Eggs are usually described to be white or brown, so it may come as a surprise once you learn that there are birds that lay blue eggs. Just as diverse as the animal kingdom can be, so would the colors of these eggs.
From pale to greenish-blue eggs, these striking hues had captivated the interest of many. The good news is you won’t have to wait and observe what bird flies back to the blue-egged nest to determine the species.
In this article, we will get to know 40 birds that lay blue eggs in greater detail. Discover what they look like, their characteristics, and more. Keep reading!
What Birds Lay Blue Eggs?
1. Blue Jay
| Incubation Period: | 17 – 18 days |
| Egg Size: | 0.7 – 0.9 inches (width) 1.0 – 1.3 inches (length) |
| Clutch Size: | 2 – 7 eggs |
| Number of Broods: | Up to two broods in a year |
The Blue Jay is noted for its white, black, and blue plumage and its small, blue eggs. These are adorably minute and speckled in grey or brown spots.
Initially, they may appear more greenish but turn blue later on. They’re well-protected by a secured nest, which Blue Jays usually build around February.
Unfortunately, no matter how much nests are protected, Blue Jays’ eggs are still at risk of getting targeted by predators, such as snakes, crows, cats, and squirrels.
Hence, Blue Jays try to lay their eggs in the middle of green trees or shrubs to conceal their nests.
Due to these birds’ territorial nature, leaving their lofty nest alone is best done if you happen to find them. You might think it has been abandoned if the female or mother bird isn’t there, but it’s typically not part of the bird’s behavior.
2. American Robin
| Incubation Period: | 12 – 14 days |
| Egg Size: | 0.8 inch (width) 1.1 – 1.2 inches (length) |
| Clutch Size: | 3 – 5 eggs |
| Number of Broods: | Up to three broods in a year |
The American Robin is common throughout the United States, and it is another species that produces blue eggs. What causes their eggs to have the blue pigment is the biliverdin.
This is deposited on the eggshells while American Robins lay their eggs. The intensity of the color will range from bold blue and icy blue to pale.
The reason American Robin bird eggs are blue is to protect the embryos from harsh ultraviolet (UV) rays.
During one of my studies involving the diet of captive American Robins, my team tried to look into how food affects the quality of the eggs these birds produce.
We divided them into two sets, and gave one set top grade bird food with a good mix of fruits, and the other one, just average grade, yet still considerably healthy bird food. It was remarkable to note that those given the best nutrition tend to produce darker-colored eggs.
On the other hand, American Robin with a less nutritious diet ended up having lighter-colored eggshells.
Meanwhile, other independent findings for American Robin eggs indicate that those produced earlier in a brood come in a more intense blue color compared to those that came later. Further, it is also noticed that smaller eggs have deeper colors than larger ones.
3. Starling
| Incubation Period: | 12 days |
| Egg Size: | 0.8 – 0.9 inches (width) 1.1 – 1.3 inches (length) |
| Clutch Size: | 4 – 6 eggs |
| Number of Broods: | Up to two broods in a year |
Another blue egg-producing avian species is the Starling bird, known for its distinct yet aesthetic-looking feathers. Despite being such a small bird, it can produce up to six eggs, albeit in very small sizes.
They appear in different shades of blue with no markings or speckles around them. Sometimes, a few eggs may display a greenish hue compared to the rest of the brood. They’re also glossy and short to long oval in size.
Starlings place these eggs inside tree cavities or use spaces of old or abandoned houses. One remarkable habit they have is to breed in the same nest where they previously produced their eggs.
That is unless the place was destroyed or deemed unsafe if many predators live nearby.
Also, contrary to other avian species wherein only females incubate their eggs, male and female Starlings take on the task.
4. Red-Winged Blackbird
| Incubation Period: | 11 – 13 days |
| Egg Size: | 0.6 – 0.8 inches (width) 0.9 – 1.1 inches (length) |
| Clutch Size: | 2 – 5 eggs |
| Number of Broods: | Up to three broods in a year |
A Red-Winged Blackbird’s blue eggs come in beautiful abstract designs. These eggs display a blue color with black hues splattered around them to describe their appearance even more.
Mostly, however, these eggs are seen to be greenish-blue, complemented by brown markings. At times, they’d even appear grey with black patterns all over. These are all kept safe in a nest shaped like a cup.
On another note, Red-winged Blackbirds commonly live near water sources like marshlands, and they’re not far from the other nests of their relatives. This is explained by their strong familial bonds.
Further, male and female Red-Winged Blackbirds prefer using the same spot every mating season, which lasts from May to June.
Fun fact, these birds are polygynous, and a male Red-Winged Blackbird can have up to 15 partners during the mating season. Many nests are expected to be built and seen, especially in Northern America.
5. Dunnock
| Incubation Period: | 12 – 13 days |
| Egg Size: | 0.6 inch (width) 0.7 inch (length) |
| Clutch Size: | 3 – 6 eggs |
| Number of Broods: | Up to three broods in a year |
The Dunnock, also known as the Hedge Sparrow, is quite similar in looks to House Sparrows thanks to its brown plumage, but what makes it distinct from the others are its bright blue eggs.
As small birds, they can only lay up to six eggs in incredibly small sizes. These eggs are mainly turquoise, with tiny black or brown specks.
You can find them in hollow nests structured firmly for their protection. Although well-concealed, the nest is still at risk of getting attacked by predators, mainly because the blue-colored eggs are highly attractive and easily spotted.
It’s usually the first brood of Dunnocks that gets preyed on. The chance of losing the bird’s young is even higher if it is its first-ever nest.
