You're not alone if you've seen a small bird slightly bigger than a sparrow and didn't recognize it as a bluebird. Even on sunny days, perching bluebirds can appear to be a dull gray. But, if the sunlight hits one just right as it dives down to snatch an insect, you will suddenly see the iridescent blue of its feathers. In that moment, you just might find yourself saying, "Wow! So that's why they call it a bluebird."

There are three species of bluebirds in the United States and Canada: eastern, mountain and western. Eastern bluebirds are found primarily from the Atlantic coast to the Rocky Mountains, and their range extends from Canada though the United States to Honduras. The mountain bluebird is found in the Rocky Mountains and the western states, often at elevations of 7,000 feet and above. Its range overlaps with the western bluebird, which inhabits regions west of the Rockies from Canada to Mexico. Eastern and western male bluebirds have blue wings, backs and heads while the male mountain bluebird is blue all over. Females of each species are less colorful.

"Except for western bluebirds in New Mexico, most populations of bluebirds are considered stable and, in many cases, increasing in numbers," said Robyn Bailey, project leader for NestWatch, a Cornell Lab of Ornithology citizen-science program that tracks the nationwide status and trends in the reproductive biology of birds. The status of bluebird populations, at least as far as scientists have been able to measure them, wasn't always so bright.

The history of bluebird conservation efforts

A mountain bluebird perches on a nail Bluebird conservation efforts were slow to develop, but there are new tools for tracking populations. (Photo: Gary Hoard/FeederWatch)

Bluebird populations certainly decreased in from the 1940s to the 1960s, said Bailey, who offered several reasons for the drop off. Among those she ticked off were a lack of environmental safeguards that allowed the use of herbicides such as DDT; extensive logging wherein nothing was left behind, most particularly dead trees on the edge of forests where bluebirds could nest in tree cavities; and several severe winters in the East that prevented some populations of eastern bluebirds from feeding on berries, a favorite cold weather food source, knocking back this species in some areas.

However, Bailey is quick to add that it's impossible to know just how bad the declines were. "Just speaking broadly about all three species of bluebirds in North America, I would start by saying historically we have not had a great way to track bluebird populations or, really, any bird populations prior to the 1960s," Bailey said. "A lot of what was thought at the time to be dramatic decreases may not have been as steep as people perceived."

Regardless of the severity of declines in bluebird populations, numerous factors started turning in the bluebird’s favor in the '60s, Bailey pointed out. She said the most important of these were that science started to have some input about the fate of bluebirds and guidelines were initiated to save some trees for wildlife; federal agencies began stepping up environmental safety regulations; a nest box campaign got underway; and the bluebirds found an advocate in Lawrence Zeleny, a bluebird activist and prolific author from Beltsville, Maryland, who is credited with founding the North American Bluebird Society in 1978.

"Zeleny's efforts, which included writing the book 'The Bluebird: How You Can Help Its Fight for Survival,' really helped popularize the bluebird," said Bailey. "He's considered to be the person who inspired the whole nest box movement," Bailey said. "Bluebird nest boxes became really popular in the '60s and the thing for people to do. In most cases that dramatically increased local nesting bluebird populations."

Estimates of bluebird populations have been getting better since the '80s and '90s, according to Bailey. "Now we have better tools for measuring population change," she said. "We have breeding bird surveys, Christmas bird counts, NestWatch and eBird. These tools have given researchers a lot more data now than they have had historically, and so they are better able to track bluebird population trends than at any time previously.

"Currently, the data show that most populations generally are doing OK, except for the western bluebirds in New Mexico, where the trend has been declining. There are certainly areas where human development is taking habitat away from the bluebird, but there are other areas where bluebirds are increasing and the general trend is very stable for most locations."

Habitat is critical to attracting bluebirds

A mountain bluebird with a clump of dried grass in its beak This mountain bluebird is ready to build a new nest. (Photo: Mark Fuller/FeederWatch)

Homeowners can do a lot to help keep it that way. That’s because in many cases residential habitat can be good for bluebirds, said Bailey. It's important, though, that homeowners know which habitats will attract bluebirds and which ones are not suitable for them.

Importantly, these are not forest birds. All North American bluebirds prefer open or semi-open habitat, Bailey said. In the East, she said that's typically open grassland such as fields, meadows or pastures. In the Midwest, it's more prairie, and further west it's savannas or pinyon-juniper forests (open forest dominated by low, bushy, evergreen junipers and pines that are seen in Arizona and New Mexico). In the Southeast, there are some open longleaf pine forests. But, generally, they like open or semi-open area, such as residential areas, parks and school grounds.

