**Bird Egg Identification Chart — Match by Colour, Size & Nest**

> Free bird egg identification key. Filter 34 North American birds by egg colour, markings, size and where the nest was, and find out what to do with an egg you have found.

Source: https://orvik.app/tools/bird-egg-identifier/ · updated: 2026-09-03

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# Whose egg is this?

Egg colour on its own is ambiguous — a dozen species lay pale blue. What is **not** ambiguous is colour plus size plus nest. Measure the long axis against a coin, note whether the nest was a cup in a shrub, a hole in a tree or a scrape on the ground, and the list collapses to two or three.

Entries **34** Filters **4** Updated **2026-09-03** Cost **Free, no account**

**In the United States it is illegal to collect, keep or disturb the eggs of almost any wild bird.** The Migratory Bird Treaty Act covers over 1,000 species and applies to eggs, nests and feathers, with no exception for eggs you found on the ground. Photograph it, leave it where it is, and do not move an active nest. The UK Wildlife and Countryside Act and the EU Birds Directive say the same thing.

Narrow it down

Clear all

Search birds by name

Ground colour

White or cream Blue or blue-green Buff, tan or pink Olive or brown Grey

Markings

No markings at all Fine speckles Bold blotches or splotches A ring of marks around the fat end Squiggles or hair-like lines

Length of the egg

Long axis. A US quarter is 24 mm across; a UK 10p is 24.5 mm.

Under 18 mm 18–24 mm 24–35 mm 35–50 mm Over 50 mm

Where the nest was

Cup in a shrub or tree Hole in a tree or a nest box On the ground or a scrape On a building, ledge or eave At water's edge or floating In a burrow or bank Loose, no nest found

Showing all 34 birds

1. ### American robin Turdus migratorius Unmarked, saturated sky-blue — the colour that has its own paint-chart name — in a mud-lined cup on a horizontal branch, a porch light or a ledge. Three or four to a clutch. Size 28–30 mm Where The whole of North America. Confused with Eastern bluebird and starling eggs are also blue, but bluebird eggs are paler and smaller and starling eggs are more elongated with a faint gloss. In the record 29,399,206 georeferenced records · half of them Mar–Jun · most distinctive in June · mostly from the United States [check on GBIF](https://www.gbif.org/species/9510564)

2. [What bird is this?](https://orvik.app/birds/what-bird-is-this/)

3. ### Eastern bluebird Sialia sialis Pale powder-blue and unmarked, in a neat grass cup inside a nest box or a woodpecker hole. About one clutch in twenty is pure white, which throws people every year. Size 20–22 mm Where Eastern and central North America. In the record 8,081,487 georeferenced records · half of them Jan–May · most distinctive in February · mostly from the United States [check on GBIF](https://www.gbif.org/species/2490941)

4. ### European starling Sturnus vulgaris Glossy pale blue and unmarked, more elongated than a robin's, in an untidy mass of grass and rubbish stuffed into a building cavity, vent or nest box. Size 27–32 mm Where Introduced across North America; native to Eurasia. In the record 28,298,900 georeferenced records · half of them Jan–May · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/9809229)

5. ### House sparrow Passer domesticus Off-white to grey-green with dense grey-brown speckling that varies wildly within one clutch, in a bulky untidy nest of grass and litter crammed into a hole in a building or a box. Size 20–23 mm Where Towns and farms worldwide. In the record 25,809,906 georeferenced records · half of them Jan–May · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/5231190)

6. ### House finch Haemorhous mexicanus Very pale blue-white with a sparse scatter of fine black dots and thin squiggles concentrated at the fat end, in a small cup in a hanging basket, a wreath on a door, or a conifer. Size 16–21 mm Where Across North America. In the record 19,217,637 georeferenced records · half of them Jan–May · most distinctive in February · mostly from the United States [check on GBIF](https://www.gbif.org/species/8323485)

7. ### Northern cardinal Cardinalis cardinalis Greyish-white heavily marked with brown and grey blotches, in a loose cup of twigs and bark strips deep inside a dense shrub or a tangle of vines, usually one to three metres up. Size 24–27 mm Where Eastern and central North America. In the record 27,192,474 georeferenced records · half of them Jan–May · most distinctive in February · mostly from the United States [check on GBIF](https://www.gbif.org/species/2490384)

8. ### Blue jay Cyanocitta cristata Buff to pale olive with fine brown speckling, in a bulky twig cup high in a conifer or oak. Larger and duller than a robin egg despite the bird's colour. Size 25–30 mm Where Eastern and central North America. In the record 24,084,106 georeferenced records · half of them Jan–Jun · most distinctive in October · mostly from the United States [check on GBIF](https://www.gbif.org/species/2482593)

