Baby Bird Alert! This Surprising Kitchen Ingredient Will Encourage More Birds to Nest in Your Backyard

The heightened flurries of activity in the hedges and trees around my bird feeder are telling me one thing – for several feathered residents, the nesting season is underway. It’s hard to believe after a long winter huddled near the window, hoping to catch a glimpse of a passing chickadee in the frosty mists – but all of a sudden, almost in tandem with the unfurling of spring’s first blossoms, there’s a sudden rush to fill bird houses and nests, and there’s not a moment to lose!

For those of us who spend time hanging feeders and cleaning bird baths in the hope of attracting birds, this is an eagerly anticipated time. There is a profound sense of stewardship in watching a pair of northern cardinals or tufted titmice claim a corner of the yard as their own. As the morning air softens and the days stretch, it is a time of incredible industry for backyard nesters – and the stakes are high. While it’s vital to put out high-quality seed and fresh water, I’ve recently started adding something else to the bird table, something I was inspired to save from the compost heap.

So what’s this mystery kitchen ingredient, you ask? It’s none other than eggshells, and believe it or not, it’s one of the most direct ways you can help nesting birds raise a brood. Eggshells for birds may sound whimsical, but it’s surprisingly effective in giving birds the calcium-rich boost they need for nesting. Here’s how to use this everyday scrap to give the next generation of backyard songsters the best possible start.

Why Give Eggshells to Birds?

It might seem odd to give eggshells to birds that lay their own eggs, but there are good reasons to make this a regular habit. The main reason is that the birds will eat the shells, which are good for their health due to the presence of calcium. This is vital for egg-laying birds, supporting egg production and chick bone development.

In female birds, calcium in the diet helps them to form strong, properly shaped eggshells for their own offspring. Too little calcium can lead to brittle, thin eggshells or shells that don’t form properly or at all. Calcium is also important for non-reproductive functions, like bone strength and muscle function.

Just as we might take a supplement for bone health, female birds require a massive surge in calcium to produce eggs. A mother bird can lose a significant percentage of her body’s calcium stores in one day of egg-laying. If she can't find enough in the wild, her body may leach calcium from her own bones, leaving her weak and vulnerable. So leaving this off the menu would clearly be a feeding mistake.

In the wild, birds hunt for snail shells or small bits of limestone to satisfy the need for calcium. However, in many tidy or manicured garden environments, these natural sources can be scarce. By providing calcium supplements for birds in a safe way, you allow birds to spend less energy foraging and more time protecting the nest.

Male birds and non-nesting species benefit, too. Calcium aids in nerve function and ensures feathers stay strong and resilient for the long flights of spring. Species like purple martins, chickadees, bluebirds, wrens, blue-gray gnatcatchers, robins, and barn swallows actively seek out calcium bits. They often flock to a yard because a gardener has laid out a fresh shell snack. So putting out eggshells will encourage more birds to stick around in your yard for the long haul.

Shop Bird Nesting Prep

Make sure you have all the right bits and pieces to help your birds make the most of this egg-cellent kitchen treat. From crushing the shells to serving them up and helping with nesting materials, this trio of essentials helps your birdies nest easy, providing a nurturing backyard that will be irresistible to local songbirds.

Prepare Eggshells for Your Birds

While putting eggshells out can be useful and beneficial to your backyard birds, there are some risks if you don’t do it right. Dirty shells can transmit Salmonella infections to birds and other wildlife, which can be devastating. They can also attract predators. So you want to ensure your shells are as clean as a whistle before they hit the feeder. Also, always use shells from boiled or raw domestic chicken eggs. Avoid shells from wild birds, as this can interfere with natural disease cycles.

To clean the eggshells to eliminate any risk of pathogens infecting your birds, start by rinsing the empty shells to clean out any leftover egg white (albumin) or yolk. Then, you can either boil or bake the shells to disinfect them. If boiling, keep them in rolling, boiling water for 10-15 minutes to ensure they are clean. However, you might prefer baking, as it makes the shells more brittle and easier to crush.

