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Birdaday Field Notes

Nesting reference

Bird egg identification: the eggs of 18 backyard nesters

Updated

To identify a bird egg, match four things together: its color and markings, its size, how many eggs are in the clutch, and the nest it sits in. Color alone rarely settles it. American Robins, Eastern Bluebirds and European Starlings all lay unmarked bluish eggs, but the robin's sit in a mud-strengthened cup in a tree or on a ledge, the bluebird's in a grass nest inside a cavity or nest box, and the starling's in a cavity stuffed with grass and trash (Cornell Lab of Ornithology, All About Birds). The chart below puts egg, clutch and nest side by side for 18 common US backyard nesters. Look without touching: the eggs and nests of native birds are protected by federal law (U.S. Fish and Wildlife Service).

Jump to: Chart · Eggs to scale · Eggs, nests and the law · If a nest or egg falls

Blue or green, unmarked: American Robin · Eastern Bluebird · European Starling

Bluish, spotted: Blue Jay · Song Sparrow · House Finch · American Goldfinch

White or tinted, speckled: Northern Cardinal · House Sparrow · Brown-headed Cowbird · Black-capped Chickadee · Tufted Titmouse · House Wren · Carolina Wren

Plain white: Mourning Dove · Downy Woodpecker · Tree Swallow · Ruby-throated Hummingbird

Bird egg identification chart: color, size, clutch and nest

Rows are grouped by egg color, in the order of the drawing and species notes below.

# Species Egg color and markings Length Clutch Nest and site
1 American Robin Sky blue or blue-green, unmarked 1.1–1.2 in 3–5 Grass-and-twig cup with mud; tree, gutter, eave, light fixture
2 Eastern Bluebird Pale blue, rarely white 0.7–0.9 in 2–7 Grass or pine needles in a cavity or nest box
3 European Starling Bluish or greenish white 1.1–1.3 in 3–6 Cavity stuffed with grass and trash; buildings, streetlights, boxes
4 Blue Jay Bluish or light brown, brownish spots 1.0–1.3 in 2–7 Twig cup 10–25 ft up in a tree
5 Song Sparrow Blue, blue-green or gray-green, spotted 0.7–0.9 in 1–6 Grass cup hidden in grass or weeds, ground to 15 ft
6 House Finch Pale blue to white, fine black and pale purple speckles 0.6–0.8 in 2–6 Cup in trees or on buildings: vents, ledges, planters
7 American Goldfinch Pale bluish white, sometimes faint spots 0.6–0.7 in 2–7 Woven cup lined with plant down, high in a shrub or small tree
8 Northern Cardinal Grayish, buffy or greenish white, speckled 0.9–1.1 in 2–5 Twig cup in a dense shrub or vines, 1–15 ft up
9 House Sparrow White to greenish or bluish white, spotted 0.8–0.9 in 1–8 Cavity packed with coarse dry plants
10 Brown-headed Cowbird White to grayish white, spotted 0.7–1.0 in 1–7 None: laid in other birds' nests
11 Black-capped Chickadee White, fine reddish-brown dots 0.6 in 1–13 Moss and fur in a cavity or box
12 Tufted Titmouse White to cream, reddish to lilac spots 0.7–0.8 in 3–9 Leaves and moss lined with hair, in a cavity or box
13 House Wren White, pinkish or grayish, reddish-brown specks 0.6–0.8 in 3–10 Cavity or box filled with twigs
14 Carolina Wren White, cream or pinkish, rusty spots 0.7–0.8 in 3–7 Domed nest with a side entrance
15 Mourning Dove White, unmarked 1.0–1.2 in 2 Flimsy twig platform in foliage, gutters, eaves
16 Downy Woodpecker Completely white 0.8 in 3–8 Cavity in dead wood, wood chips only
17 Tree Swallow Pale pink, pure white within 4 days 0.7–0.8 in 4–7 Grass cup lined with feathers, cavity or box
18 Ruby-throated Hummingbird Tiny, white 0.5–0.6 in 1–3 Thimble-sized cup on top of a branch

All columns: the Nesting Facts and nest notes on each species' All About Birds life-history page (Cornell Lab). Use several columns together; one feature alone often fits more than one row.

Eggs drawn to scale

Eggs of 18 backyard birds drawn to one scaleEgg shapes numbered 1 to 18 in chart order, drawn to one scale with a 1-inch bar: bluish eggs in the top row, speckled whitish eggs in the middle, plain white eggs at the end of the bottom row. The starling, robin, Blue Jay and Mourning Dove eggs are largest; the hummingbird egg is smallest. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 1 inch
  1. American Robin
  2. Eastern Bluebird
  3. European Starling
  4. Blue Jay
  5. Song Sparrow
  6. House Finch
  7. American Goldfinch
  8. Northern Cardinal
  9. House Sparrow
  10. Brown-headed Cowbird
  11. Black-capped Chickadee
  12. Tufted Titmouse
  13. House Wren
  14. Carolina Wren
  15. Mourning Dove
  16. Downy Woodpecker
  17. Tree Swallow
  18. Ruby-throated Hummingbird
Drawn for Birdaday Field Notes from the egg lengths, widths and descriptions on each species' All About Birds life-history page, cited below, at the middle of each range. Shapes are generic, colors approximate and spot patterns illustrative.