9. ### American crow Corvus brachyrhynchos Blue-green heavily blotched with brown and grey, in a big stick nest high in a tree. Size alone separates it from every songbird on this list. Size 40–45 mm Where Across North America. In the record 29,072,171 georeferenced records · half of them Jan–May · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2482507)

10. ### Mourning dove Zenaida macroura Pure unmarked white, always exactly two, on a flimsy platform of a few dozen twigs so thin you can often see the eggs through it from below. Size 26–30 mm Where Across North America. Confused with Rock pigeon, which lays the same two white eggs but on a building ledge and slightly larger. In the record 27,323,324 georeferenced records · half of them Jan–May · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/2495347)

11. ### Rock pigeon Columba livia Two plain white eggs on a rough platform on a ledge, bridge girder or building recess. Larger than a dove's and almost always in built structure rather than vegetation. Size 36–40 mm Where Cities worldwide. In the record 15,562,872 georeferenced records · half of them Jan–Jun · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/2495414)

12. ### Barn swallow Hirundo rustica White with fine reddish-brown speckling, in a cup of mud pellets and straw stuck to a beam, joist or wall inside a barn, porch or culvert. Size 18–20 mm Where Across North America, Europe and Asia. In the record 17,480,186 georeferenced records · half of them Mar–Jun · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/9515886)

13. ### American goldfinch Spinus tristis Tiny, very pale blue-white and unmarked, in an exceptionally tight thistledown-lined cup that holds water. Nests in late July and August, far later than anything else in the garden. Size 16–18 mm Where Across North America. In the record 20,295,243 georeferenced records · half of them Mar–Jul · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/5231640)

14. ### Black-capped chickadee Poecile atricapillus Tiny white eggs with fine reddish dots concentrated in a ring at the fat end, on a bed of moss and animal fur inside a small tree cavity or nest box. Size 15–16 mm Where Northern North America. In the record 18,773,574 georeferenced records · half of them Jan–May · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2487805)

15. ### Carolina wren Thryothorus ludovicianus Creamy white with dense rusty speckling wreathed at the broad end, in a domed nest with a side entrance built in a hanging basket, a boot, a mailbox or a shelf in a shed. Size 18–20 mm Where The eastern United States. In the record 12,910,434 georeferenced records · half of them Jan–Jun · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2493801)

16. ### House wren Troglodytes aedon Tiny, so densely covered in fine reddish speckles that the eggs look uniformly pinkish-brown, on a platform of twigs jammed into any cavity — a box, a pipe, a coat pocket in a shed. Size 16–17 mm Where Across North America. In the record 6,609,621 georeferenced records · half of them Apr–Jun · most distinctive in June · mostly from the United States [check on GBIF](https://www.gbif.org/species/5231459)

17. ### Mallard Anas platyrhynchos Large, unmarked, greenish-buff to cream with a smooth waxy surface, eight to thirteen in a down-lined hollow on the ground, often surprisingly far from water — including in planters and courtyards. Size 55–62 mm Where Across the northern hemisphere. In the record 29,635,278 georeferenced records · half of them Jan–May · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/9761484)

18. ### Canada goose Handle with care Branta canadensis Very large plain creamy-white eggs, four to seven, in a big down-lined bowl on a bank, island or flat roof. The parents defend it aggressively. Size 80–90 mm Where Across North America and introduced in Europe. Risk A nesting goose will attack. Keep well back and route around it rather than trying to pass. In the record 23,296,736 georeferenced records · half of them Feb–May · most distinctive in March · mostly from the United States [check on GBIF](https://www.gbif.org/species/5232437)

19. ### Killdeer Charadrius vociferus Four pointed buff eggs heavily blotched black, arranged points-inward in a bare scrape on gravel — a driveway, a car park, a flat roof. They are almost invisible until you are on top of them. Size 35–38 mm Where Across North America. Confused with A scatter of gravel. That is the point. If a bird nearby is dragging a wing and screaming, you are standing near the nest. In the record 9,888,720 georeferenced records · half of them Mar–Jun · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/2480320)

20. ### Wild turkey Meleagris gallopavo Ten to fourteen large pale buff eggs finely speckled reddish-brown, in a shallow leaf-lined depression at the base of a tree or under a brush pile. Size 60–65 mm Where Woodland and field edge across North America. In the record 2,840,016 georeferenced records · half of them Feb–May · most distinctive in April · mostly from the United States [check on GBIF](https://www.gbif.org/species/9606290)