Meanwhile, here’s a short video showing what a Dunnock’s nest looks like with its blue eggs in it:
6. Blue-footed Booby
| Incubation Period: | 41 – 45 days |
| Egg Size: | 1.88 inches (width) 2.44 inches (length) |
| Clutch Size: | 1 – 3 eggs |
| Number of Broods: | Up to two broods in a year |
The Blue-Footed Booby is a rare seabird that lays blue eggs. It’s known for its long and pointed beak and the pronouncedly blue webbed feet. The bluer the feet, the more attractive in their world.
Once they lay eggs, the color palette may range from green to light blue. Each partner must take turns guarding these eggs while the other keeps a watch for predators.
Since the Blue-Footed Booby lacks a brood patch, it uses its feet to incubate its light blue eggs. It’s interesting since it can lay up to three eggs per brood.
Once the eggs have hatched, the female Blue-Footed Booby takes over the nest. Meanwhile, the male partner goes out looking for food to feed the young.
It’s also worth noting that they’re extremely faithful and monogamous to their partners.
7. Great Tinamou
| Incubation Period: | 17 – 19 days |
| Egg Size: | 2.02 inches (width) 2.3 inches (length) |
| Clutch Size: | 2 – 12 eggs |
| Number of Broods: | Up to two broods in a year |
The widely popular native birds of South America, or the Great Tinamou, produce colorful, smooth, and shiny eggs in turquoise, violet, green, and even pink.
The nanostructure coloration is responsible for the colored shades of these birds’ eggs. The common color would be blue, and you’d be lucky to see other colors aside from that.
Since Great Tinamous don’t build their nest in high places, their eggs can be seen standing out on the ground. One way for them to hide these valuable eggs is by covering them with leaves and green grass.
Male Great Tinamous are in charge of intermittently incubating and protecting these eggs. However, it has been observed that their nests are at high risk of predation if they are visited often.
This is because predators observe and track down Great Tinamous, especially during the breeding season.
8. Common Myna
| Incubation Period: | 17 – 18 days |
| Egg Size: | 0.86 inch (width) 1.21 inches (length) |
| Clutch Size: | 4 – 6 eggs |
| Number of Broods: | Up to three broods in a year |
The Common Myna is a blue-egg-producing bird that can be found across Australia’s east and southeast coasts. It’s originally from southern Asia, and its population thrives, especially in cities and suburbs.
Although they are most noted for their turquoise eggs, they may also come in shades like greenish blue and exhibit brown spots around them.
With the Common Myna’s presence in several areas in various countries, their ability to produce up to six eggs, and having around three broods in a year, their numbers are rising exponentially.
In India, Common Mynas are deemed invasive. They’re territorial and aggressive regarding habitat areas, forcing other birds out from their nests, including their eggs.
However, one admirable trait of the Common Myna is that it pairs for life. Once they find their partners, they become inseparable. They’ll continuously breed during the mating seasons and work as a team in taking their young.
9. Blue-gray Gnatcatcher
| Incubation Period: | 11 – 15 days |
| Egg Size: | 0.4 – 0.5 inches (width) 0.5 – 0.6 inches (length) |
| Clutch Size: | 3 – 5 eggs |
| Number of Broods: | Only one brood in a year |
The Blue-Gray Gnatcatcher is a native of North America that, despite its small size, can produce up to five blue eggs in a brood.
Their eggs are easily identifiable since they come in a bluish-white shade with reddish-brown dots around them. They are laid comfortably in a nest made from fibrous materials, silk, or spider webs.
Typically, Blue-gray Gnatcatchers can be seen in dense forests. They can be heard performing their nasal songs, earning the “Little Mockingbird” nickname.
Even though they’re not sizable birds, they still possess an overprotective instinct when it comes to the safety of their young. The common big predators they may have to deal with are the Jays and Woodpeckers.
On a different note, Blue-gray Gnatcatchers are non-migratory birds. Thus, they prefer to stay in one place their entire life.
10. Gray Catbird
| Incubation Period: | 12 – 13 days |
| Egg Size: | 0.5 – 0.6 inches (width) 0.9 – 1.0 inches (length) |
| Clutch Size: | 1 – 6 eggs |
| Number of Broods: | Up to three broods in a year |
The Gray Catbird is known for its distinctive voice and turquoise-green eggs, which it produces in well-built nests around 4 to 60 feet off the ground.
These eggs may have small red spots around them, which help in confirming that they indeed belong to a Gray Catbird.
The pigment exhibited in the eggs’ outer covering helps protect the yolk from direct sunlight, especially if they’re located in high places.
Usually, though, the nest of Gray Catbirds can be seen in shrubs, vines, and small trees.
Aside from being known to lay vibrant-looking bird eggs, Gray Catbirds are notorious for destroying other birds’ nests. They either consume the yolks or prevent the breeding of the brood parasite.
During the observation, they mostly targeted nests belonging to brown-headed Cowbirds instead of conspecific eggs.
11. House Finch
| Incubation Period: | 13 – 14 days |
| Egg Size: | 0.5 – 0.6 inches (width) 0.6 – 0.8 inches (length) |
| Clutch Size: | 2 – 6 eggs |
| Number of Broods: | Up to three broods in a year |
The House Finch is a common sight in North America, and it is a red-headed songbird with light bluish-green eggs. A few black and lavender spots are dotted around them.
House Finches nest near ground level for the eggs’ protection, mainly in a cavity or an aperture. They first ensure that the place is away from predators like squirrels and snakes.
As monogamous birds, you can expect house finches to pair for life. By the time the mating season starts, most birds of this species have already found their pair.
