10 Birds That Lay Blue Eggs (Why Does It Happen?)

Birds That Lay Blue Eggs

Whenever we talk about eggs, most people instinctively think of a white or buff-colored egg. And it makes sense; most birds do lay eggs in these colors. All the eggs that we consume are generally either white or buff.

However, did you know that some birds can lay a different colored egg as well? Say, blue or green or olive? Well, while most of these birds are wild, their list stretches quite long.

Here are the bird species that lay blue eggs:

  1. Bluebirds
  2. Finches
  3. Warblers
  4. Thrushes
  5. Starlings
  6. Blue Jays
  7. Crows
  8. Ravens
  9. Herons
  10. Egrets

In this article, we will talk about all these birds and explore what their clutch looks like.


1. Bluebirds

The bluebirds are a group of medium-sized passerine birds native to the Americas. Belonging to the true thrush family, the bluebirds have three individual species, all in the Sialia genus.

Now, we’ll look at all three bluebird species since all of them lay blue eggs.

Eastern Bluebirds (Sialia sialis)

The Eastern Bluebirds are a small North American thrush species.

These birds display sexual dimorphism, wherein the males have a blue head, wings, and back, with a brownish-red patch on their chest.

The females are duller in comparison and have a grey head and back, with touches of blue here and there.

Their breast is colored like the males but appears light orange. These birds are the largest of all three bluebirds.

Clutch size: 2-7 eggs
Description: generally pale blue eggs; rarely white

Western Bluebirds (Sialia Mexicana)

Western Bluebirds are the smallest members of the Sialia genus. Despite being smaller in size than the Eastern Bluebirds, these birdies look more or less similar, except for their throat patch.

Unlike the orange throat patch of Eastern Bluebirds, the male Western Bluebirds have a blue patch on their chest, while the patch on the females is grey.

Clutch size: 2-8 eggs
Description: pale blue and unmarked eggs; sometimes white

Mountain Bluebirds (Sialia currucoides)

The Mountain Bluebirds are the only bluebird species that lacks any orange coloration on their body. These birds display a significant sexual dimorphism.

The upper parts of the male’s body are covered in turquoise blue, while their lower parts are a slightly paler shade of blue.

On the other hand, the females have a grey head, chest, and back, with dull blue wings and tail.

Clutch size: 4-8 eggs
Description: pale blue or whitish eggs; rarely pure white in color


2. Finches

The true finches have a diverse family, with over two hundred species divided into fifty genera.

The birds belonging to this family are characterized by their short and stubby beaks, with the color of their plumage being mostly shades of brown and green.

In this section, we’re going to talk about all the finch species that lay blue eggs.

House Finch (Haemorhous mexicanus)

Endemic to the western parts of North America, the House Finches are a small finch species known for their rapid warbling calls.

These birds display sexual dimorphism in size and plumage. The males have a stockier body than their female counterparts and a rosy tint on their heads, chest, and belly. This tint gets brighter in the winter.

Other than the rosiness, both sexes appear almost the same and have a dull brown body with dark grey streaks all over.

Clutch size: 2-6 eggs
Description: pale blue with light speckles of purple and fine black

Cassin’s Finch (Haemorhous cassinii)

The Cassin’s Finches are an American finch species named after John Cassin, a curator at the Philadelphia Academy of Natural Sciences.

These finches have moderate-lengthed beaks and a forked tail. The males have a streaked brown back, wings, and tail, with a rosy tint on their head and underbody.

On the other hand, the females possess a dull brown body, with their underparts being heavily streaked.

Clutch size: 3-6 eggs
Description: pale greenish-blue with speckles of black and brown

Grey-capped Greenfinch (Chloris Sinica)

Also referred to as the “Oriental Greenfinch,” the Grey-capped Greenfinches are a finch species that breed in the Palearctic regions.

Both sexes of Grey-capped Goldfinches have a brownish-green body with yellow undersides, with the females have duller plumage than their male counterparts.