21. ### Ring-necked pheasant Phasianus colchicus Eight to fifteen plain glossy olive-brown eggs with no markings at all, in a grass-lined scrape in tall cover at a field edge. Size 42–46 mm Where Introduced across North America and Europe. In the record 3,428,744 georeferenced records · half of them Feb–May · most distinctive in April · mostly from the United States [check on GBIF](https://www.gbif.org/species/9752149)

22. ### Northern bobwhite Colinus virginianus A dozen or more small, pure white, distinctly pointed eggs packed tightly into a domed grass nest woven closed over the top. Size 29–31 mm Where The eastern and central United States. In the record 500,837 georeferenced records · half of them Apr–Jun · most distinctive in June · mostly from the United States [check on GBIF](https://www.gbif.org/species/9791464)

23. ### Red-winged blackbird Agelaius phoeniceus Pale blue-green covered in dark brown and purple scrawls and hair-lines that look like handwriting, in a woven cup lashed to cattail stems just above the water. Size 24–26 mm Where Marshes and wet fields across North America. In the record 21,105,852 georeferenced records · half of them Mar–May · most distinctive in May · mostly from the United States [check on GBIF](https://www.gbif.org/species/9409198)

24. ### Common grackle Quiscalus quiscula Pale blue to light brown with heavy dark brown scrawls and blotches, in a bulky mud-reinforced cup in a conifer, often in a loose colony of several pairs. Size 28–32 mm Where Eastern and central North America. In the record 12,356,348 georeferenced records · half of them Mar–May · most distinctive in May · mostly from the United States [check on GBIF](https://www.gbif.org/species/2484155)

25. ### Brown-headed cowbird Molothrus ater Greyish-white with dense brown speckling, and — the identifying feature — it is the odd one out in somebody else's nest: larger, differently coloured, and often already hatched first. Size 21 mm Where Across North America. Confused with Nothing, once you know the trick. A single mismatched egg in a warbler, sparrow or vireo nest is almost always a cowbird. Risk Cowbird eggs are also protected under the Migratory Bird Treaty Act. Removing one is illegal without a permit. In the record 8,428,231 georeferenced records · half of them Apr–May · most distinctive in May · mostly from the United States [check on GBIF](https://www.gbif.org/species/2484391)

26. ### Song sparrow Melospiza melodia Pale greenish-blue so heavily blotched with red-brown that the ground colour barely shows, in a grass cup on or near the ground in dense cover. Size 20–23 mm Where Across North America. In the record 22,455,511 georeferenced records · half of them Mar–Jun · most distinctive in June · mostly from the United States [check on GBIF](https://www.gbif.org/species/2492196)

27. ### Mockingbird Mimus polyglottos Blue-green splashed with large rusty-brown blotches, in a twig cup low in a dense shrub. The adults dive-bomb anything that comes near. Size 24–26 mm Where The southern and eastern United States. In the record 11,835,073 georeferenced records · half of them Jan–May · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/5231677)

28. ### Northern flicker Colaptes auratus Glossy pure white and almost translucent, laid on bare wood chips at the bottom of an excavated tree cavity. Woodpeckers do not build nests and do not need camouflaged eggs. Size 26–29 mm Where Across North America. Confused with Every other woodpecker, all of which lay plain white eggs in cavities. Cavity size and location separate them, not the egg. In the record 15,019,736 georeferenced records · half of them Jan–Jun · most distinctive in October · mostly from the United States [check on GBIF](https://www.gbif.org/species/2478259)

29. ### Eastern screech owl Megascops asio Almost perfectly spherical, pure white and slightly rough, in a tree cavity or a nest box with no nest material at all. Roundness is the giveaway — most eggs are noticeably pointed at one end. Size 34–37 mm Where Eastern North America. In the record 495,661 georeferenced records · half of them Jan–May · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2497415)

30. [Owl call identification](https://orvik.app/birds/owl-calls-identification/)

31. ### Great horned owl Bubo virginianus Large, dull white and nearly spherical, laid as early as January in a stolen hawk or crow nest. It does not build its own. Size 53–58 mm Where Across the Americas. In the record 1,643,488 georeferenced records · half of them Jan–May · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/5959118)

32. ### Red-tailed hawk Buteo jamaicensis Large, dull white with sparse pale brown blotches, two or three in a big stick nest high in a tree or on a cliff ledge or building. Size 57–62 mm Where Across North America. In the record 12,455,878 georeferenced records · half of them Jan–May · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/2480542)

