how to identify birds by their eggs

Bird eggs range in colors and can be ornately maculated with spots, blotches and scrawls. They vary in shape and size, and they must be thick enough to withstand the weight of an incubating parent but thin enough to allow the embryo to break through and hatch. Other than heat and protection, all the resources needed for a chick to grow and mature are packaged up cleanly and tightly in the eggshell surrounding it. Learn to identify bird eggs and discover how egg color, size and incubation change from species to species.

A kiwi lays the largest egg in relation to its body size, but hummingbirds come in a close second when you add up the total volume of their two eggs laid in each clutch. Nests are built and eggs are incubated by the females. Like all hummingbirds, this species lays immaculate white eggs, but the eggs sit so deep in the cup-shaped nest that predators don’t see them unless they stand directly above the nest. Learn everything you need to know about hummingbird nests.

What to Notice When You See a Wild Bird Egg

A few words of caution before we go on to features that can assist you in determining the owners of various bird eggs:

  • Never disturb an egg nest or a parent who is raising offspring. If a nest is being used by a native species, it is forbidden to disturb it. Furthermore, a worried parent might become so exhausted that they flee the nest, abandoning the chicks to perish.
  • Don’t assume an egg on the ground means it fell out of a nest. Certainly, search the area to see if you can find the nest it might have fallen out of, and then carefully replace it. However, some birds purposefully leave their egg scrapes on the ground. The markings on ground nest eggs will help them blend in with their surroundings.

Use a field guide to determine the type of bird egg most easily. I prefer ones with photographs rather than drawings. For me, theyre more realistic and show natural variations. However, if you don’t have access to such a resource, use these hints as a guide for confirmation.

It’s useful to measure an egg’s size by comparing it to another object. Ive seen several charts that use a U. S. dime as a point of comparison, most likely due to the large number of tiny eggs laid by wild backyard birds. An egg from a hummingbird, for instance, is about the size of a coffee bean, but an egg from a robin could be as big as a quarter.

Although we are all familiar with the shape of a chicken egg, wild bird eggs are not at all like those of chickens. And across species, they look different too. Is the shape of your egg more uniform, round, oval, or narrow and wide? Does it have a pointed end?

Cardinal Eggs / Shutterstock

The surface texture of eggs laid by backyard birds in the wild varies remarkably widely. While many of them are smooth, a similar number can feel pebbly or have tiny dimples all over them. Some wild backyard bird eggs have ridges and ripples. Eggs can also have a matte, dull finish or be glossy.

For fun, observe how the texture or finish of the paint resembles the glossy, matte, and eggshell textures of eggs the next time you go wall paint shopping.

The next feature, markings, along with color, are very helpful in identifying eggs. You should write down the general base color (beige, brown, white, etc.). ), whether the hue varies, whether the color is bold or subtle, and whether it is consistent throughout the entire egg.

Blue Jay egg / Shutterstock

Like color, the markings on an egg vary across species. Similarly, there are a variety of markings that can be discovered. It’s important to be able to differentiate between spots, speckles, and splotches for accurate identification. Assess their color and whether they are dispersed, concentrated, or maybe in a band at one end.

In addition to the egg, you can note additional hints that will aid in identifying it. You could record the nest’s appearance, location, materials, and number of eggs (keeping in mind not to disturb the nest or parents).

American Robin Bird Eggs Clutch size: 3 to 4 eggs

In North America, the pristine, vivid blue-green eggs in the mud-lined nest of the American robin are a reliable indicator that spring has arrived. Occasionally, they even emerge ahead of the season. When there are very few trees, robins may build their nests on the ground. Because robin clutches are easily plundered by a variety of predators, such as squirrels, snakes, and crows, many eggs fail to hatch. Adversity prompts robins to swiftly rebuild their nests, but subsequent clutches may have fewer eggs. Learn more about robin nests and eggs.

Blue Jay Eggs Clutch size: 2 to 7 eggs

Blue jays quickly remove sharp pieces of eggshell to keep their newly hatched brood safe. Additionally, discarding shells helps avoid microbial infestations and strong odors that could lead nest predators to the clutch location. In the family of this jay, only the female lays the eggs; however, both parents work to provide food for the hungry chicks when they hatch. Here’s what to do in the event that you come across a nest of eggs or a baby bird.


How do I identify a bird by its nest?

Noting what a nest is made out of can serve as a great identification tool. Nests can usually be made out of materials like mud, sticks, yarn, lichens, and grass. For example, eastern phoebes are a common bird that uses mud in their nest construction. House sparrows will use grasses, straw, and feathers.

How do you identify baby bird eggs?

Look at the size, shape, and color of the eggs, if present. The size of the eggs is related to the size of the parent, so small eggs will belong to small birds and large eggs to larger birds. Egg shape can also give important clues about the lifestyle of the layer.

Is there an app to identify bird eggs?

Whether you monitor an extensive nest box trail or find a single nest in your yard—track nests, eggs, and baby birds with the new NestWatch app. No data sheets necessary!

What bird lays tiny brown eggs?

Sandhill cranes lay relatively small eggs that are pale brown and marked with reddish brown blotches for camouflage. Both parents attend the nest and spend about a month taking turns incubating the eggs.