They don’t find noisy environments bothersome, so they’re not picky when choosing where to nest. On another note, there are occasions wherein House Finches may use an abandoned bird’s nest.
12. Song Thrush
| Incubation Period: | 13 – 15 days |
| Egg Size: | 0.86 inch (width) 1.22 inch (length) |
| Clutch Size: | 3 – 5 eggs |
| Number of Broods: | Up to three broods in a year |
The blue eggs of a Song Thrush are eye-catching as they come in a pale shade with a few large speckles, mainly on the wider end. These medium-sized birds are relatively shy and rarely leave their cover.
Part of the reason they prefer being near their desired location is their territorial tendencies. Still, they occasionally leave their nest to gather food for their young.
Typically, the nest that holds their blue eggs is built in ivy, old buildings, or tree trunks. These are made from leaves, twigs, moss, and roots, plus they’re durably lined with mud to form a neat cup.
Although only female Song Thrushes build their nests, their partners usually help feed and tend the young until they leave the nest after 12 to 15 days.
13. Varied Thrush
| Incubation Period: | 12 days |
| Egg Size: | 0.8 – 0.9 inches (width) 1.1 – 1.4 inches (length) |
| Clutch Size: | 1 – 6 eggs |
| Number of Broods: | Up to two broods in a year |
Deep into the mature forests of the Pacific Northwest lay several sky-blue eggs with brown speckles belonging to the Varied Thrush birds. These come around in March and April, their typical breeding season.
A female Varied Thrush is the one that chooses where to nest, and its usual choice is the understory of a dark, wet, and mature forest. Its ideal location is also one where other old nests are nearby.
The nest of sky-blue eggs is generally ten feet off the ground. Despite its high location, it still needs to be protected from getting predated since it’s mostly poorly concealed.
To describe the appearance of a Varied Thrush’s nest, this is weaved using fur, alder twigs, hemlock, and spruce. The female bird will then harden it using rotten wood, mud, moss, or decomposing grass.
The dense cup is generally two inches deep and lined with fine grasses and moss.
14. Linnet
| Incubation Period: | 10 – 14 days |
| Egg Size: | 0.51 inch (width) 0.70 inch(length) |
| Clutch Size: | 4 – 5 eggs |
| Number of Broods: | Up to three broods in a year |
Where there is a bountiful supply of seeds, expect a Linnet and its nest of blue eggs to be close by.
These birds prioritize having an abundant food source like bird feeders nearby since they mainly consume seeds throughout the year.
Before female Linnets start producing their eggs, their male mates protectively guard them to prevent others from trying to mate with their partners.
After breeding, Linnet eggs are mainly identified through their pale blue color. They may have brown or purple dots all over.
The Linnet’s favorite nesting site are thorn bushes, particularly the gorse bushes. The nests they build are mainly made from roots, stems, and grass, lined with feathers and hairs.
Unfortunately, due to a change in agricultural practices, Linnets are declining. Nest failure is one of the consequences of losing their preferred foraging ground.
15. Blackbird
| Incubation Period: | 13 – 14 days |
| Egg Size: | 0.86 inch (width) 1.14 inches (length) |
| Clutch Size: | 3 – 5 eggs |
| Number of Broods: | Up to four broods in a year |
The Blackbird features an all-black plumage with orange beaks and eye rims. The blue eggs of these birds can look greenish blue or completely blue with many brown freckles.
How Blackbird nests appear is similar to that of Thrush birds since they are made up of twigs, plasters of mud, and fine grass and moss lining. Further, these birds prefer to nest low on the ground.
Some areas they choose are shrubs, small trees, and climbing plants. Although they may take advantage of other natural structures to improve their nests’ durability, most Blackbirds can’t do so.
This is even more the case if it risks their safety. Regarding their brood, Blackbirds can have up to four, and they will practically reuse their old nests to accommodate the young chicks.
16. Eastern Bluebird
| Incubation Period: | 13 – 20 days |
| Egg Size: | 0.6 – 0.8 inches (width) 0.7 – 0.9 inches (length) |
| Clutch Size: | 4 – 5 eggs |
| Number of Broods: | Up to three broods in a year |
The Eastern Bluebird is a small bird with mostly blue upper parts, an orange chest, and white underbellies. They are obligate cavity nesters, which means they nest only in a cavity, chamber, or the like to ensure their blue eggs are well-protected.
Most of the time, Bluebirds will utilize cavities made by woodpeckers. On rare occasions, they may also opt for gutters or nest boxes. If you find one, around 4 to 5 blue bird eggs can be seen, and they’re mostly blue, but some can be white.
Around March and late April, typical Eastern Bluebirds start building their nests. The nest takes approximately 5 to 6 days to finish. This is an open cup with a coarse texture. The lining is filled with delicate fibers with feathers and occasional mammal fur.
Further, Bluebirds may have a behavior of building two nests. They may be located in one place, set reasonably apart from the cavity. Still, only one is used in producing eggs.
17. Snowy Egret
| Incubation Period: | 24 – 25 days |
| Egg Size: | 0.9 – 1.3 inches (width) 1.6 – 1.7 inches (length) |
| Clutch Size: | 3 – 4 eggs |
| Number of Broods: | Only one brood in a year |
Popular for its beautiful white plumage and long legs, the Snowy Egret is a type of heron that is also known to produce oval-shaped blue bird eggs shaded in greenish-blue.
These birds are mostly found in the United States, Canada, Argentina, and the West Indies. At some point, their numbers were on a decline caused by market hunters who went after their curving plumes.
Due to conservation efforts, the Snowy Egrets are back to becoming a common sight in the shallow coastal wetlands.