33. ### Chimney swift Chaetura pelagica Plain white, in a half-saucer of twigs glued to a vertical chimney wall with the bird's own saliva. Nothing else nests that way in North America. Size 20 mm Where Eastern North America. In the record 3,892,467 georeferenced records · half of them Apr–Jun · most distinctive in May · mostly from the United States [check on GBIF](https://www.gbif.org/species/4409023)

34. ### Herring gull Handle with care Larus argentatus Three large olive-brown eggs with heavy dark blotches, in a scrape on a flat roof, a shingle beach or an island. Adults defend the nest by striking at heads. Size 68–75 mm Where Coasts and cities of North America and Europe. Risk Nesting gulls dive at people and can draw blood. Leave the roof and come back in six weeks. In the record 7,305,082 georeferenced records · half of them Jan–Jun · most distinctive in August · mostly from Belgium [check on GBIF](https://www.gbif.org/species/2481139)

35. ### Ruby-throated hummingbird Archilochus colubris The size of a small pea, plain white, two of them, in a walnut-sized cup of plant down bound with spider silk and camouflaged with lichen on a thin downward-sloping branch. Size 12–14 mm Where Eastern North America. In the record 4,600,516 georeferenced records · half of them Jul–Sep · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/5228514)

36. ### Killdeer, tern and plover scrapes generally Handle with care Charadriiformes Heavily blotched sand-coloured eggs in a bare scrape with no nest material, laid directly on gravel or shell. If you have found eggs on open ground with no nest, this is the group. Size 30–50 mm Where Beaches, gravel bars, roofs and construction sites across North America. Risk Beach-nesting plovers and terns include federally listed species. Leave the area immediately and report it to a local wildlife office rather than investigating. In the record 201,502,803 georeferenced records · half of them Apr–Aug · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/7192402)

Nothing in this key matches every filter at once. That usually means one observation is
off — a colour read in shade, or a size guessed rather than measured. Clear the filter you
are least sure about and look again.

## Why so many eggs are blue

Two pigments produce every egg colour there is. **Biliverdin**, a bile pigment, makes blue and green; **protoporphyrin** makes red, brown and black. They are laid down in the last hours before laying, protoporphyrin last, which is why the speckles sit on the surface and the blue sits in the shell.

That single fact explains several things people find confusing. Speckles concentrate in a ring at the fat end because the egg pauses there in the oviduct while the pigment glands are still working. Markings smudge into comet tails when the egg was still turning as the pigment went on. And the same species can lay noticeably differently marked eggs in successive clutches, because pigment supply varies with the female's condition.

Colour also does real work. Ground-nesting birds — killdeer, pheasant, turkey, gulls, plovers — lay heavily blotched sand-coloured eggs that vanish against gravel. Cavity nesters — woodpeckers, owls, chickadees, bluebirds — lay white or near-white eggs, because nothing can see them anyway and a pale egg is easier for the parent to find in the dark. So **a plain white egg is itself a clue: it usually means a hole**.

## Measure it, and use the nest

Size is the most discriminating character available and the one most often guessed. A robin egg and a house finch egg are both blue, and one is nearly twice the length of the other. Put a coin beside it before you photograph it — a US quarter is 24.3 mm across, a US penny 19 mm, a UK 10p 24.5 mm, a euro 2 coin 25.75 mm.

Nest type then does most of the remaining work:

*What the nest tells you before you have looked at the egg.*

| Nest | Typical egg | Groups |
| --- | --- | --- |
| Hole in a tree, or a nest box | White or pale, often unmarked | Woodpeckers, owls, chickadees, bluebirds, wrens, starlings |
| Open cup in a shrub or tree | Blue, or pale with speckles and blotches | Robins, cardinals, finches, sparrows, mockingbirds, jays |
| Bare scrape on the ground | Buff, heavily blotched, well camouflaged | Killdeer, plovers, terns, gulls, nightjars |
| Grass-lined hollow in cover | Plain olive or buff, large clutch | Ducks, geese, pheasant, turkey, quail |
| Mud cup on a beam or wall | White with fine speckles | Barn and cliff swallows, phoebes |
| Big stick platform high up | Large, dull white or blotched | Hawks, owls, herons, crows, ravens |
| No nest, on somebody else's eggs | Mismatched, speckled | Brown-headed cowbird |

Clutch size is worth counting too, and it is decisive at the extremes. Exactly two plain white eggs on a flimsy twig platform is a mourning dove and essentially nothing else. Twelve to fifteen plain olive eggs in a grass scrape is a game bird. Two pea-sized white eggs in a lichen-covered cup on a drooping branch is a hummingbird.

