Identifying House Sparrow Eggs

Bird watchers love to watch house sparrows that visit their backyard, or they might go searching for them in local nature spots. The chances are, however, that you’ll be able to spot one out of your backyard with no issue since they are one of the most common backyard birds in the country.

They are common in both urban and suburban locations and generally prefer habitats that are close to humans, hence why they might take up residence outside of your window. You might even find nests in outdoor lighting fixtures, kitchen vents, rooftops, gutters, or crevices near your home.

Identifying an egg, however, can be slightly tricky and every eager bird watcher will want to know how to do it. They might want to be able to control the environment of the bird or watch a new one hatch and begin life.

They are interesting creatures and their nests and eggs can be just as interesting. This is why we have written this article, to give you all the information you may need when trying to identify a house sparrow egg.

How Can You Identify A House Sparrow Egg?

For a beginner bird watcher or someone who isn’t too familiar with bird eggs, spotting a house sparrow egg can be difficult, however, a more experienced bird enthusiast will tell you it’s quite simple. They are around 22.5 x 15.5 mm in size and look relatively glossy with a whitish edge.

They usually have heavy brown or blue-gray spots and the mothers usually lay around 3-6 eggs at one time. When a house sparrow lays an egg from a higher altitude, it may not lay as many eggs. A clutch size will depend on the conditions of the season and the age of the female, as well as breeding density.

Size Difference

House sparrow eggs offer differ in size dramatically. The sparrows that hatch from much bigger eggs are bigger birds than the smaller ones which come as no shock to the average bird watcher.

It is been a topic that has been researched in the bird community and experts say that the difference from the smallest egg to the largest egg in volume can vary up to 50 percent.


When it comes to survival rates, the larger eggs are good for the short-term survival of young babies as during wetter months, parent house sparrows need to venture out in search of food. Nestlings need to have much more energy reserves from a larger egg to survive on their own when their parents are out hunting for their dinner.

The same experts also discovered that young that hatched from smaller-sized eggs survive better in warmer temperatures than those hatching from larger eggs. At higher temperatures, the same reserves help long-term survival from all-around faster growth.

It’s also possible for young to grow too fast. This can occur when an egg has a high level of reserves mixed with too much food and temperatures that are too high and this can lead to a lower survival rate. Oxidative stress is usually the cause of this and the bird’s speedy growth increases its reactive oxygen species.

When a bird or any other animal grows too fast, the body’s defense against compounds struggles to keep up and this can lead to shorter telomeres. Telomeres are the caps at the tip of a DNA strand and they help prevent genes from being damaged as the cells divide.

The length of life and the length of a telomere have been connected by biologists in the field.

House sparrows cannot predict the weather conditions of the season to make sure their batch of babies is the best fit for survival. However, they solve this problem themselves by laying a range of different-sized eggs that belong in the same clutch. This increases the chance that some eggs will hatch properly and survive.

Mating Habits

Mating habits are what start off the whole process. The egg and nest of all house sparrows begin with this. Courtship often happens between January and July and during this time, male house sparrows will claim their nesting site, fighting any other bird that attempts to step on their territory. This makes them very territorial and protective birds.

The male then begins chirping in an attempt to attract female house sparrows and as they get close to the nest, the volume of the chirping increases. Often, other males will join in and they will chirp together, often trying to win the attention of the same female house sparrow. When they pair up, the mating ritual starts.

Nesting And The Young

House sparrows often stick around all year and close to home. They do not migrate like many other backyard birds and they may recycle the same nest, using it multiple years in a row.

A study shows that most house sparrows remain within a radius of 1.25 miles in the nesting period and refuse to fly any further than 5 miles outside of their original nesting site. That means, if you spot a nest in your backyard, they are often there to stay.

They use these nests all year long and during the springtime and summer months, they will raise their young there. They sometimes raise four broods per season, all in one nest. During the fall and in winter, the nest is a place of rest and roosting during the night.

They can be found up trees, in buildings, in birdhouses, and crevices near the backyards of humans. However, these birds can multiply quite quickly and nest all through the year so they can become an issue for some homeowners.

The female starts to lay her eggs after the nest is built and will usually lay up to around 4 eggs at once. The female incubates the eggs for around 12 days and after her young hatch into the world, it’s only a brief visit as they leave around 17 days later. Baby house sparrows take those 17 days to fledge. The parents will still look after them as they cannot feed themselves.