When these birds approach the mating season, their greenish-yellow feet turn orange-yellow. Their bare faces also turn from yellow to reddish.
During one of my birdwatching adventures in Canada, I got the opportunity to observe Snowy Egrets in their natural habitat. It was also a good time since that was the period when they started producing their brood.
What captured my attention was that as both sexes took turns incubating the blue eggs, they had this unusual behavior of passing the other a stick like a baton. Further, both male and female Snowy Egrets take care of the young when they hatch.
18. Green Heron
| Incubation Period: | 19 – 21 days |
| Egg Size: | 1.1 – 1.4 inches (width) 1.3 – 1.7 inches (length) |
| Clutch Size: | 2 – 6 eggs |
| Number of Broods: | Up to two broods in a year |
The Green Heron is a common breeder in inland and coastal wetlands and lays blue-green to pale-green eggs. These are carefully placed in nests located on or over the water.
Some may also be found around 30 feet off the ground or higher. These nests are built on sites such as cedar, hickory, and mangroves. Moreover, males initially build these breeding grounds before even pairing.
The rest of the nest construction is passed on to their mates. Female Green Herons shape it, and the structure may vary from solid to flimsy. They may even renovate old nests or refashion them.
Once the eggs have hatched, they typically stay with their parents for one month after leaving the nest. This is when they take their time learning how to forage.
To protect their feeding area, Green Herons constantly drive away other species.
19. Great Blue Heron
| Incubation Period: | 27 – 29 days |
| Egg Size: | 1.8 – 2.0 inches (width) 2.4 – 3.0 inches (length) |
| Clutch Size: | 2 – 6 eggs |
| Number of Broods: | Up to two broods in a year |
The Great Blue Heron, known for its protruded crest and long legs, also produces light blue eggs that turn white during incubation. These attractive Great Blue Heron eggs are found in nests located in trees, ground, bushes, mangroves, and other structures.
Once the mating season starts, a colony of male Great Blue Herons settles on the nesting sites and court females that pass by. They will present the gathered nest materials, usually vegetation, such as saltgrass.
Male Great Blue Herons will undergo a difficult process of courtship and rituals. When the female accepts its offer, it will craft a nest in preparation for its eggs. The building may take around three days to two weeks.
On a different note, Great Blue Heron pairs are monogamous throughout the breeding season. However, they change partners each year.
20. Mountain Bluebird
| Incubation Period: | 18 – 21 days |
| Egg Size: | 0.6 – 0.7 inches (width) 0.8 – 1.0 inches (length) |
| Clutch Size: | 4 – 8 eggs |
| Number of Broods: | Up to two broods in a year |
Despite the proportions of a Mountain Bluebird, it’s impressively capable of producing up to eight pale blue eggs in a brood. They’re shiny and usually bear no freckles or markings around them.
These pale blue eggs are looked after in nests made by female Mountain Bluebirds. The male partners may mime the act of bringing nesting materials, but in reality, all the work is done mostly by females.
The cavity is gradually insulated by coarse, dry grass stems and other vegetation available until a cup is formed, large enough to accommodate its blue bird eggs.
In the post-breeding season, more and more fledglings become independent, and they are joined by adult Mountain Bluebirds that failed to reproduce that year.
The Mountain Bluebird flock will visit the remaining fledglings on the nest, but only in a few hours or days until they entirely disappear from the territory.
21. Little Blue Heron
| Incubation Period: | 22 – 23 days |
| Egg Size: | 1.2 – 1.4 inches (width) 1.6 – 2.0 inches (length) |
| Clutch Size: | 3 – 4 eggs |
| Number of Broods: | Only one brood in a year |
The Little Blue Heron has dark plumage all over, and it lays pale blue-green eggs. This bird is commonly found nesting and foraging in swamps, ponds, marshes, and lagoons, to name a few.
Females find locations like shrubs and small trees ideal for their nesting. Since their blue eggs stand out in the environment, it’s a priority to ensure they’re away from predators.
Hence, flooded areas or islands are two of their preferred breeding spots. Female Little Blue Herons would take 3 to 5 days to finish making their nests.
These are constructed using leafless twigs lined with greener vegetation. The nesting materials are gathered by the male, and the female is in charge of building the bulk of the nest.
When it comes to incubation, both sexes perform the task. Once the pale blue-green eggs hatch, the younglings appear covered by a sparse white down with partially open eyes.
22. Blue Grosbeak
| Incubation Period: | 11 – 12 days |
| Egg Size: | 0.6 – 0.7 inches (width) 0.8 – 0.9 inches (length) |
| Clutch Size: | 3 – 5 eggs |
| Number of Broods: | Up to two broods in a year |
The Blue Grosbeak bird is among those that lay tiny eggs that come in light blue to bluish-white. They come unmarked and freckles-free. However, there may be times when they bear brown spots around them.
Pairs work together to build a nest for these blue eggs. They’re serially monogamous the entire breeding season and share nesting tasks like a team.
Female Blue Grosbeaks incubate all eggs while the males feed their partner the entire time. Since they’re mainly carnivores (insectivores), Blue Grosbeaks can be seen feeding on insects, snails, and spiders.
Seeds and grains may also be part of their diet. Meanwhile, female Blue Grosbeaks will keep feeding their young once the incubation period is through. This is done until they’re ready to fledge and leave the nest.
If female Blue Grosbeaks start building a second nest too early, the males will continue feeding their chicks.
23. Bluethroat
| Incubation Period: | 13 – 14 days |
| Egg Size: | 0.51 inch (width) 0.78 inch (length) |
| Clutch Size: | 5 – 7 eggs |
| Number of Broods: | Up to two broods in a year |
The Bluethroat is found across Asia, Europe, and western North America, and it produces very small blue or bluish-green eggs with several fine reddish specklings.