## The law, which is stricter than most people realise

In the United States the **Migratory Bird Treaty Act** makes it illegal to take, possess, sell or transport the birds, eggs, nests or feathers of over a thousand species without a federal permit. There is no exception for an egg found on the ground, an abandoned nest, or a shell picked up after hatching. Penalties are real, and they apply to well-intentioned collectors as readily as to anyone else.

The species not covered are the introduced ones: house sparrow, European starling, rock pigeon and non-migratory game birds regulated under state law. Everything else — including cowbirds, crows, gulls and every songbird in a garden — is protected.

In the United Kingdom, the Wildlife and Countryside Act 1981 makes it an offence to take or destroy the egg of any wild bird, and possession of any wild bird egg is an offence regardless of when it was collected. The EU Birds Directive is equivalent across member states.

The practical rule everywhere: **photograph it and leave it exactly where it is**. That is not just legal caution — it is also the answer that gives the egg the best chance, which the next section covers.

## You found an egg on the ground. What now?

The honest answer is uncomfortable: an egg out of its nest is almost certainly not going to hatch, and there is very little a person can do about it.

**If the nest is right there and reachable**, and the egg is intact and still warm, put it back. The old belief that a parent bird will abandon a nest because a human touched it is false — most birds have a poor sense of smell and do not detect handling. Getting it back under the parent quickly is worth doing.

**If the nest is unreachable or gone**, leave the egg. Home incubation of a wild bird egg is illegal without a permit, requires temperature control within a fraction of a degree and specific humidity, and even under a licensed rehabilitator has a poor success rate. A hatchling that does survive imprints on people and cannot be released.

**If a whole nest has come down** — after a storm or a hedge cut — the useful action is to fix the nest back as close as possible to where it was, in a container with drainage, and then leave the area completely for a few hours. Parents frequently resume. Standing nearby watching guarantees they will not.

**If eggs are cold and the nest is clearly abandoned**, leave them. Predators and scavengers deal with them within days, and an unattended nest is often a nest whose parents were themselves taken.

The one case where you should act is a nest in immediate danger — on a construction site, in a piece of equipment about to be used, on a driveway. Contact a state wildlife agency or a licensed rehabilitator, who can act legally and quickly. In the US, work near an active nest of a protected species may need to stop until the young fledge, which is a legal obligation on the contractor rather than a request.

## Empty shells and what they tell you

Most eggshells found on the ground are not lost eggs at all, and the way they are broken says which.

**A shell in two clean pieces, with the larger piece a neat cap**, hatched successfully. The chick cuts a ring around the fat end from inside, and the parent then carries the shell some distance from the nest and drops it, which is why hatched shells so often turn up under a tree with no nest in it. A membrane still lining the inside and no yolk residue confirms it.

**A shell crushed, with yolk dried on it,** was predated. Jays, crows, grackles, squirrels, raccoons and snakes all take eggs. A shell with a neat hole punched in the side, found in a nest, often means a squirrel or a jay.

**A whole egg lying on the ground with no nest above** is usually a dumped egg — a female forced to lay before a nest was ready, or an egg pushed out of a nest by a competitor or by a cowbird. Starlings and house sparrows evict the eggs of cavity-nesting natives routinely, which is why bluebird boxes so often have a robin-blue egg on the grass below them.

**A very small, misshapen, yolkless egg** is a runt or fairy egg, produced when a scrap of tissue triggers the shell gland without a yolk present. It is a curiosity rather than a species.

## What this key covers

34 entries covering the birds whose eggs people actually encounter around houses, gardens, farms and beaches in North America, plus the widespread species shared with Europe. North America has over 700 breeding species and a complete egg key would be a book — the standard one, Baicich and Harrison, runs to several hundred pages and still says "not separable" for a great many pairs.

Two limits are worth naming. Within families, eggs are frequently indistinguishable: all woodpeckers lay plain white eggs in cavities, most warblers lay small speckled cream eggs in cups, and the sparrows overlap so heavily that even a specialist works from the nest and the habitat rather than the egg. And variation within a species is wide — ground colour, marking density and size all shift between clutches and between regions.

So treat a match here as a shortlist. The reliable confirmation is the adult bird: sit thirty metres away for ten minutes and watch what comes back to the nest. That single observation outperforms any egg key ever written.

