Attracting Birds
How to Attract Bluebirds
You cannot buy your way to bluebirds with a bag of seed. They want short open grass, a perch to hunt from, and a cavity to nest in, in that order.
The short answer
- Bluebirds eat insects and fruit, not seed. A sunflower feeder will never attract one, no matter how long it hangs.
- The strongest single attractant is a correctly built nest box on a predator-guarded pole in open ground, put up in late winter.
- The habitat requirement is short grass with scattered low perches. Dense woods, tall meadow and closely built suburbs mostly do not qualify.
- Mealworms work as a supplement and a training tool, not as a diet. A common guideline is roughly 15 mealworms per bird per day.
- Moving water is often the fastest thing that works, because bluebirds come to water in yards where they will not stop for anything else.
Bluebirds do not eat seed. Not black oil sunflower, not safflower, not mixes. If your plan for attracting the Eastern Bluebird (Sialia sialis) involves a seed feeder, that plan will fail for as long as you run it.
What bluebirds want is a hunting field and a hole. They perch low, drop onto insects in short grass, and nest in cavities they cannot excavate themselves. Give them open mowed or grazed ground, a few low perches, and a nest box built to the right dimensions, and you have made the only two changes that reliably work.
Mealworms, fruit and water are useful accelerants. They are not the foundation, and offering them in a yard with no open ground will produce nothing.
First, an honest habitat test#
Walk out and look at your yard as a bluebird would. Answer these:
- Is there at least a quarter acre of short grass or sparse ground, yours or a neighbor's, within sight of where you would put a box? Mowed lawn, pasture, orchard, cemetery, golf course edge and roadside all count.
- Are there low perches at 3 to 15 feet (1 to 4.5 m) around that open ground? Fence posts, wires, low branches, garden stakes. Bluebirds hunt by sitting and dropping.
- Is the ground free of broad-spectrum insecticide? A lawn treated for grubs and ants supports very few of the beetles, crickets and caterpillars bluebirds live on. See pesticides, lawns and birds.
If you answer no to the first question, your yard is not bluebird habitat and no equipment changes that. Wooded lots, dense shaded suburbs and tall unmown meadow all fail the test. The honest advice for those yards is to put your effort into chickadees, wrens and woodpeckers instead.
The habitat is the attractant
Bluebirds are one of the few backyard birds where the yard itself does most of the work. A mowed strip with a fence line beside it will out-perform a yard with three feeders and no open ground, every time.
The nest box, built to spec#
A nest box is the strongest bluebird attractant there is, and the dimensions are not negotiable. Boxes sold as decorative "bluebird houses" frequently have the wrong hole size, a perch, or no way to open them.
| Feature | Eastern Bluebird | Western and Mountain Bluebird |
|---|---|---|
| Entrance hole | 1 1/2 in (38 mm) round | 1 9/16 in (40 mm) round |
| Floor | 5 x 5 in (13 x 13 cm) | 5 x 5 in (13 x 13 cm) |
| Floor to hole | 6 to 8 in (15 to 20 cm) | 6 to 8 in (15 to 20 cm) |
| Mounting height | 4 to 6 ft (1.2 to 1.8 m) | 4 to 6 ft (1.2 to 1.8 m) |
| Perch below hole | None | None |
| Spacing between boxes | 100 yd (90 m) or more | 100 yd (90 m) or more |
Other essentials: untreated wood at least 3/4 inch (2 cm) thick, a roof that overhangs the hole by 2 to 4 inches (5 to 10 cm), drainage holes in the floor, ventilation gaps under the roof, a side or front that opens for cleaning, and shallow saw kerfs inside the front panel so chicks can climb to the hole. Nest boxes: sizing and siting has the full build detail.
Mount the box on a smooth metal pole with a baffle or stovepipe guard beneath it. A box nailed to a tree or a wooden fence post is a raccoon and snake feeding station.
Put boxes up in late winter, roughly February in the South and March in the North. If you have room for several, either space them 100 yards (90 m) apart or pair them 10 to 20 feet (3 to 6 m) apart, which lets a tree swallow pair take one and a bluebird pair take the other rather than the two species fighting over a single box.
House Sparrows will kill nesting bluebirds
This is the main reason bluebird boxes fail. House Sparrows are non-native, will occupy a box, and will kill adult bluebirds and destroy eggs inside it. Never let a House Sparrow nest go to completion in a bluebird box, and site boxes well away from buildings, barns and feeders where sparrows congregate. Tactics are in controlling House Sparrows at feeders.
Mealworms: a tool, not a diet#
Mealworms are what turn bluebirds that live near you into bluebirds that land where you can see them. They are not a food source the birds need.
Start with a shallow open dish placed in the open, near the nest box or near a perch they already use. Put out a small handful of live mealworms in the morning at the same time each day. Bluebirds learn a schedule quickly, often within a week or two, and will begin waiting before you arrive.
Once they are coming, move the dish to a caged or covered mealworm feeder if mockingbirds, robins, starlings or jays are cleaning it out. A cage with openings around 1 1/2 inches (38 mm) admits bluebirds and excludes most of the competition.
Quantity matters. A commonly cited guideline is around 15 mealworms per bird per day, offered in one or two sittings, which is enough to hold their attention without becoming a significant part of the diet. During nesting, offering a larger amount for a short window in the morning and evening is more useful than leaving a full dish out all day.
