Eggshells are comprised of calcium carbonate, hence the default color of eggs is plain white. It’s through the addition of pigments that avian eggs gain their range of colors, hues, and patterns.
Although not the most common color, many bird species lay blue eggs. This is the result of a pigment called biliverdin which produces blue and green hues. Below is a list highlighting some of the birds that lay blue eggs.
List of Birds That Lay Blue Eggs
From blue feet caused through their diet of fish to boasting a colorful plumage, each avian species in this list differs greatly, from their morphology to their behavior. Despite this, all of them lay blue eggs which can be either speckled or plain.
American Goldfinch

Scientific Name: Spinus tristis
The American goldfinch boasts a bright yellow body, black forehead, and black wings with white patches. During the winter months, the yellow feathers become light brown.
This bird builds its nests hidden away in shrubs. The female lays between 2 and 7 light blue-colored eggs.
Their small, conical beak aids its granivore diet, favoring thistle, and sunflower seeds, which they search for on the ground of forests and gardens.
These birds are distributed throughout North America.
American Robin

Scientific Name: Turdus migratorius
The American robin is so-called due to their distinctive red breast. The rest of their feathers are a brown-grey color, except the underbelly which is white. They average around 10 inches long.
Their diet consists of fruit and berries alongside small invertebrates, for which they forage on the ground.
They build cup-shaped nests in various habitats including woodland, farmland, and urban areas. Clutches consist of between 3 to 5 eggs light blue eggs.
They are distributed throughout North and Central America, from Canada to Northern Mexico.
Blue Finch

Scientific Name: Porphyrospiza caerulescens
As the name suggests, males boast an indigo-blue plumage with a conical yellow bill. Females however are brown in color. Blue finches lay 4 to 6 blue eggs in a clutch.
Their diet includes both plant matter and invertebrates and they are often seen foraging on the ground for them.
Blue finches are localized in Bolivia and Brazil as they favor dry savanna habitats.
Blue Jay

Scientific Name: Cyanocitta cristata
This species possesses a light blue plumage with a white face and belly. Black stripes adorn the wings and tail. Females lay eggs that are light blue and coated in brown speckles.
Their strong black beak is used for cracking open nuts, which comprise a large part of their diet. Although they feed mainly on plant matter, they also consume small invertebrates.
They are distributed from Southern Canada to Central America. They favor habitats at woodland edges over central ones with dense vegetation.
Blue-Footed Booby

Scientific Name: Sula nebouxii
As implied by the name, this species has bright blue webbed feet. Its head and underside are white whilst its wings are brown. Boobies do not make nests but lay 2 to 3 pale blue eggs on the bare ground. This is a large bird reaching up to 32 inches in length.
Being a marine species, it’s a piscivore feeding on fish and also squid. Their iconic blue feet get their color from the carotenoid pigment in the fish they consume.
They are located along the Eastern Pacific coasts from California to Peru and even the Galapagos Islands.
Dunnock

Scientific Name: Prunella modularis
Dunnocks somewhat resemble house sparrows due to their brown plumage. This coloration has likely evolved as a mechanism to avoid predation by being inconspicuous.
Females lay 4 to 5 blue eggs in nests that they build in shrubs close to the ground.
They are found throughout Europe, spilling into Asia and Russia. They inhabit vegetated areas.
Eastern Bluebird

Scientific Name: Sialia sialis
Males boast a bright blue head, back, and wings with a red-brown breast. Females adorn a grey head, back, and wings with an orange-brown breast. Females construct cup-like nests in which they lay 3 to 7 light blue eggs.
They feed mainly on invertebrates though they also consume wild fruit and berries.
As their name suggests, they inhabit Southeast America.
Eurasian Blackbird

Scientific Name: Turdus merula
Males have a glossy black plumage whilst their female counterparts adorn a sooty-brown plumage. Both have bright yellow bills. Their blue eggs are coated in red-brown spots.
They are omnivores feasting on anything from worms to fruit.
Blackbirds are widely distributed, inhabiting Europe, Russia, North Africa, Australia, as well as New Zealand.
European Starling

Scientific Name: Sturnus vulgaris
European starlings have a black plumage speckled with iridescent purple and green spots. Females lay pale blue eggs. The European starling is also called the common starling.
Being omnivores they feast on insects and vegetation.
They are native to Eurasia and migrate southwards during the harsh winter.
Goldfinch

Scientific Name: Carduelis carduelis
Goldfinches have a bright red face and a chestnut brown back. Their wings are black with a bright yellow stripe adorning them. Females lay between 4 and 6 pale blue eggs with red-brown speckles.
Primarily, they feast on seeds as their long, thin beak is adapted for extracting seeds from plants, especially thistles.
Goldfinches are native to Eurasia and North Africa, favoring habitats containing many seeding plants.
Gray Catbird