Clutch size: 3-5 eggs
Description: pale blue with light brown spots

American Goldfinch (Spinus tristis)

The American Goldfinches are species of migratory finches that breed throughout North America. Although these birdies share their name with the European Goldfinches (Carduelis carduelis), the two species are not related.

These finches are sexually dimorphic in their plumage. The females have an overall brown body, with darker upperparts and lighter underparts; you can notice a pale-yellow bib on their throat.

On the other hand, the breeding males have a striking yellow body with a black cap on their heads. During the winters, their plumage becomes dull and turns into a buff shade.

Clutch size: 2-7 eggs
Description: white with a pale bluish tint, unmarked

Lesser Goldfinch (Spinus psaltria)

The Lesser Goldfinch is a North American finch species considered the smallest true finch in the world.

Lesser Goldfinches are sexually dimorphic, with the males having bright yellow underparts, a faded black cap, black wings, and a tail. They also have a bold white patch on their wings and tail.

On the other hand, the females have an overall dull, olive-greenish body, with lighter underparts and dark streaks on their wings and tails. The juveniles take after their mothers.

Clutch size: 3-6 eggs
Description: unmarked, bluish-white in color

Lawrence’s Goldfinch (Spinus lawrencei)

Breeding almost exclusively in California, Lawrence’s Goldfinches are a small finch species named after George Newbold Lawrence, the famous American ornithologist.

These finches have a stubby body covered in pale grey or pinkish plumage. However, they do have a yellow rump and patches of yellow on their wing bars. Their tail is jet black with a white band on it.

There is some sexual dimorphism in these birds. The males have a black cap on their heads, which the females lack. They also have a paler body, while their female counterparts have a dull brown body.

Clutch size: 3-6 eggs
Description: generally white and unmarked; very rarely pale blue

Eurasian Bullfinch (Pyrrhula pyrrhula)

As their name indicates, the Eurasian Bullfinches are a species of bullfinch that breed in Europe and parts of temperate Asia.

Perhaps because of the difference in their location, the Eurasian Bullfinches look very different from the American finch species. They have a somewhat bull-like head (thus lending them the name “bullfinch”) and a bulkier body.

Both sexes have grey upper parts, with grey wings and tails lined with black. The major difference between them occurs in their underparts, with the males having rosy underparts and the females having a buff-colored underbody.

Clutch size: 4-6 eggs
Description: pale blue, with a reddish-brown molt


3. Warblers

The warblers are a family of tiny, vocal passerine birds that are known for their warbling calls.

There are over 400 distinct warbler species in the world, with their family later being divided into two diverse groups: The Old World and New World Warblers.

In this section, we’ll talk about the two common warbler species that lay blue eggs.

Yellow Warbler (Setophaga petechia)

Being the most widespread member of their genus, the Yellow Warblers are a warbler species that belong to the New World Warbler family.

Both sexes of these warblers are very similar to each other, except for the males in the breeding plumage, that have an overall bright yellow body.

Otherwise, females and non-breeding males have greenish-yellow bodies, with the females being slightly duller in appearance.

Clutch size: 1-7 eggs
Description: greenish or bluish-white eggs with dark splotches

Olive Warbler (Peucedramus taenitus)

Also referred to as “Ocotero,” the Olive Warbler is a monotypic warbler species that belongs to neither the Old World nor New World Warbler families.

These warblers are quite long-winged and display sexual dimorphism in their plumage. The males have a tawny head and breast and grey wings with a touch of olive green and white wing bars.

On the other hand, the females have a yellow head and breast, with the same grey body with olive-green wings.

Clutch size: 3-4 eggs
Description: bluish-white eggs with brown or olive marks at the large end


4. Thrushes

Thrushes are a family of medium-sized passerine birds that mainly inhabit densely wooded areas. There are 174 members in the thrush family that are divided into 19 different genera.

In this section, we will look at the thrush species that lay blue eggs.

Wood Thrush (Hylocichla mustelina)

Closely related to the American Robins, the Wood Thrush are a small species of North American thrushes.

Wood Thrushes are not sexually dimorphic, i.e., both sexes appear the same. Their neck and underparts are buff-colored with cinnamon-brown streaking on them.