## What the observation record shows

Every entry in this key that carries a scientific name is matched against

- [GBIF](https://www.gbif.org/), the
international register of biodiversity records, and against

- [iNaturalist](https://www.inaturalist.org/).
That puts a hard number behind 34 of the 34birds here:
**501,295,315 georeferenced records** across the 33 entries that resolve to a single species, spanning 23 families, the oldest of them collected in
2013. The snapshot was taken on 2026-09-04.

That evidence is not spread evenly, and it is worth knowing before you trust a narrow
result. The five best-recorded birds in this key hold 29%
of all the records between them: Mallard alone accounts for
29,635,278, while Eastern screech owl has
495,661. A common thing is common in the data too, so
when a filter narrows to one frequent entry and one rare one, the frequent one is
usually the answer — and the record count is the quickest way to see which is which.
The same skew applies geographically: 76% of these
records come from the United States, so the key describes what is
reported there far better than it describes anywhere else.

### When these are actually reported

*Half of the 499,573,922 georeferenced records for these 33 birds fall in January–May alone. The bars are the raw share by month, which mostly measures when people go looking; the line divides each month by the baseline for every species in every Orvik key, so a value above 1.0 means these birds are reported more than the season alone explains, and it peaks in February. Source: GBIF, snapshot 2026-09-04.*

Half of every record for this group falls in January–May.
A raw month count measures two things at once — when the organism is about, and when
people are outdoors with a camera — and the second effect is large enough to give
almost anything a summer peak. The line on the figure divides each month by the
baseline for every species in every Orvik key, which answers a different question:
relative to when people record anything at all, when are these birds recorded?
Values above 1.0 are the months that belong to this group rather than to the season.
On that measure 17 of the 33birds here peak
outside the warm half of the year — Mallard, American crow, European starling among them. Those are the ones a seasonal rule of
thumb gets wrong.

### Records behind each entry

Sorted by how much evidence exists, not by how likely you are to meet one. The peak
month is the effort-adjusted figure, and it is left blank wherever the sample is too
thin for the month-to-month wobble to mean anything.

*GBIF and iNaturalist record counts for the 34 named birds in this key,
 snapshot 2026-09-04. Rows above species rank aggregate everything beneath them and
 are not comparable with the rest. Free to reuse with a link to this page.*