Scientific Name: Dumetella carolinensis
Grey catbirds appear almost entirely pale grey except under the tail which is rust-colored. Females lay between 2 to 6 dark blue eggs.
They feast on arthropods but primarily on fruit, which they forage for amongst the leaf litter in semi-open habitats.
They are native to North America and migrate Southwards during the winter.
Great Blue Heron

Scientific Name: Ardea herodias
The great blue heron reaches 54 inches in length and has a wingspan of 79 inches. They have grey feathers with black and white faces. Their long, pointed, yellow beak is perfect for snatching fish from the water, whilst wading perched on their long legs.
Herons are widespread throughout most of North America and inhabit a variety of wetlands from swamps to shorelines.
Females lay their blue-green eggs in nests located high in trees.
Great Tinamou

Scientific Name: Tinamus major
These birds can weigh just shy of 3 lb and reach 17 inches in length, with their morphology somewhat resembling a pheasant. The plumage is brown-grey with a white throat and belly.
Being a polygynandrous species, the males incubate the bright blue eggs until they hatch.
Great tinamous are located in tropical and subtropical forests where they nest near the base of trees.
House Finch

Scientific Name: Haemorhous mexicanus
House finches are brown and the males boast a red head and chest. The intensity of the red varies seasonally and is a result of the berries they eat.
They build cup-shaped nests in cavities in which females lay clutches of blue eggs with black spots.
These birds inhabit both urban and suburban areas across North America.
House Sparrow

Scientific Name: Passer domesticus
Both sexes are brown and grey, but males are more vibrant and have additional white markings. These monogamous pairs raise their chicks in nests built in cavities. Their eggs are white-green and coated in grey speckles.
They are a social and gregarious species that feed opportunistically on insects and seeds.
House sparrows are strongly associated with human urbanization and activity, inhabiting many man-made structures. Originating from the Middle East but are now abundant in every continent except Antarctica.
Lesser Goldfinch

Scientific Name: Spinus psaltria
Measuring less than 5 inches in length, the lesser goldfinch is the smallest of the finch species.
Males have a bright yellow chest and belly and their back-plumage ranges from solid black to olive-green patches. Females however are olive-green with dull yellow underparts. Their eggs are pale blue.
Their diet consists primarily of seeds, favoring those from the sunflower family. They are often seen flocking around bird feeders.
They range from the Western US to South America and inhabit most areas except dense forests.
Mountain Bluebirds

Scientific Name: Sialia currucoides
As their name suggests, males boast a vibrant blue plumage. Females, however, are mostly grey, adorning a pale blue wing and tail stripe. They form monogamous pairs and raise their young which hatch from pale blue eggs.
Their diet is predominantly arthropod based during summer whilst over winter they feed mainly on berries.
Mountain bluebirds are located across North America and prefer to inhabit open environments at high elevations.
Red-Winged Blackbird

Scientific Name: Agelaius phoeniceus
Inferred through their name, this species has black feathers with a bright red and yellow patch on their wings. They produce pale blue eggs with dark brown markings.
Larger, brighter wing spots are correlated with higher mating success. Their diet consists of a variety of insects and seeds.
They are ubiquitous across North America and inhabit wetlands, living in both freshwater and saltwater marshes.
Snowy Egret

Scientific Name: Egretta thula
Snowy egrets have entirely white plumage with a long, black bill and legs and yellow feet and lores. They can reach 26 inches in length. Males begin building nests in trees in which an attracted female will lay up to 6 blue eggs.
Their diet consists of aquatic organisms such as fish, crustaceans, and insects which they stalk in shallow water.
They are native to North, South, and Central America where they live in wetlands ranging from marshes to rivers.
Song Thrush

Scientific Name: Turdus philomelos
Song thrushes have brown upperparts and white underparts adorned with brown speckles. They lay pale blue eggs that have large brown spots.
Living up to its name, they produce loud, repeating songs. Song thrushes are omnivores but are known for eating snails which they obtain by smashing the shells against rocks.
They are most abundant throughout Europe and nest in habitats with plentiful undergrowth.
Wood Thrush

Scientific Name: Hylocichla mustelina
The upper parts of wood thrushes are chestnut-brown whilst the underparts are white and have brown spots.
They are a solitary species and feast primarily on invertebrates found in the soil. Monogamous pairs nest within dense vegetation and lay between 2 and 4 blue eggs.
Their range extends through Eastern US and they migrate to Central America over the winter months via celestial navigation.
Why not read Do Birds Get Pregnant? and learn how birds reproduce?
Why Do Birds Have Blue Eggs?
Some scientists believe the blue pigment has biophysical benefits. It strikes a balance between the heating up of an egg and the absorption of ultraviolet radiation into the embryo.
Birds that lay eggs in open areas that are often exposed to sunlight have lighter-colored eggshells, such as Great Blue Herons which nest high in trees.
Other experts believe that blue pigmentation allows the eggs to be easily spotted by the parents to avoid damaging them. These species don’t need to worry about camouflage since they nest in cavities, such as house sparrows.
Moreover, eggshell pigments can be used to identify the bird’s health, parental care strategies, and identify brood parasites.
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