Blue Jay Eggs vs. Robin Eggs – Differences and Similarities

Can you tell the difference between a Blue Jay and an American Robin? If you can, congratulations! You have mastered Birdwatching 101.

But can you tell the difference between Blue Jay eggs and American Robin eggs?

If you were to find a nest full of eggs or find a broken eggshell (hopefully because the baby bird inside it has hatched), would you know to be on the lookout for Blue Jays nearby?

Or should you be listening closely to the melodious songs of the American robin?

Both of these birds are native to North America, and while they may look different, their eggs reveal some striking common features.

Robin eggs are blue. Bluejay eggs are blue, too. There are a lot of birds that lay blue eggs.

The long list includes Blue-Footed Boobies, Goldfinches, Starlings, Red-Winged Blackbirds, Snowy Egrets, Blue Finches, Dunnocks, and Titmice.

The eggs of American Robins and Blue Jays are the blue eggs you are most likely to find (unless you have blue egg-laying Araucana Chickens in your backyard).

In this article, we will tell you how to recognize American Robin eggs and Blue Jay eggs and tell them apart when you have a question.

How to Tell the Difference Between American Robin Eggs and Blue Jay Eggs?

Blue Jays are the most abundant bird in the United States. If you find a blue egg on the ground, there is a good chance it belongs to a Blue Jay.

Here are more ways to tell American Robin eggs and Blue Jay Eggs apart.


Blue Jay eggs are slightly larger than American Robin eggs, about 0.1 inches (2 or 3 mm).

This makes them slightly more likely to roll out of the nest but not roll very far.

If you find an egg underneath a nest, it is more likely to be a Blue Jay egg. If you find an egg rolled farther away from a nest, it is more likely to be an American Robin nest. In both cases, you should place the egg back into the nest.


Blue Jay eggs are blue and always have brown speckles. American Robin eggs are blue and never have brown speckles.

The blue of a Robin’s egg is brighter than the blue of a Blue Jay’s egg.

Blue Jay Eggs vs. Robin Eggs


Blue Jays build their nests quietly to avoid attracting attention to them. However, once they lay their eggs, they are very territorial.

They keep other birds and other animals (including humans) as far away as possible. American Robins are not as territorial.

To recap, when comparing Blue Jay and Robin eggs, keep these differences and similarities in mind:

Color of the eggBluish-greenBright blue
MarkingsHave brown colored spotsNo spots/markings
Size of the eggSlightly larger than Robin’s eggsSlightly smaller than Blue-Jays eggs
ShapeOval (similar to Robin’s eggs)Oval (similar to Blue-Jay’s eggs)
Clutch Size2-7 eggs3-4 eggs

All About American Robin Eggs

American Robins are one of the most abundant birds in North America.

They range year-round over almost all of the continental United States and the interior of Mexico.

They make their summer homes all over Canada and Alaska, except along the coast of the Arctic Ocean, and they like to spend their winters in South Texas, southern Arizona, and southern California.

Robins live in backyards, forests, parks, and bushes along busy city streets.

They fashion their nests from grass, hay, and mud in an open cup, placing them on sturdy branches, windowsills, eaves, ledges, and inside barns.

Almost everywhere in the Lower 48 states of the United States, their bulky nests and lighthearted songs are part of every year of outdoor life in the spring and summer.

You can recognize American Robins by their “red” breasts and brown backs. An adult American Robin will be 10 to 11 inches (25 to 28 cm) long. They are related to the thrushes.

American Robin

Robins are considered a species of least concern. They are not considered to be endangered.

Also read: Robin vs Cardinal – What the Difference?

Where You Will Find American Robin Eggs

You are most likely to find American Robin eggs in the spring.

Robins are more likely to nest in lower shrubs or trees, typically around 5 to 15 feet from the ground. They can also build nests on artificial structures like window sills, eaves, or outdoor light fixtures.

Robins use different materials for nest building, such as:

  • Grass and twigs
  • Mud and clay
  • Paper, string, and other man-made materials

You may come across broken robin-egg blue eggshells under a tree, on a sidewalk, or even in the street.

Like the babies of many other thrushes, baby Robins often leave the nest before they are ready to fly.