Their nests are usually found in their common habitat: the thickets, bushy areas, mountainous areas, and scrubs on hills. These are commonly near a water source, too.
Meanwhile, Bluethroats nestle in low, dense vegetation areas, especially when it’s nesting season.
It’s the female Bluethroat’s responsibility to construct the nest. Typically, it’s made from grass, roots, moss, and bark. Animal hair is used, too, when available and is placed as a soft lining for the nest.
Once the incubation period is over and all of the bird’s eggs laid have hatched, the chicks leave the nest after 13 to 14 days.
Should females start the second brood early, the males will care for the first younglings alone.
24. American Crow
| Incubation Period: | 16 – 18 days |
| Egg Size: | 1.0 – 1.2 inches (width) 1.0 – 1.2 inches (length) |
| Clutch Size: | 3 – 9 eggs |
| Number of Broods: | Up to two broods in a year |
An American Crow is noted for its black plumage, eyes, and beak. Yet, out of this monochrome appearance, these birds can produce dull blue-green to gray-green eggs with blotches of gray and brown toward the large end.
They hide their nests on a horizontal branch or in the crotch near the trunk of any tree. Evergreen trees are also a preference, while deciduous trees are their alternative when evergreens aren’t available.
In building their nests in preparation for the female bird’s egg production, both sexes contribute to bringing materials. Even their young birds from the previous year come and help as well.
Generally, the nest, measuring about 6 to 19 inches across, comprises medium-sized twigs. It’s then lined by weeds, pine needles, soft bark, and animal hair when available.
25. Wood Thrush
| Incubation Period: | 13 – 14 days |
| Egg Size: | 0.7 – 0.8 inches (width) 0.9 – 1.1 inches (length) |
| Clutch Size: | 3 – 4 eggs |
| Number of Broods: | Up to two broods in a year |
Another bird whose eggs are described to come in a turquoise-green color with no markings is the Wood Thrush. They’re known for their rust-brown upper parts, white underparts, and black spots from the sides and breasts.
In making their nests, female Wood Thrushes may take 3 to 6 days to complete the construction. They start by securing a platform made from leaves, stems, dead grass, plastic, and paper.
The same materials are used in building the walls, and they use their whole weight to form a cup. The nest is then lined with mud and smoothed out using its breast. To bed the turquoise-green eggs, rootlets are used.
On a side note, although Wood Thrushes produce up to two broods each year only, these birds may need 3 to 4 attempts to do so.
26. Blue Mockingbird
| Incubation Period: | 12 – 13 days |
| Egg Size: | 0.6 – 0.8 inches (width) 0.8 – 1.2 inches (length) |
| Clutch Size: | 2 – 6 eggs |
| Number of Broods: | Up to four broods in a year |
The Blue Mockingbird is also one of the birds that lay blue-green eggs. These are spotted all over. Although these birds are endemic to Mexico, they are also seasonally found in the United States.
Their usual habitats are shrubs and woodlands. However, these birds from Mexico can be found near sea levels up to 10,000 feet in the mountains. Regardless of their location, they always prefer places near water sources.
When it’s time to build nests, male Blue Mockingbirds choose the nesting site. They then build several nests, and the females can choose which among these is best to lay their eggs.
In normal circumstances, female Blue Mockingbirds may start laying their next brood on the second nest. The males must take care of the first chicks until they are ready to fledge.
These younglings leave the nest 11 to 13 days after they hatch.
27. Swainson’s Thrush
| Incubation Period: | 10 – 14 days |
| Egg Size: | 0.6 – 0.7 inches (width) 0.8 – 1.0 inches (length) |
| Clutch Size: | 1 – 5 eggs |
| Number of Broods: | Only one brood in a year |
Another variety of the Thrush bird is the Swainson’s Thrush which also lays blue to greenish-blue speckled eggs. The spots all over them come in brown or red.
Flocks of Swainson’s Thrush birds usually nest in forest understories, like in the thickets of shrubs or conifer saplings, around 3 to 10 feet off the ground.
Their small blue eggs are laid comfortably on the construction of a combination of plants. Swainson’s Thrush birds usually use willow, fir, maple, rose, and oak.
These nests are built solely by the female Swainson’s Thrush, which takes about four days to complete. This variety makes the nest cup by thrusting their breasts and feet into it and snuggling inside it.
A new nest is built each season, and another brood is raised. Once all blue eggs laid are hatched, both parents feed them for 10 to 14 days before they start to fledge.
28. Eurasian Jackdaw
| Incubation Period: | 17 – 18 days |
| Egg Size: | 0.97 inch (width) 1.35 inches (length) |
| Clutch Size: | 2 – 9 eggs |
| Number of Broods: | Only one brood in a year |
The Eurasian Jackdaw is a bird known for laying blue eggs. They normally pair for life, and out of their mating are smooth and glossy pale blue eggs with brown markings.
Despite any reproductive failure, Eurasian Jackdaws commit to one partner only and don’t get into another pairing.
Due to their gregarious nature, expect Eurasian Jackdaws to fly as a colony while searching for the best nesting site they can defend from other species.
They nest in cavities, abandoned buildings, church steeples, or cliffs. The nest is made from hair, bark, soil, rags, and other materials.
Since blue bird eggs hatch asynchronously, the final hatchling often doesn’t survive. This is because both parent birds are more invested in caring for the older ones.
Looking after them takes 28 to 35 days. After they’re ready to fledge, the parents will continue to feed them for about four weeks before they leave the nest.