The male sparrow often takes charge of the young and the female behind to lay her next clutch of babies.

As we mentioned, these birds move fast and multiply at rapid speeds. After one set of babies has been hatched, think about how the mother is ready to do it all again after just a few days!

Identifying A Nest

So what does a nest look like? Simply put, a circle. It is a perfect sphere and is around 8-10 inches in diameter. Their nests are also made with materials such as debris, trash, straws, leaves, grass, twigs, and paper. The inside of the nest is lined with grass or sometimes feathers and it is usually a bit of a mess.

Feeding Habits

Like a lot of birds, house sparrows are not fussy when it comes to what they like to eat. They like a variety of seeds, as well as oats, wheat, and corn. They like to forage around outside on the ground and fly into your feeder in your backyard for some suet.

They also enjoy eating spiders and other small insects. If you leave spare food around on the ground, especially in your backyard, they’ll come and scrape those up with a blink of an eye. They are known as the trash disposal of the bird world. 


House sparrows are known to be quite aggressive birds. You’ll often find them fighting with tree swallows, martins, and other small birds such as bluebirds.

These species we have just listed face losing control of their nests due to house sparrow bullies and this can cause issues for bird watches attempting to put a purple martin house out or attract bluebirds to their backyard with a bluebird box. A house sparrow might bully their way in by angrily pushing the other birds.

The house sparrow aggression is purely down to personality. Some birds are just friendlier than others. House sparrows were imported from England in the opes and would control the population of caterpillars by harming the shade trees.

The imported birds spread throughout the US, as well as up towards Canada where they stopped attacking caterpillars. Instead, they went after other birds. Native birds do not have the evolutionary changes and advances to keep up with the aggression that house sparrows have and as a result, they are labeled bullies to other species. 

On the other hand, they aren’t the biggest bully in the yard. Kestrels, coopers, and sharp-shinned hawks are not their friends either and owls or shrikes often try to attack them too.

Moreover, cats and dogs are not the friendliest animals towards house sparrows and will attempt to eat their young, their eggs, or even grown adult house sparrows in one. 

Controlling The Large Numbers Of House Sparrows

The house sparrow is one of only two birds that is not native or protected by Federal Law in the US. This means it does not go by the same rules as most other backyard birds. There are no laws governing this bird, just as there aren’t any laws governing house sparrows.

The birds were introduced by other continents and are predators that are, as we have mentioned, very aggressive to other native birds. They are so rough, that they may even kill other birds to protect their nest.

It’s not simple to attempt to get rid of a house sparrow after it has taken up residence in your backyard. They often come in large numbers and their activities of terrorizing other birds may be quite overwhelming. However, there are a few methods that might help you out.

Cracked Corn

Cracked corn may be the way of getting rid of those aggressive backyard birds.

One of the biggest issues with house sparrows is that they love to dominate your backyard feeder. This means if you leave a large amount of cracked corn around 15 feet away from your feeder, or outside your backyard, they might opt to go for this instead.

They enjoy cracked corn more than any other food and as it is one of the cheapest food you can buy in the store, it’s also a budget-friendly way of attempting to reduce house sparrow numbers and stop them from dominating your feeder. 

Nesting Site Monitoring

Like we discussed earlier in the article, house sparrows enjoy nesting and living out their life near other humans. They like to collect trash to build their nests and eat food people leave lying around by accident.

One method you can also try is to eliminate and monitor places in your backyard and around your home where they might choose as a nesting site.

If you see a house sparrow making a nest, remove this as soon as you possibly can. We know this seems harsh, but you’re protecting the native birds as well as preventing a huge population of house sparrows from taking up permanent residence outside your back window.

You can even attempt to install netting around the crevices of your home to stop them from making a nest inside the house.

Final Thoughts

We know that although some bird watchers are keen to spot them and their nests, house sparrows are not everyone’s favorite backyard birds and we know as they are so common across the country, it won’t be long till you spot a nest outside your backyard.

Though when hatched, these birds can be annoying, aggressive, and dominating, it’s important to remember that at the end of the day, they are just attempting to survive like many other birds out there that we all know and love.

House sparrows are here for the long run and if you start to accept them, you can even learn to love them. After all, once hatched, baby house sparrows can be quite cute. Appreciate them as one of God’s creatures and laugh at the entertainment they might bring to your morning cup of coffee during the spring.