On the other hand, their head, back, and wings are colored in a plain, duller shade of brown.

Clutch size: 2-4 eggs
Description: light blue or white eggs with brown splotches

Clay-colored Thrush (Turdus grayi)

Declared as the national bird of Costa Rica, the Clay-colored Thrushes are a central American thrush species that are popularly known as “Clay-colored Robins.”

These thrushes are referred to as robins due to the similarities between their appearances. They have an overall dull brown body with a faintly streaked throat and lighter underparts. Their flight calls are also similar to the robins.

Clutch size: 2-4 eggs
Description: light blue eggs with occasional reddish-brown splotching

Dusky Thrush (Turdus enormous)

The Dusky Thrushes are a strongly migratory thrush species that migrate all the way to Japan during winters.

These are stocky birds with dark faces and breasts. Their belly and undertail are white, while the rest of their body (back and rump) is dusky brown in color.

Clutch size: 3-5 eggs
Description: light blue or green eggs with pale brown splotches

White-throated Thrush (Turdus assimilis)

The White-throated Thrushes are medium-sized thrush species that commonly breed in Central America and Mexico.

These thrushes have a characteristic white throat with dark streaks running across them. They have a greyish brown back and a similarly colored breast, only lighter in the shade.

Clutch size: 2-4 eggs
Description: blue or white eggs with grey or reddish-brown flecks

Aztec Thrush (Ridgwayia Pinicola)

Primarily residing in the montane forests, the Aztec Thrushes are a thrush species mainly found in Mexico; these birds come to the United States as a rare vagrant.

Both sexes of the Aztec Thrushes appear similar, except the females lack the hood and are paler in the shade.

The males have a dark brown hood; their neck and upper parts are brown, too, but have heavy streaks all over them. Their backs are brownish, too, with their dark wings streaked by white and a dark tail.

Clutch size: 2-3 eggs
Description: light blue and unmarked eggs

Varied Thrush (Ixoreus naevius)

The Varied Thrushes are a large thrush species that are the monotypic members of the Ixoreus genus.

These thrushes are not sexually dimorphic; the females are slightly duller in appearance. They have an orange throat and breast with a dark face mask, back, and wings.

Their wings are streaked with orange. The face mask and throat patch of the males are darker in the shade than their female counterparts.

Clutch size: 1-6 eggs
Description: light, sky blue eggs, often unmarked; occasionally with reddish splotches

American Robins (Turdus migratorius)

One of the most widespread thrushes of North America, the American Robins are a migratory thrush species.

These birds have a yellow bill, brown back, and orangish breast. Both sexes appear similar, except the females have a slightly duller plumage.

Clutch size: 3-5 eggs
Description: unmarked, cyan-colored eggs


5. Starlings

The starlings are a large family of medium-sized passerine birds endemic to Asia, Africa, and Europe. Despite their nativity, these birds are found as invasive species in most parts of the world.

In this section, we will talk about the North American starling species that lay blue eggs. Interestingly enough, both these species are invasive on the continent.

Common Myna (Acridotheres tristis)

Also referred to as the “Indian Myna” due to their nativity, the Common Mynas are starling species endemic to Asia.

These birds are highly territorial and adaptable, which is how they’ve adapted to different climates and can now be found in almost every corner of the world.

Mynas have a dark brown body with a jet-black hood on their heads. They also have two bright yellow patches on their face, one behind each eye. Moreover, the color of their legs and bill matches this patch.

Both sexes are identical and display no sexual dimorphism.

Clutch size: 2-5 eggs
Description: unmarked, bluish-green eggs

European Starling (Sturnus vulgaris)

Popularly known as the “Common Starling” due to their widespread population, the European Starlings are a starling species that have originated in Europe. In the United States, they are an introduced species.

These starlings have an iridescent black plumage with touches of purple and green here and there. They also have white speckles all over their plumage that grow more remarkably as the temperature turns cold.

Both sexes appear similar, except the females are a duller shade of brown (almost greyish).