29. Goldfinch
| Incubation Period: | 12 – 14 days |
| Egg Size: | 0.5 inch (width) 0.6 – 0.7 inches (length) |
| Clutch Size: | 2 – 7 eggs |
| Number of Broods: | Up to two broods in a year |
A Goldfinch is a yellow and black bird that loves to dwell in gardens, and there’s a good chance you’d find one of its nests where bluish-white eggs are being incubated. These small but lovely birds can produce up to seven eggs in a brood.
Some of their eggs may also come in a grayish-violet color, with reddish spotting around it. The nest these eggs lay in is made from various and random materials like plant fibers, animal hair, and feathers.
Female Goldfinches put so much detail into constructing the nesting site, ensuring it’s sturdy enough to hold their eggs. About six days later, the whole nest is done, and the bird is ready to produce after mating.
When the reproduction is successful, Goldfinches may breed in the same location for the next year’s mating season. Other than that, they normally use a different nest.
30. Magpie
| Incubation Period: | 18 – 20 days |
| Egg Size: | 0.8 – 1.0 inches (width) 1.2 – 1.5 inches (length) |
| Clutch Size: | 1 – 9 eggs |
| Number of Broods: | Only one brood in a year |
The Magpie is another bird species that lays eggs in a bluish-green color with markings on the eggshell. The nests in which these eggs are laid are usually situated in secure bushes or trees a few meters above the ground.
Both adults do the nest construction and work on common materials, including twigs, rootlets, grass, and hair. This structure is held by a large, durable dome made from twigs with two entrances.
Unlike other birds that only take a few days to build their nests, Magpies take about 5 to 6 weeks. Once all the eggs are produced, the female will incubate them solely while the male feeds its partner.
When all bluish-green eggs hatch, the chicks are fed by both parents. By days 25 to 29, they will start to fledge. Further, a family of Magpies will stay close together until the autumn season starts.
31. House Sparrow
| Incubation Period: | 11 – 14 days |
| Egg Size: | 0.6 inch (width) 0.82 inch (length) |
| Clutch Size: | 4 – 5 eggs |
| Number of Broods: | Up to four broods in a year |
The House Sparrow is a pervasive brown bird known to lay oval eggs that can be light brown, greenish, or bluish-white. They’re mainly the year-round residents of North, Central, and South America.
These birds are aggressive and notorious for displacing other cavity-nesting birds. Although cavities are their preferred nesting sites, they can also be found breeding in pipes and other enclosures.
House Sparrow nests are generally made of coarse materials, like dry grass, twigs, paper, and string. Females then line it up with mammal hair, feathers, and other fine fibers.
Impressively, House Sparrows have a relatively long breeding period. They can be seen having their first eggs in early March and still have young chicks to care for in September.
However, if they reside in a place with a cold climate, the egg-laying season is short.
32. Eurasian Bullfinch
| Incubation Period: | 12 – 14 days |
| Egg Size: | 0.94 inch (width) 1.06 inches (length) |
| Clutch Size: | 4 – 6 eggs |
| Number of Broods: | Up to three broods in a year |
The Eurasian Bullfinch is a bird you’d usually see in woodlands, parks, gardens, and orchards, and these are the same places where you’d likely see its nest of pale blue eggs.
They live a sedentary life, but northern birds are seen migrating southwards in short or medium distances during winter.
Around May to July, breeding starts for birds of this species. After a successful courting, the Eurasian Bullfinch pair will start building the nest. Male Bullfinches are responsible for bringing the females twigs and rootlets.
They pick breeding areas, such as bushes, thickets, or tree branches, about 1 to 2 meters off the ground. Their nest is loosely structured and is made from moss, twigs, and lichens, lined with hair, roots, and moss.
Once all 4 to 6 eggs produced are hatched, the chicks are fed by both parents. They’ll start to fledge after 16 to 18 days.
33. Raven
| Incubation Period: | 18 – 21 days |
| Egg Size: | 1.2 – 1.4 inches (width) 1.7 – 2.0 inches (length) |
| Clutch Size: | 3 – 7 eggs |
| Number of Broods: | Only one brood in a year |
Despite the all-black plumage of the Raven, this bird species can produce eggs in olive, green, or blue with mottles of dark greenish, purple-brown, or olive markings.
They generally start breeding at ages 2 to 4. Ravens find their mates in autumn, and courting is done through acrobatic displays.
These monogamous birds then build a nest in preparation for the brooding season. They choose trees, cliffs, bridges, and even billboards for their nests.
While males bring the nest materials, females do most of the construction. The nest is made from branches and twigs and lined with wool, fur, grass, bark strips, and sometimes trash. This gets completed in nine days.
When an egg is hatched, both parents feed the young with food and water regurgitated in their throat pouch. The chick becomes ready to fledge in about 28 to 50 days.
34. Lesser Goldfinch
| Incubation Period: | 12 – 15 days |
| Egg Size: | 0.4 – 0.5 inches (width) 0.6 – 0.6 inches (length) |
| Clutch Size: | 3 – 6 eggs |
| Number of Broods: | Only one brood in a year |
The Lesser Goldfinch is also known to produce unmarked pale blue-white eggs. Their proportions are incredibly small, yet they stand out in the environment due to their unusual hue.
As sociable birds, Lesser Goldfinches can be seen in groups, flocking watering holes and feeding sites. When the breeding season starts, male Lessers establish their territories by singing from atop tall trees.
This is also their way of attracting their would-be mates. When female Lessers are wooed, their partners will start feeding them even during incubation.