When you see eggshells, you will often see baby birds. The best thing to do is to leave them alone.

Or, if they are wandering out into heavy traffic or seem to be in danger from dogs or cats, place them on the ground beneath a bush so their parents can find them.

American Robins like to nest in the same place every year. Anyplace you find American Robin eggs this year, you are likely to find them next year.

Now, let’s get into the detailed description of American Robin eggs.

American Robin Egg’s Description

Robin eggs are known for their signature bright blue color, or “Robin’s egg blue,” and typically have no markings (as shown in the image below).

Robin Eggs

So if you find blue eggs with no spots, they are more likely to be of robin.

Their dimensions are 1-1/8 inch by 3/4 inch (28 by 21 mm).

Fun Fact: Cowbirds often peck Robin eggs and use Robin’s nest to lay their own. You may also see white eggs with dense, brown speckles with Robin eggs, which are laid by Cowbirds.

Clutch Size and Incubation Time

American Robins lay 3 or 4 eggs at a time. They take 10 to 14 days to hatch.

All About Blue Jay Eggs

Blue Jays live year-round across the lower 48 states east of the Rocky Mountains.

There are also Blue Jays in parts of Canada east of the Rockies that have less severe winter weather.

During the winter, there are Blue Jays in coastal Washington State and Oregon.

Blue Jays are an example of Bergmann’s rule. This rule states that in any species, individuals that live in colder climates will be larger than individuals that live in warmer climates.

Blue Jays in New England are about 30% larger than Blue Jays that live in Florida.

Everywhere Blue Jays live, they signal their emotional state by raising or lowering the crest of feathers on top of their heads.

When a Blue Jay is feeling aggressive or excited, its crest will be fully raised. When it feels threatened, its crest will look like a brush.

On Blue Jays that are feeding or flying with other birds, the crest will lie flat.

Like other birds with blue feathers, Blue Jays only look blue in full sunlight. Blue Jays look flue because of the way an interference pattern in their feathers reflects and refracts sunlight.

If the feather is crushed, it does not look blue anymore.

You can recognize Blue Jays by their blue feathers and prominent crests.

Blue Jay

At 10 to 12 inches (25 to 30 cm) long, they are slightly larger than American Robins. Blue Jays are related to crows.

Where You Will Find Blue Jay Eggs

Blue Jays live in many of the same paces as American Robins. They build their nests in forests, backyards, and hooded areas.

They will also make a home in shrubs and trees alongside busy streets. Their nests are open cups made from sticks, twigs, and mud, usually placed in trees.

They typically choose a spot where the tree branch meets the trunk, about 10 to 25 feet above the ground. Blue Jays are also known to use nesting boxes if placed in a suitable location.

Some common materials Blue Jays use for nest construction include:

  • Twigs and small branches
  • Moss and lichen
  • Grass and leaves
  • Mud and bark

You aren’t likely to find many broken Blue Jay eggshells. The parents consume the eggshells of their young shortly after they hatch to conceal them from predators.

They also consume the fecal sacs their chicks produce to keep the nest clean.

Now, let’s get into the detailed description of Blue Jay eggs.

Egg Description

Blue Jay eggs are light blue, covered with brown spots. Their dimensions are 1-1/8 inch by 3/4 inch (28 by 21 mm).

Blue Jay Eggs

Cowbirds often try to destroy Blue Jay eggs and use the Blue Jays’ nest as their own, but Blue Jays easily recognize the foreign eggs and throw them out of the nest.

Clutch Size and Incubation Time

Blue Jays lay from 2 to 7 eggs at a time.

They take 17 or 18 days to hatch.

What to Do When You Find a Nest with American Robin or Blue Jay Eggs Inside

When you find any bird’s nest, the best thing to do is to leave it alone.

The parents may be away feeding, bathing in a nearby stream, puddle, or birdbath, or finding materials to repair their nest.

The parent birds may be afraid to return to their nest if you spend too much time there.

They need to keep their eggs warm and in the right position for the chick inside to develop normally.

It is always best to observe bird nests from a distance. Let the young birds find their way into the world, and then you can enjoy watching them in flight.

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