| Entry | Accepted name | Rank | GBIF records | Research-grade | Half fall in | Peak, adjusted | Most reported from |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Mallard | [Anas platyrhynchos Linnaeus, 1758](https://www.gbif.org/species/9761484) | species | 29,635,278 | 953,637 | Jan–May | January | the United States |
| American robin | [Turdus migratorius Linnaeus, 1766](https://www.gbif.org/species/9510564) | species | 29,399,206 | 468,360 | Mar–Jun | June | the United States |
| American crow | [Corvus brachyrhynchos C.L.Brehm, 1822](https://www.gbif.org/species/2482507) | species | 29,072,171 | 219,015 | Jan–May | December | the United States |
| European starling | [Sturnus vulgaris Linnaeus, 1758](https://www.gbif.org/species/9809229) | species | 28,298,900 | 342,952 | Jan–May | January | the United States |
| Mourning dove | [Zenaida macroura](https://www.gbif.org/species/2495347) | species | 27,323,324 | 307,418 | Jan–May | August | the United States |
| Northern cardinal | [Cardinalis cardinalis](https://www.gbif.org/species/2490384) | species | 27,192,474 | 399,788 | Jan–May | February | the United States |
| House sparrow | [Passer domesticus](https://www.gbif.org/species/5231190) | species | 25,809,906 | 561,043 | Jan–May | January | the United States |
| Blue jay | [Cyanocitta cristata](https://www.gbif.org/species/2482593) | species | 24,084,106 | 203,884 | Jan–Jun | October | the United States |
| Canada goose | [Branta canadensis](https://www.gbif.org/species/5232437) | species | 23,296,736 | 482,254 | Feb–May | March | the United States |
| Song sparrow | [Melospiza melodia](https://www.gbif.org/species/2492196) | species | 22,455,511 | 271,066 | Mar–Jun | June | the United States |
| Red-winged blackbird | [Agelaius phoeniceus](https://www.gbif.org/species/9409198) | species | 21,105,852 | 314,510 | Mar–May | May | the United States |
| American goldfinch | [Spinus tristis](https://www.gbif.org/species/5231640) | species | 20,295,243 | 197,293 | Mar–Jul | August | the United States |
| House finch | [Haemorhous mexicanus](https://www.gbif.org/species/8323485) | species | 19,217,637 | 341,628 | Jan–May | February | the United States |
| Black-capped chickadee | [Poecile atricapillus](https://www.gbif.org/species/2487805) | species | 18,773,574 | 166,644 | Jan–May | December | the United States |
| Barn swallow | [Hirundo rustica Linnaeus, 1758](https://www.gbif.org/species/9515886) | species | 17,480,186 | 240,890 | Mar–Jun | August | the United States |
| Rock pigeon | [Columba livia J.F.Gmelin, 1789](https://www.gbif.org/species/2495414) | species | 15,562,872 | 453,483 | Jan–Jun | January | the United States |
| Northern flicker | [Colaptes auratus](https://www.gbif.org/species/2478259) | species | 15,019,736 | 166,439 | Jan–Jun | October | the United States |
| Carolina wren | [Thryothorus ludovicianus](https://www.gbif.org/species/2493801) | species | 12,910,434 | 107,505 | Jan–Jun | December | the United States |
| Red-tailed hawk | [Buteo jamaicensis](https://www.gbif.org/species/2480542) | species | 12,455,878 | 356,631 | Jan–May | January | the United States |
| Common grackle | [Quiscalus quiscula](https://www.gbif.org/species/2484155) | species | 12,356,348 | 119,448 | Mar–May | May | the United States |
| Mockingbird | [Mimus polyglottos](https://www.gbif.org/species/5231677) | species | 11,835,073 | 241,277 | Jan–May | December | the United States |
| Killdeer | [Charadrius vociferus Linnaeus, 1758](https://www.gbif.org/species/2480320) | species | 9,888,720 | 153,428 | Mar–Jun | August | the United States |
| Brown-headed cowbird | [Molothrus ater](https://www.gbif.org/species/2484391) | species | 8,428,231 | 108,482 | Apr–May | May | the United States |
| Eastern bluebird | [Sialia sialis](https://www.gbif.org/species/2490941) | species | 8,081,487 | 155,333 | Jan–May | February | the United States |
| Herring gull | [Larus argentatus Pontoppidan, 1763](https://www.gbif.org/species/2481139) | species | 7,305,082 | 98,058 | Jan–Jun | August | Belgium |
| House wren | [Troglodytes aedon Vieillot, 1809](https://www.gbif.org/species/5231459) | species | 6,609,621 | 57,033 | Apr–Jun | June | the United States |
| Ruby-throated hummingbird | [Archilochus colubris](https://www.gbif.org/species/5228514) | species | 4,600,516 | 98,009 | Jul–Sep | August | the United States |
| Chimney swift | [Chaetura pelagica](https://www.gbif.org/species/4409023) | species | 3,892,467 | 14,764 | Apr–Jun | May | the United States |
| Ring-necked pheasant | [Phasianus colchicus Linnaeus, 1758](https://www.gbif.org/species/9752149) | species | 3,428,744 | 74,184 | Feb–May | April | the United States |
| Wild turkey | [Meleagris gallopavo Linnaeus, 1758](https://www.gbif.org/species/9606290) | species | 2,840,016 | 198,270 | Feb–May | April | the United States |
| Great horned owl | [Bubo virginianus](https://www.gbif.org/species/5959118) | species | 1,643,488 | 92,386 | Jan–May | December | the United States |
| Northern bobwhite | [Colinus virginianus](https://www.gbif.org/species/9791464) | species | 500,837 | 11,287 | Apr–Jun | June | the United States |
| Eastern screech owl | [Megascops asio](https://www.gbif.org/species/2497415) | species | 495,661 | 26,189 | Jan–May | December | the United States |
| Killdeer, tern and plover scrapes generally | [Charadriiformes](https://www.gbif.org/species/7192402) | order | 201,502,803 | 4,752,227 | Apr–Aug | August | the United States |

This table is assembled from open data and is free to reuse with a link back to this
page. The snapshot behind every Orvik key is published as one downloadable file on the

- [open field data](https://orvik.app/data/) page, with each source's licence terms.

## Questions people ask about this

What bird lays plain blue eggs?

In North America, most likely an American robin — a saturated unmarked sky blue, 28 to 30 mm, in a mud-lined cup. Eastern bluebirds lay paler blue eggs around 20 mm in a cavity or nest box, and European starlings lay glossy pale blue eggs of robin size in a messy nest stuffed into a building cavity. Size and nest type separate all three quickly.

Is it illegal to keep a bird egg I found?

