored eggs that have black and brown splotches. Eggs are usually 1.5 inches long and somewhat pointed, so they don't roll easily on flat ground.Continue to 9 of 12 below.
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Herring Gull Nest
The herring gull prefers to lay eggs in sheltered ground or roof locations with minimal nest construction, though parent birds will line the nest site with weeds, grass, or seaweed. The eggs can vary from a gray or brown hue to a faint blue or green; they are marked with brown, lavender, or black streaks and spots. The eggs are around 2.6 to 3 inches long. Because they aren't in a deep nest, they are slightly pointed to minimize rolling.Continue to 10 of 12 below.
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Because mallards are the most widespread duck in North America, they have learned to build nests nearly anywhere, including beneath shrubs, tucked into thickets, or even in planters and flowerbeds. Preferred locations are moderately concealed, and each nest is a shallow depression lined with assorted plant material, down, and feathers. The eggs are a buff, cream, or grayish color and measure 2.3 inches long.Continue to 11 of 12 below.
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Black-Capped Chickadee Nest
Black-capped chickadees are prolific nesters and have large broods. They are cavity-nesting birds and will use birdhouses as well as snags and other natural nesting holes, including reusing woodpecker nesting sites. The nests are lined with moss, feathers, and animal fur. The oval, 0.6-inch eggs are marked with brownish speckling.Continue to 12 of 12 below.
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European Nightjar Nest
All species of nightjars, including European nightjars, nest on the ground or any level, open surface, such as a flat rooftop. They use very little nesting material, and often the eggs are simply out in the open or in a very shallow depression dug into dirt or gravel. The oval, 1.25-inch eggs are white with brown and gray splotchy markings.