Trees, bushes, willows, and cottonwoods are some places where they build their nests. For about 4 to 8 days, Females will work on the nest using leaves, catkins, bark, spiderwebs, and cocoons.
Once all the eggs hatch, the chicks stay in the nest for 12 to 14 days before they fledge.
35. Cassin’s Finch
| Incubation Period: | 12 – 14 days |
| Egg Size: | 0.5 – 0.6 inches (width) 0.7 – 0.9 inches (length) |
| Clutch Size: | 3 – 6 eggs |
| Number of Broods: | Up to two broods in a year |
A Cassin’s Finch lays light greenish-blue eggs with black, purple, and brown markings in well-built nests found in mature forests. They’re often seen 3,000 to 10,000 feet above sea level in their breeding season.
When female Cassin Finches look for a location to build their nest, their partners will chase away other males from the area. However, they become more tolerant of other pairs nearby when egg incubation starts.
All blue eggs are held by a nest made of twigs, lichens, coarse weed stems, and other materials. Meanwhile, the lining combines grass stems, plant fibers, shredded bark, rootlets, animal hair, and feathers.
About two weeks later, the chicks will start coming out of the greenish-blue eggs. They will be diligently fed by both parents. About 12 to 14 days later, parents and their young will start leaving the nest.
36. Cuckoo
| Incubation Period: | 10 – 13 days |
| Egg Size: | 0.5 – 0.6 inches (width) 0.6 – 0.8 inches (length) |
| Clutch Size: | 1 – 7 eggs |
| Number of Broods: | Only one brood in a year |
What’s fascinating about different Cuckoos is that they can lay eggs of different colors, such as blue, green, grey, and brown. This is believed to result from evolution due to brood parasitism initiated by Cuckoos.
To explain it further, Cuckoos don’t raise their own young. Rather, they lay their eggs in other birds’ nests. In response, host birds prevent getting tricked by ejecting eggs that don’t look like their own.
Hence, Cuckoos lay eggs identical to those of the host bird, typically Dunnocks. That explains why they can produce blue eggs with patterns when necessary.
Also, different Cuckoo species specialize in different host birds. That said, not all Cuckoos can lay blue eggs, and not all Cuckoos that can lay blue eggs can produce other colors.
37. Tricolored Blackbird
| Incubation Period: | 11 – 13 days |
| Egg Size: | 0.63 inch (width) 0.87 inch (length) |
| Clutch Size: | 1 – 6 eggs |
| Number of Broods: | Up to two broods in a year |
If ever you see a nest with pale blue eggs blotched with reddish brown hues and wavy lines, chances are that it belongs to a Tricolored Blackbird.
Their nests are even easier to find, especially since these are mostly built in freshwater marshes. Nowadays, some Tricolored Blackbirds may also consider places like triticale fields so long as they’re close to a water source.
A Tricolored Blackbird’s nest is built at least 8 feet above ground level with plenty of concealing vegetation. This is important since its blue-colored eggs can stand out in plain sight.
During nest building, female Tricolored Blackbirds do most of the work for three days with little help from males. Grasses and cattails are soaked in the water and weaved to form the sanctuary of their eggs.
A softer plant material is then used to line up the nest to help even more in incubating.
38. Clay-colored Thrush
| Incubation Period: | 12 – 13 days |
| Egg Size: | 0.55 inch (width) 0.62 inch (length) |
| Clutch Size: | 2 – 4 eggs |
| Number of Broods: | Up to two broods in a year |
A female Clay-Colored Thrush lays up to four pale blue eggs identified through its gray and red-brown markings. Between March and July, this bird can double-brood, so many nests near the ground floor are expected.
These nests are particularly found in open and semi-open habitats, such as woodlands and scattered groves of trees. Since they have been used to seeing humans, Clay-Colored Thrushes can also be seen in yards and parks.
When they start nesting, Clay-Colored Thrushes build a cup-shaped nest made of moss, leaves, rootlets, grasses, and other fine materials.
The nest is placed in a shrub or tree in the Clay-colored Thrush’s natural habitat. In urban areas, they opt for man-made structures. Only the female incubates all 2 to 4 eggs.
However, both sexes feed the young when they hatch. Signs of fledging can be observed around two weeks after a chick gets out of its eggshell.
39. Emu
| Incubation Period: | 46 – 56 days |
| Egg Size: | 3.5 inches (width) 5.1 inches (length) |
| Clutch Size: | 5 – 15 eggs |
| Number of Broods: | Only one brood in a year |
The flightless Australian bird called Emu is also a blue-egg-laying bird. Each egg comes in a unique shade, some in dark blue while others in jade green.
Before these eggs come about, Emus start selecting their pairs around December and January each year. Laying their eggs starts mid or late April; other hens will continue producing until October or November.
Naturally, Emu birds incubate their eggs by sitting on them. However, farmers opt for artificial incubation if these Emus are cared for on a farm. One reason for this is to achieve maximum production of Emu chicks.
Also, since Emu eggs are large, they will take 56 days to hatch. However, farmers check the eggs daily after day 50 to ensure all chicks are well.
40. Oriental Greenfinch
| Incubation Period: | 12 – 15 days |
| Egg Size: | 0.59 inch (width) 0.78 (length) |
| Clutch Size: | 4 – 5 eggs |
| Number of Broods: | Up to two broods in a year |
The Oriental Greenfinch ends the list by producing bluish-white eggs with white spots around them. These birds are found in woodlands and farmlands, displaying bold behavior as they share garden feeders with other birds.
Their nesting period is around mid-winter to mid-summer, and female Oriental Greenfinches are responsible for building their nests.