Clutch size: 4-5 eggs
Description: unmarked, pale blue, or green eggs


6. Blue Jay (Cyanocitta cristata)

Endemic to the eastern parts of North America, the Blue Jay is a large passerine bird species belonging to the corvid family.

These birds have a white face and underbody, with a bold, black marking on their throat. Their back, wings, and tail are all covered in a brilliant shade of turquoise blue.

Both sexes of blue jays display minimal sexual dimorphism and are almost alike, except the females are slightly smaller than the males.

Clutch size: 2-7 eggs
Description: light blue eggs with brown speckles


7. American Crow (Corvus brachyrhynchos)

The American Crows are large passerine birds belonging to the corvid family. These birds are one of the most widespread species in North America.

They’re purely black, including their eyes, beak, and legs. On their wings, these birds have an iridescent hue, making them shine in the sunlight.

Both sexes are similar, displaying sexual dimorphism in their size, with the males being the larger.

Clutch size: 3-9 eggs
Description: bluish-green to olive-green eggs with dark blotches at the large end


8. Common Raven (Corvus corax)

Also referred to as the “Western Raven,” the Common Ravens are large, black passerine birds like the crows, to which they’re closely related.

These birds are also completely black like the crows, but they’re larger and heavier than the former, making them rank among the heaviest passerines of the world.

Clutch size: 3-7 eggs
Description: blue, green, or olive eggs mottled with purplish-brown


9. Great Blue Herons (Ardea herodias)

The Great Blue Herons are known for being the largest member of the entire heron family, including the egrets and the bitterns. These birds are commonly found in North and Central America.

These herons display minimal sexual dimorphism, with males being slightly larger and appear almost identical.

Both sexes have slate-colored wings with a touch of azure blue, rusty-grey neck, brownish thighs, and a pair of black and brown stripes on their flanks.

Clutch size: 2-6 eggs
Description: pale blue eggs that grow paler with time


10. Great Egrets (Ardea alba)

Also referred to as “Common Egret” due to their widespread population, the Great Egrets are the largest egret species in the world.

These tall birds have an overall white plumage with yellow bills and black legs. However, in the breeding season, their bills turn darker and their legs lighter.

Additionally, they also grow fine, decorative plumes on their bodies in the breeding season. Both sexes are identical.

Clutch size: 1-6 eggs
Description: smooth and unmarked pale blue or green eggs


Factors responsible for the blue eggs of birds

Now that we’ve learned about different kinds of birds that lay blue eggs, don’t you feel a curiosity about why or how this happens?

Have you wondered if all birds are capable of laying colorful eggs? Or are these blue egg-laying birds special? What if we told you that we have the answer to your question?

The truth is various factors, both internal and external, play a vital role in deciding the color of a bird’s eggs. In this section, we are going to talk about all these factors:


Camouflage is an age-old skill or ability used by both humans and animals to blend themselves with their background to prevent a threat.

Therefore, it shouldn’t be surprising that camouflage would be a factor impacting the color of a bird’s eggs.

However, the blue-colored eggs have nothing to do with camouflage since they’re a shade that doesn’t blend with their surroundings.

Temperature control

The color of an egg plays a key role in its resistance to heat and UV radiation from the sun.

The darker eggs can heat up quickly but have better UV protection. On the contrary, a light-colored egg will insulate heat to some extent but is more exposed to UV radiation.

Because of it, the birds that have more open nests usually lay light-colored eggs, while those with a well-sheltered nest will lay darker eggs.

Nesting patterns

When the eggs are lying in a bird’s nest, it’s the parents’ responsibility to protect them.

Applying camouflage to this fact would mean that the birds that lay darker eggs can stay away from their nests for longer periods.

On the other hand, those with light-colored eggs must stay close at all times to protect their eggs from outside threats.



In this article, we learned about the common birds that lay blue colored-eggs, including the finches, thrushes, corvids, and wading birds.

Additionally, we also discovered the factors that contribute to the color of an egg. The next time you spot an unusual blue egg in your yard, you’ll know exactly which bird it belongs to.