Blue or green eggs, unmarked

American Robin

The cup of grass and twigs is reinforced with mud and lined with fine grass, 6–8 inches across; of the three unmarked blue eggs here, only the robin's sit in mud (Cornell). See the American Robin profile.

Eastern Bluebird

Smaller than a robin's, in a cavity or box. Sialis.org: no dark spots, and the nest is typically all fine grass or pine needles. See the Eastern Bluebird profile.

European Starling

Larger than a bluebird's, in an enclosed space packed with grass, pine needles and debris; fresh green plants are added during laying (Cornell). An introduced species; compare starling vs grackle.

Bluish eggs with spots

Blue Jay

Among the largest eggs here, in an open cup of twigs and grass lined with root fibers, high in a tree (Cornell). See the Blue Jay profile.

Song Sparrow

Spotted brown, red-brown or lilac. Nests are usually hidden low in grass or weeds, often near water, and sometimes in flower beds near houses (Cornell).

House Finch

Nests on buildings as readily as in trees, and sometimes in other birds' old nests (Cornell). See the House Finch profile.

American Goldfinch

Any faint brown spots sit around the large end. The woven cup is tight enough to hold water (Cornell). See the American Goldfinch profile.

White or tinted eggs with speckles

Northern Cardinal

Among the larger speckled eggs here, in a layered twig cup in dense cover; cardinals rarely reuse a nest (Cornell). See the Northern Cardinal profile.

House Sparrow

Lined with feathers, cord or paper (Cornell); Sialis.org calls a box nest "a loose jumble of odds and ends." Introduced; see keeping House Sparrows out of birdhouses.

Brown-headed Cowbird

Cowbirds build no nest; females lay in other birds' nests, and more than 140 host species are known (Cornell). Audubon shows a white cowbird egg among a robin's blue eggs.

Black-capped Chickadee

Tiny eggs in a downy moss-and-fur nest; Sialis.org notes the female may pull a plug of moss or fur over them when she leaves. See the Black-capped Chickadee profile.

Tufted Titmouse

Sialis.org: speckling more evenly spread than a chickadee's. The lining is hair, sometimes plucked from live mammals (Cornell). See the Tufted Titmouse profile.

House Wren

Sialis.org says the specks often form a ring at the large end. A small, soft cup sits in a hollow among the twigs (Cornell).

Carolina Wren

The nest gives it away: a roomy domed cup with a side entrance, often in sheltered spots or household objects (Cornell). See the Carolina Wren profile.

Plain white eggs

Mourning Dove

Two large white eggs on an unlined platform about 8 inches across (Cornell). See the Mourning Dove profile.

Downy Woodpecker

Laid on wood shavings in a cavity both adults dig, with a round entrance a bit over an inch wide (Cornell). See the Downy Woodpecker profile.

Tree Swallow

Sialis.org: Tree Swallow nests are usually lined with feathers, bluebird nests typically not, which helps with a rare white bluebird clutch.

Ruby-throated Hummingbird

About half a gram each. The nest of plant down and spider silk, camouflaged with lichen, sits on top of a slender branch (Cornell). See the Ruby-throated Hummingbird profile.

Eggs, nests and the law

A summary of U.S. Fish and Wildlife Service (USFWS), Audubon and Cornell Lab guidance, not legal advice; for a specific case, ask USFWS or your state wildlife agency.

If a nest or an egg falls

  1. Check it is really abandoned. Parents are secretive at the nest and almost always return after a scare; watch from a distance (Cornell).
  2. One unbroken egg on the ground: if you know its nest and can reach it safely, gently put it back (Sialis.org), but only if the other eggs match (Toronto Wildlife Centre). Never put it in a different nest (Sialis.org).
  3. A whole nest down: secure a rebuilt nest as close as possible to where it fell (Toronto Wildlife Centre). Audubon, citing Cornell, describes a berry basket lined with soft material, with drainage holes, tied securely to the tree.
  4. Nestlings: put them back; parents do not recognize young by smell (Cornell). If two hours pass with no adult, Audubon says to contact a wildlife rehabilitation center or veterinarian. More in found a baby bird.
  5. Don't incubate eggs yourself (Cornell, Toronto Wildlife Centre). Sialis.org says only licensed rehabilitators may raise wild birds, and they do not incubate eggs unless the species is endangered.
  6. Nest in a dangerous spot such as a tailpipe: don't move it; Audubon says to call a wildlife rehabilitator.

Sources