For baking, set your oven to 250°F (120°C) and spread the rinsed shells on a baking sheet. Bake for 10-20 minutes. Hopefully, your shells will become slightly browned. Once they’ve cooled, it’s time to crush. You need the pieces to be small (about the size of a grain of rice, or smaller). Use your food processor or a solid pestle and mortar, like the Berard France Wooden Pestle and Mortar Set from Wayfair, to crush shells into grit-sized pieces that are easy for small birds like chickadees to swallow.

Dishing up crushed eggshells for birds, you also have a choice. It’s perfectly fine to mix up the eggshells with other bird feed, such as seeds, in your tube or hopper feeder. However, I like to use a shallow dish and serve up the shells separately – partly to track the amounts taken, and partly so birds can self-regulate their intake.

As with your feeder, offer eggshells in a place that provides shelter and safety, as part of a dedicated bird sanctuary. Birds won’t go for food that puts them at risk of predation. Spring is the most important time of year to offer supplemental calcium, but birds will appreciate it all year.

Other Sources of Calcium for Birds

While eggshells are the most accessible DIY option, they aren't the only way to fortify your backyard friends. If you aren't a big egg eater, or if you have a lot of birds to support (hello, purple martin landlords), then you may need to supplement. Crushed oyster shells, often sold at farm supply stores or pet shops, are a fantastic addition. You can buy Pecking Order Oyster Shells from Amazon. They provide a similar calcium-to-phosphorus ratio that is ideal for avian health.

Keep an eye out for suet cakes labeled as Calcium Fortified. Brands like Audubon Park often include calcium in their spring-specific blends to help mother birds during the peak laying weeks. You can buy Audubon Park Berry Suet Cakes from Amazon. Also, don't forget your natural garden pests. By maintaining a layer of leaf litter and avoiding harsh pesticides, you encourage a healthy population of snails and slugs. Many birds, like the wood thrush, will naturally forage for these snails to consume their shells for a quick calcium hit.

Ultimately, if you are feeding eggshells to birds, a multi-pronged approach is best. Use your recycled eggshells as the primary source, top up with supplemental options where necessary, and keep your yard messy enough that birds can find a few natural minerals in the soil and leaf mulch. This creates a resilient sanctuary that supports a range of birds – and they will naturally stick around where they are well fed and supported.

Extra Bird Care in Nesting Season

Providing food is just one part of the nesting equation. In April and May, birds are looking for the three S’s – Safety, Shelter, and Sustenance. To make your yard a five-star nesting destination, think about placement. If you are putting out eggshells or seed, ensure the feeders are located near evergreen shrubs or dense thickets, where little birds can nestle if a sparrow hawk suddenly appears.

Water is also non-negotiable. Nesting is thirsty work! A clean birdbath with a solar-powered bubbler, fountain or pump, such as the Bobigny Solar Powered Pump from Wayfair, prevents the water from becoming stagnant and attracts more species. Remember to change the water every couple of days to keep it fresh.

Finally, consider the soft side of nesting. Put out a few short lengths of undyed wool, twigs, hairbrush hair, or even dried mud in a shallow dish. You can buy Alpaca Fleece Nesting Material from Amazon for a snuggly boutique treat. Or try putting out a few white feathers near your eggshells. Birds like tree swallows love to line their nests with them and will play with them in the air before taking them to their dens.

Bird Feeding Favorites for Spring

Beyond your home-crushed eggshells, there are a few other staples every good bird feeder will need to be stocked up in during nesting season. Grab these tasty treats for a backyard bursting with activity – and to ensure the next generation stays close.

So there you have it. By simply pausing before you toss an eggshell, and offering it up to a passing beak, you are doing your bit to help birds to cope with the stresses of the season, and all in a simple, natural and inexpensive way. You might notice bird activity at your shell station peaks late afternoon and early evening, as songbirds stockpile calcium so they have a fresh supply for that first overnight egg.

Providing that extra boost of calcium is a gesture of kindness that will resonate through the entire avian community – and it will make your backyard a more desirable, safe, and happy place for the next generation. So make sure you pass on those surplus shells somewhere they will be truly appreciated this spring.

Need more ideas for timely gardening jobs and seasonal expert advice delivered straight to your inbox? Sign up for the free Gardening Know How Newsletter!