Traffic signs, mail boxes and even utility lines along streets in residential neighborhoods that are not too heavily wooded are popular hangouts for bluebirds because they give them a vantage point from which to look down onto lawns for their next meal or for food to feed their young, said Bailey. But, said Bailey, even if you have a wooded and shady yard, you don't necessarily have to give up on attracting bluebirds. "If you have a shady yard, you may still be able to attract bluebirds if there are open areas around you. For example, if you live next to somebody with some open habitat, or there's a nearby golf course, assuming they are not spraying pesticides on the grass, or a community airport in your area you might be able to get them because they do nest in nature in tree cavities along forest edges."

How can homeowners attract bluebirds?

A western bluebird inspects a nestbox Nestboxes are a great way to bring bluebirds to your home, but you need the right box for your region's bluebird. (Photo: Jim Barnhart/NestWatch)

Assuming you have a bluebird-friendly habitat, perhaps the first rule in attracting them is don't apply pesticides to your lawn. Bluebirds are insect eaters, not seed eaters, and need a food base they can see and that is accessible. They will perform insect control for you for free.

Putting up a nest box is a great way to attract bluebirds. Plans for a nesting site can be found at NestWatch. "We have tips for how to place the nest box, what kind of habitat, how high, which direction it should face, and tips that might help you with competition from other species as well as the nest box plan," said Bailey. "So, if you did want to make one you could download the plan. These are free on our website."

A nice tool that’s also on the site, Bailey added, is helpful to people who don’t have an ideal bluebird habitat but who still want to put up a nest box. The tool is called Right Bird, Right House.

It provides a list of birds you can put out a nest box for in your geographic region and in your habitat type and provides plans for boxes for those species. "So, you can still put up a nest box and attract some beautiful birds to your garden. But it's good for you to know what's realistic for you in your area and your habitat. And we can help you do that."

If a bluebird box does work for you, be aware, though, that sometimes in residential areas there might be competition for those nest boxes. "Species like house sparrows, which are not native, like the same kind of nest boxes that bluebirds like," said Bailey. "Keeping an eye on the competition with house sparrows and managing the nest box is something that we talk about a lot on NestWatch," she said. "You shouldn’t just put out a nest box and never maintain it or check on it. You should be prepared to clean it annually and minimize competition from invasive species."

Something else to be aware of, she said, is that a lot of bluebirds don't migrate in winter. "It surprises people to see a bluebird in January, but it's really quite common as long as there is food. If there’s no food, they can migrate south in search of food, but if there is food they will stay. I have seen them in winter here in upstate New York where I live, and I have seen them in Michigan in piles of snow. They are fine with that as long as the food base is there."

That winter food base, she said, is fruit. To keep your bluebirds all winter, Bailey suggested planting trees and shrubs such as elderberry and serviceberry that bear desirable fruits. You can also put out food such as blueberries, peanut hearts, crumbled suet and mealworms (dried beetle larvae) that you can order online or find at stores that sell bird supplies and seed. If you want to offer them raisins or craisins, Bailey suggested soaking these in water first to soften them up. "The bluebird has a small bill, and it's not really a bill that's meant for crushing seed or tough, chewy fruit."

Just know, she said, that bluebirds are not typical feeder birds like titmice, blue jays or nuthatches. "They are not going to sit at a feeder and pick seeds out," she said. "But, if they learn to identify a feeder like a platform or a copper dish that has the proper food, they can definitely go to that feeder year-round. That can quickly get very expensive. One of the easiest and least expensive things to do is to provide the fruit in the form of landscaping."

Help the scientists help the birds

A mountain bluebird sits on a wire and a mountain bluebird flies out from a nest box Monitoring bluebirds is an easy effort with the right apps. (Photo: Mary Smiley/FeederWatch)

If you love watching and feeding birds, Bailey and her colleagues at NestWatch would like to hear from you. "Bluebirds are by far the top species people report to us," she said. "That being said you could report any chickadee or titmouse that you found that was nesting in your nest box or the robin that nests above your porch." They monitor all birds, she emphasized, adding that you can also report birds at your feeders, on neighborhood walks, or hikes in the mountains or around lakes or ponds. There are a couple ways to participate in these citizen-science projects through online websites and apps, including from NestWatch. They include:

Project FeederWatch is a bird feeder monitoring project that allows you to report birds you see at your feeder. The Cornell Lab of Ornithology has good data through this project that lets scientists know where bluebirds are showing up at feeders in winter.

eBird is a checklist project that allows you to use a smartphone to report birds from anywhere you might be birdwatching. Apps for reporting these data are available for Apple and Android devices. "This is essentially a checklist project," Bailey said."So, if you are a birdwatcher and you go on a bird walk, you can make a list of all the birds you see and report when you saw them, where you were, and how long you spent bird watching. These observations, will go into a database of bird sightings from all over the world."

By participating in these projects, you can help prevent possible future declines in bird species. And, perhaps, be better able to recognize a perching bluebird the next time you see one.