The cup-shaped nest is made from coconut fiber, grasses, and other soft materials. Their nests are constructed in the aviary at medium to high heights to ensure their eggs’ safety.
With two broods produced yearly, Oriental Goldfinches find it practical to reuse their nests. However, before producing the second batch, added materials are utilized to make the place more secure.
Meanwhile, only female birds incubate all blue eggs. Once all are hatched, they need at least two weeks before they can fledge. The chicks stay dependent for another 3 to 4 weeks before they leave the nest.
Why Do Some Birds Lay Blue Eggs?
Some birds lay blue eggs primarily for signaling, camouflage, protection, identification, and against UV rays. It may also be a passed-down characteristic with no particular adaptive value.
Below further explains each evolutionary reason why some birds lay blue eggs:
- Signaling: The color intensity of the blue eggshells can indicate the bird’s health status, although not always. With sexual selection coming into play, eggshell color may be one of the factors birds consider during previous breeding seasons in finding their pair. On the flip side, the presence of blue eggs helps other birds easily spot that a nest is already occupied.
- Camouflage: Natural selection has prompted birds to ensure they have heavily camouflaged eggs. That said, birds might be laying blue eggs for their species to thrive and survive. Blue eggs are difficult to spot by predators if the nest they lay on is near blue-green foliage. When these eggs are concealed, they have a higher chance of getting hatched.
- Protection from UV rays: Blue is more than just an eggshell coloration for some birds. For most, this hue acts as a protection for the embryo. It was explained that lighter-colored eggs don’t effectively fight off UV rays. If they’re too dark, the eggs may overheat. This could help explain why some birds nest on top, others low on the ground, and the rest, somewhere in the middle.
- Nest identification: Birds can recognize their own eggs through color, markings, and pattern. Since their eggs come in blue, it makes it easier for them to determine which nest they should land at. This uncommon color also hints that mother birds should not lay eggs in the wrong nest.
- Genetic trait: Laying blue eggs for other birds may be a genetic trait. To add further, only female birds can pass on the blue egg color. This suggests that no gene is required from the male bird to produce blue-hued eggs. This is the case for birds that lay blue eggs, and these findings need more research for eggs of other colors.
The reasons why there are blue bird eggs are not limited to the items listed above. Nonetheless, blue eggs produced by mother birds mainly increase their chances of reproduction by ensuring they survive incubation.
How Do the Colors Protect the Eggs From the Sun?
Colors protect bird eggs from the sun by limiting the heat the embryos inside are exposed to.
Since it’s established that ultraviolet rays can be detrimental to embryos, the intensity of eggshell colors plays a significant part in the survival of the bird’s chicks.
That said, a lighter egg cannot properly protect an embryo against ultraviolet radiation. However, if the color is too intense, much light is absorbed, resulting in the egg interior overheating.
On the other hand, moderate egg coloration effectively helps decrease light transmittance.
Where the nest is positioned, particularly considering its distance from the sun, also factors how effective the blue color-eggshells are in protecting the embryo.
Frequently Asked Questions
What Kind of Robin Lays Blue Eggs?
The American Robin bird is a member of the Thrush family that lays blue eggs. In North America, these birds are one of the most common songbirds you can come across with.
American Robins are all expected to lay blue eggs. In fact, Robin egg blues or eggshell blues were their first recorded color name in 1873.
What Bird Lays Blue Eggs on the Ground?
The most common bird species to lay blue eggs on the ground are the Bluethroats, Great Blue Herons, Emus, Great Tinamous, and Blue-Footed Boobies, to name a few.
This could be because the birds are flightless or find it better and more convenient to ward off predators on the ground. One technique some birds employ is by making a distress call.
If the predator approaches the nest, the bird will try to get its attention and fly off once the predator is distracted away from the nest. Overall, different birds have different strategies when it comes to protecting their nests.
What Bird Lays Small Blue Eggs?
The common birds that lay small blue eggs are Dunnocks, Blue-Grey Gnatcatchers, House Finches, Linnets, Eastern Bluebirds, and Blue Grosbeaks.
Bluethroats, Goldfinches, House Sparrows, Lesser Goldfinches, Cassin’s finches, Cuckoos, Tricolored Blackbirds, Clay-Colored thrushes, and Oriental Greenfinches are also included.
All these birds’ eggs are produced with lengths and widths of less than an inch.
What Bird Lays Blue Eggs With Brown Spots?
The answer to what birds lay blue eggs with brown spots are Blue Jays, Red-Winged Blackbirds, Dunnocks, Common Mynas, Blue-Gray Gnatcatchers, Varied Thrushes, Linnets, Blackbirds, and Blue Grosbeaks.
Adding to this list are the American Crows, Swainson’s Thrushes, Eurasian Jackdaws, Ravens, Cassin’s Finches, Tricolored Blackbirds, and Clay-Colored Thrushes.
These birds produce eggs of different sizes, shapes, and blue tones. Yet, they all bear light to dark brown spots or markings. Some may have just a few brown spots, while others may have them in greater intensity.
Final Thoughts
Blue bird eggs have continued to make humans wonder for a long time. Animal adaptation explains why birds lay eggs in this color, but more is yet to be known.
Since some, if not all, birds can be seen practically anywhere, there’s a good chance you’d find blue eggs in one of the nests around you. It’s best to leave the nest alone to allow successful reproduction.
Instead, you can study their behavior and observe them from a distance using binoculars.
Respecting their space and learning about their eggs and nest care habits are ways to show appreciation toward these blue egg-producing birds.
Now that you know what birds lay blue eggs, let us know which among them captured your interest the most by leaving a comment below!
