The colors of eggshells are a mystery to many people. The most common color is white, but there are also brown eggs and even blue eggs! What’s the reason for this variation? Many factors can influence the coloring of an eggshell including diet, breed, light exposure, hormones and more.
The color of an eggshell is dependent on the bile pigment biliverdin. Biliverdin is found in all living organisms and is one of many porphyrins that are excreted from the liver into the intestines where it gets absorbed by food. Biliverdin is produced by liver cells as a waste product after breaking down red blood cells.
It has a blue color when mixed with air, which explains why some shells are greenish-blue or have no coloring at all. When there’s not enough biliverdin present, the eggs turn more greenish-blue, while higher levels will make them even more blue and less green.
Table of Contents
- 1 Red-winged Blackbird
- 2 Tricolored Blackbird
- 3 Blue-gray Gnatcatcher
- 4 Blue Grosbeak
- 5 Gray Catbird
- 6 Bluethroat
- 7 American Crow
- 8 American Goldfinch
- 9 Lesser Goldfinch
- 10 Cassin’s Finch
- 11 House Finch
- 12 Varied Thrush
- 13 Wood Thrush
- 14 Eurasian Bullfinch
- 15 Blue Jays
- 16 Starlings
- 17 Eastern Bluebirds
- 18 Western Bluebirds
- 19 Dunnock
- 20 Some More Birds That Lay Blue Eggs
- 21 Related Posts
The red-winged blackbird is a migratory bird that breeds across North America. It has been described as “a large, handsomely plumed bird with reddish shoulders and head, white throat, gray back and chestnut underparts.” The eggs are usually a light-colored bluish green, and covered with brown and/or sometimes black spots. The eggshells measure about 2.4 cm long by 1.6 cm wide on average for each egg in the clutch.
The Tricolored Blackbird is a medium-sized blackbird with some distinguishing features. It has the head, neck and chest of a grayish brown color and the back is also dark brown. The tail feathers are tipped in white or yellow and there is usually a streak of red on its wing tips. Tricolored Blackbirds live in southern Canada to Mexico City; they prefer to live near water sources such as lakes, rivers, marshes or mangrove swamps. The eggs are usually a light-colored bluish green, and covered with brown and/or sometimes black spots.
The Blue-gray Gnatcatcher is a common bird in North America. The most notable features of this species are its dark blue plumage and long tail, which has a white tip. This bird’s habitat includes many types of wooded areas with dense vegetation for nesting and feeding on insects as well as small spiders. They prefer open woods with shrubs or brushy areas near the ground where they can hunt for food on the ground. The nest of the blue-gray gnatcatcher has an average clutch size of 4 to 6 eggs, which are usually light blue with brown speckles on it. The parents incubate the eggs for 13 days and when they hatch, both parents feed their young and protect them from predators.
The Blue Grosbeak is a medium-sized songbird. It breeds in the eastern United States and Canada, its range extending from Nova Scotia to northern Georgia. The Blue Grosbeak is one of the most common breeding birds in North America with a population estimated at 2 million individuals. It also found in Central America and Northern South America. They are a medium-sized, black and white songbird with distinctive blue on their wings and tail. The Blue Grosbeak is a very rare bird and has a peculiar egg. It breeds in woodland edges, thickets or brush. The colors of the eggs range from blue to white, and can sometimes be speckled with some tiny brown spots.
The Gray Catbird is a member of the Mimidae family, which includes thrashers and mockingbirds. This species nests on or near the ground in brushy areas or hedges. They are found throughout North America, but only breed in southern Canada and the United States. Gray Catbirds lay 1 to 6 cyan (bluish green)colored eggs that will be incubated by the female only. Incubation last about 12 to 15 days. The catbirds are known for their characteristic songs which can be heard throughout most of the year but are especially noticeable during mating season. The male will use these loud calls to attract females for breeding purposes or to warn other males from entering his territory.
The Bluethroat is a small songbird found in Europe and Asia. The bluethroat can be seen during the springtime, breeding season, and fall migration. During the springtime, males sing from perches on low scrub thickets to attract females. The male then moves onto other patches of shrubs where he sings again to attract females for mating purposes. The eggs are usually blue or bluish green with thin reddish speckles all over it. They have clutch size of 5 to 7 eggs and incubate the eggs for 12 days.
The American Crow is a common and widespread bird in North America. It is found throughout the United States, southern Canada, Mexico, Central America and northern South America. The crow has been recorded as far north as the Arctic Circle in Alaska, to the Rocky Mountains of New Mexico. They are mainly found in urban areas but also inhabit rural farmlands. These birds are mainly omnivores, feeding on insects, small mammals, eggs of other birds as well as berries and fruit. Crows are also known to nest in colonies where they raise their young. Their eggs are bluish-green to dark yellowish-green color with small speckles of brown and grayish white, clutch size of 3 -9 eggs.
The American goldfinch is a small, seed-eating bird. It lays three to six bluish-white eggs usually covered with tiny brown spots, and incubation lasts 12–14 days. The average size of the egg is 13.5 millimeters by 11 millimeters. In addition, female goldfinches will lay two clutches in one season, typically around 18 days apart from each other. In general, the male takes care of nesting and egg sitting duties while the female spends time gathering food for her nestlings. The birds are considered monogamous because they mate for life; however this does not mean that males will not look elsewhere if his partner fails to provide enough food. Goldfinches are cavity nesters and use natural cavities or holes found in trees or human made nesting.
The Lesser Goldfinch is a migratory bird and has been known to migrate south for the winter. They are smaller than the American Goldfinch and are less likely to be seen near farms or other areas with humans. Lesser Goldfinches live in nests made of twigs, grasses, bark strips, feathers and sometimes mud that they build high up on trees. The Lesser Goldfinch typically lays 3-6 eggs that are light blue to light blue-green in color. Females incubate the eggs for about 12 days before hatching occurs.