In the United States, yes, for almost any native species. The Migratory Bird Treaty Act makes it illegal to possess the eggs, nests or feathers of over 1,000 species without a federal permit, with no exception for something found on the ground. The unprotected species are the introduced ones — house sparrow, European starling and rock pigeon. UK and EU law is equivalent. Photograph it and leave it.

Will the parents abandon the nest if I touch an egg?

No. That belief is one of the most persistent myths in birdwatching and it is false: most birds have a limited sense of smell and do not detect handling. If an intact egg has fallen and the nest is reachable, putting it back promptly is the right thing to do. What does cause abandonment is repeated disturbance — visiting a nest again and again, or standing near it while the parents wait to return.

Can I hatch a wild bird egg I found?

Practically, no, and legally, not without a permit. Wild bird eggs need temperature held within a fraction of a degree, controlled humidity, and regular turning, and an egg that has cooled for more than a short period is usually no longer viable. Even licensed rehabilitators have low success rates. A hatchling that did survive would imprint on people and be unreleasable.

I found four blotchy eggs on my gravel driveway with no nest. What are they?

Almost certainly a killdeer. They lay four pointed, heavily blotched buff eggs directly on gravel with no nest material, on driveways, car parks and flat roofs, and the eggs are effectively invisible until you are standing over them. If a bird nearby is screaming and dragging a wing as though injured, that is the parent performing a distraction display and you are close to the nest. Mark the spot from a distance, route around it, and the young will leave within about a month.

What does a hatched eggshell look like?

It comes apart into two pieces, with the larger fragment forming a neat cap, because the chick cuts a ring around the broad end from inside. The membrane usually still lines it and there is no dried yolk. Parents then carry the shell some distance from the nest before dropping it, which is why hatched shells turn up in places with no nest above them. A crushed shell with yolk on it was predated instead.

There is one odd egg in a nest that does not match the others. Why?

A brown-headed cowbird, most likely. Cowbirds build no nest and lay in the nests of other species — greyish-white with dense brown speckling, usually larger than the host's own eggs and hatching first. It is nature working as designed, and in the United States the cowbird egg is protected too: removing it is illegal without a permit.

## Still not sure? Point a camera at it

A filter narrows birds down to a shortlist. Orvik reads the photo itself and names the species, with the look-alikes ranked underneath so you can check the call yourself.

- [Get Orvik free](https://orvik.app/app/)

## Keep reading on Orvik

- [What bird is this?](https://orvik.app/birds/what-bird-is-this/)

- [Identify this bird](https://orvik.app/birds/identify-this-bird/)

- [Bird call identification](https://orvik.app/birds/bird-call-identification/)

- [Feather identification](https://orvik.app/birds/feather-identification/)

- [Apps to identify birds](https://orvik.app/birds/app-to-identify-birds/)

- [Owl call identification](https://orvik.app/birds/owl-calls-identification/)

- [Animal track identification](https://orvik.app/animals/animal-track-identification/)

- [The Merlin bird app](https://orvik.app/birds/merlin-bird-app/)

## Other free Orvik tools

- [Which bird did this feather come from?](https://orvik.app/tools/feather-identifier/)
- [Whose droppings are these?](https://orvik.app/tools/animal-scat-identifier/)
- [What snake did I just see?](https://orvik.app/tools/snake-identifier/)
- [What kind of rock is this?](https://orvik.app/tools/rock-identifier/)
- [Which mineral is this?](https://orvik.app/tools/mineral-identifier/)
- [What gemstone is this?](https://orvik.app/tools/gemstone-identifier/)
- [What fossil is this?](https://orvik.app/tools/fossil-identifier/)
- [What berry is this, and can you eat it?](https://orvik.app/tools/wild-berry-identifier/)

## Where the data comes from

- [US Fish and Wildlife Service — Migratory Bird Treaty Act protected species list](https://www.fws.gov/law/migratory-bird-treaty-act-1918)
- [Cornell Lab of Ornithology — All About Birds species accounts](https://www.allaboutbirds.org/)
- [NestWatch — nest and egg identification](https://nestwatch.org/)
- [NestWatch — general nest and egg information](https://nestwatch.org/learn/general-bird-nest-info/)
- [GBIF — Global Biodiversity Information Facility](https://www.gbif.org/)
- [iNaturalist](https://www.inaturalist.org/)

---

HTML version: https://orvik.app/tools/bird-egg-identifier/
Structured data for this site: https://orvik.app/api/v1/openapi.json · https://orvik.app/llms.txt
Free to quote and reuse with a link back to the source URL above (CC BY 4.0).