Dried mealworms work and store far better than live ones, but soak them in warm water for 15 to 30 minutes first. Dry ones are hard, unappealing and offer no moisture to nestlings. Mealworms for birds covers sourcing and storage.
What else bluebirds will take#
Beyond insects, bluebirds are fruit eaters, and that is what carries them through winter in the northern part of the range.
- Native fruiting plants. Sumac, dogwood, holly, eastern red cedar, serviceberry, viburnum, wild grape and Virginia creeper. Fruit that persists into January is worth more than any feeder. See native plants for birds.
- Chopped fruit. Blueberries, softened raisins, currants and small pieces of apple in an open dish. Fruit for birds has the safe list.
- Suet dough and crumbles. Bluebirds will take softened suet dough from a dish, though they rarely use hanging cake feeders. Suet: the complete guide explains the difference between raw suet and dough blends.
- Crushed eggshell or crushed oyster shell in a small dish during nesting season, offered the way described in grit, calcium and eggshells.
Water often works faster than food#
A bird bath with moving water is the single fastest way to get a bluebird into a yard that has never held one. Bluebirds are strongly drawn to the sound of dripping or splashing water and will drop into a bath from surprising heights.
Keep it shallow, 1 to 2 inches (2.5 to 5 cm) at the deepest, sited in the open rather than under shrubs, with a dripper, wiggler or small recirculating pump. Drippers, misters and moving water covers the options. In cold regions a heated bath in winter turns a passing flock into regulars.
Range and season#
Three bluebird species split North America. Eastern Bluebirds occupy the East, Midwest and southern Great Plains, and are resident in the South while northern breeders move south for winter. Western Bluebirds hold the Pacific states and much of the Southwest. Mountain Bluebirds occupy higher elevations and open country in the Rockies and Great Basin, moving to lower ground in winter.
If you live in a heavily forested region, a dense city, or a place where all three species are genuinely absent, no amount of mealworms will produce one. Check what is actually reported near you before investing in a nest box trail.
Winter is worth planning for either way. Bluebirds form loose flocks in winter, roost communally in cavities during cold snaps, and will use a nest box as a roost box. Leaving boxes up all year, cleaned out in fall, gives them shelter. Winter bird feeding covers the rest of a cold-season yard.
Clean the box between broods
Bluebirds often raise two or three broods a season. Removing the old nest within a few days of a brood fledging encourages the pair to renest in the same box and reduces the parasite load that builds up in used material.
What a first bluebird season looks like#
| Timing | Action | Realistic result |
|---|---|---|
| Late winter | Box up on baffled pole, open ground | Prospecting visits, or nothing yet |
| Early spring | Monitor weekly; evict House Sparrows | Pair claims box, nest building starts |
| Spring | Start a morning mealworm dish near the box | Birds learn the routine in one to two weeks |
| Late spring | First brood fledges; clean the box | Adults bring young to the dish |
| Summer | Second brood; keep water running | Peak activity, most reliable viewing |
| Fall and winter | Clean and leave the box up; fruit and water | Flocks, roosting use, occasional feeding |
A yard with good habitat can get a nesting pair in the first season. A marginal yard may take two or three years, and a yard with no open ground will not get there at all.
Common mistakes to avoid#
- Putting a seed feeder out and waiting. Bluebirds have no interest in it.
- Buying a decorative box with a perch, an oversized hole, or no way to open it.
- Mounting the box on a tree or wooden post with no predator guard.
- Siting the box next to the house or barn, which hands it to House Sparrows.
- Leaving mealworms out all day, which mostly feeds mockingbirds and starlings.
- Treating the lawn for grubs and insects, then wondering where the insect eaters went.
- Letting cats hunt the same open ground bluebirds forage on. See cats and birds.
Frequently asked questions#
What do I put in a bird feeder to attract bluebirds?
Mealworms, live or dried and rehydrated. Bluebirds do not eat seed, so a standard seed feeder is irrelevant to them. Beyond mealworms, they will take chopped fruit, softened raisins, blueberries and suet dough crumbles, usually from an open dish or a caged mealworm feeder rather than a hanging tube.
What size hole does a bluebird house need?
A 1 1/2 inch (38 mm) round hole for Eastern Bluebirds, and 1 9/16 inch (40 mm) for Western and Mountain Bluebirds, which are slightly larger. The hole must be exact. A larger opening lets in starlings, and a smaller one shuts the bluebirds out. The box should have no perch below the hole, because a perch mostly helps competitors.
How high should a bluebird house be mounted?
About 4 to 6 feet (1.2 to 1.8 m) above the ground on a smooth metal pole with a predator baffle beneath it. Mount it in open ground with the entrance facing away from prevailing weather and ideally toward a tree or shrub 25 to 100 feet (7 to 30 m) away, which gives fledglings somewhere to land on their first flight.
When should I put up a bluebird box?
Late winter is ideal, roughly February in the South and March farther north, so the box has weathered and been found before pairs start prospecting. A box put up in May can still be used for a second brood, since bluebirds often raise two and sometimes three broods in a season.
Why do I have bluebirds in winter but not summer?
Many bluebird populations are partially migratory or move locally in response to fruit supply, so winter flocks may be birds from farther north passing through or wandering. They may also nest nearby and simply hunt elsewhere in summer. A nest box is what converts winter visitors into a breeding pair.