The Cassin’s Finch, a small sparrow-sized bird, is found throughout North America. They live in coniferous forests and woodlands and eat seeds of various types. This bird was named after the ornithologist John Cassin who discovered it in 1854. Cassin’s Finches are able to fly away from predators if necessary but will also run up into trees when disturbed or threatened. The eggs of this species are pale greenish blue, speckled with brown, black, and slightly purple in color. Their egg length is 0.7-0.9 inches (1.8-2.4 cm) and their egg width is 0.5-0.6 inches (1.3-1.6) and have an incubation period of 12 days.
House Finches live in temperate climates throughout the world with their breeding range extending from central Alaska east across Canada south into Mexico and Central America; winters include southern US states and all of South America. House finches are found all over the world in many habitats, and they eat a variety of foods, but they mostly feed on seeds. They prefer nesting near ground level in protected places like cavities or crevices where their eggs will be safe from predators such as squirrels and snakes. This bird will lay one to six light blue eggs, usually tiny black speckles on them. The eggs will hatch within 12 to 16 days.
The Varied Thrush is a small songbird that resides in North America. It’s mostly found in the Eastern United States, but can also be found up to the Arctic Circle and into Central America. Varied Thrushes nest in trees or bushes during the breeding season, but they will use holes in buildings to lay their eggs during the winter months. The eggs of this bird are typically about 2 cm long with light blue coloring on top and brown speckles on the bottom. They usually lay between one and five eggs per clutch, but they can sometimes lay as many as eight eggs at once. The incubation period for 12 -14 days.
The Wood Thrush is a songbird that lives in Eastern North America. It can be found in open woodlands, clearings, or near streams and creeks. The Wood Thrush breeds in forests, orchards, and suburban habitats. The female usually lays 2-5 eggs which are blue/green with no speckles. The Wood Thrush is a small songbird that nests in the ground, usually under shrubs or trees. The Wood Thrush has a clutch of two to five eggs which are blue/green with no speckles, and incubates them for 12-14 days before they hatch into nestlings who stay in the nest for 12-14 days before they leave it.
The Eurasion Bullfinch is a small bird in the finch family. This species is native to Europe and Western Asia, but has been introduced to North America, where it was first recorded in 1847. They are usually found in woodlands and orchards, where they feed on insects and other invertebrates. The Eurasion Bullfinch has a orange-brown head and wings. It has a dark brown eye stripe, black throat, white belly, light gray breast and upperparts. The male bird sings sweetly to attract females for mating. The female lays 4 to 6 light-colored blue eggs, covered with tiny speckled russet colored spots, which she incubates alone for 12 days before they hatch.
In the Eastern part of North America, Blue Jays are usually found in areas that have a mixture of deciduous and coniferous trees. The population density varies by season; some populations move around during the winter while others remain stationary year-round. In the spring, many people enjoy watching and photographing the blue jays foraging in their yards. The birds are beautiful to look at and usually welcome a camera’s presence by posing with their head turned toward it. But what color eggs do they lay? There is not one set of answer as there are various colors of eggs that can be laid. The Blue Jays eggs colors can vary from greenish-blue tint, speckled with brown. Incubation is from 15 to 19 days.
The European starling is a small to medium-sized passerine bird that has the largest natural range in the world and has been introduced into many other parts of the world as well. These birds are often found near human habitations because they have adapted well to urban areas . These small to medium-sized passerine birds live around Europe and Asia, specifically England. The reason they’re named Starlings is because their eggs can be either blue or brown depending on the species. There are different types of Starlings like the European starling and white wagtail, which have been seen with blue eggs.
Eastern Bluebirds are small, insect-eating songbirds that often live in the eastern part of North America. These birds have a range from Canada to northern Mexico and parts of the Caribbean. They usually nest in low trees or shrubs near water sources. The female lays 3-5 eggs per clutch and can lay up to three clutches in a season. Their eggs are light blue to an almost whitish-blue color with brown speckles on them. The eggshells can be smooth or slightly rough with small bumps on them and usually measure about 3 inches long by 2 inches Nests are made up of twigs, grass, pine needles, and fur to keep it warm and dry for the young hatchlings.
Western bluebirds are a common sight in the U.S., as they can be found throughout most of North America. The Western bluebird is also known as the mountain bluebird, and their range extends from southern Canada to northern Mexico. Their eggs are light colored blue, bluish-white, or white with brown spots on them. They usually lay 2-8 eggs that are about 0.7-0.9 inches wide (1.8-2.4 cm). The incubation period lasts 12-17 days and they typically lay two eggs per day on average.
The Dunnock is a bird of timberland, yards and shrubs. This bird will build its nest in conifers or even bushes, laying 3-4 or 5 light blue colored eggs. The adult Dunnocks are grey with black head markings and red eyes. They have white underparts which show up clearly against the dark upper parts when they fly from tree to tree looking for food or intruders into their territory. It mainly feeds on insects such as caterpillars, beetles and aphids. It has an elegant shape and typically sings sweetly from trees all day long in late winter to early spring. The song can be described as resembling that of the nightingale, but more nasal with two repeated phrases and ending on a high note.
Some More Birds That Lay Blue Eggs
- American Robin
- Blue Mockingbird
- Snowy Egret
- Great Blue Heron
- Little Blue Heron
- Common Myna
- Snowy Egrets
- Lawrence’s Goldfinch
- Grey-capped Greenfinch
- Bicknell’s Thrush
- Clay-colored Thrush
- Dusky Thrush
- Swainson’s Thrush
- White-throated Thrush
- Bay-breasted Warbler
- Olive Warbler
- Eurasion Jackdaw
- Mountain Bluebirds