With striking bluish-gray plumage, the sight of an eastern female bluebird is unforgettable. Male counterparts have deep blue and orange coloring.
The female bluebird appears gray from above and brownish on the underside. These birds have blue specks on the back with bright blue tails and wings.
This article is for avid birders who want to know the characteristics of the eastern bluebird. We cover everything from how these birds nest to their courtship rituals
1. Female Bluebirds are Monogamous
Female bluebirds will only mate with a partner once they pair up during the mating season and stay together until their partner dies. A male may have more than one partner, especially when the female has laid her last egg.
Amazingly, if the females don’t find a mate during the breeding season, they may choose to stay single all year round!
2. Males and Females Have Three Distinct Differences
The female eastern bluebirds are slightly larger, have dull gray plumage, and take primary care of their hatchlings.
Males are smaller and their key tasks are scavenging insects or worms, bringing food to the nests, and feeding the young ones. Male bluebirds don’t build nests or do broods, but aid in feeding the hatchlings and fending off predators.
3. Female Eastern Bluebirds Make Sharp Calls To Protect Their Territories
Whenever males go hunting for food, they leave the females tending the chicks and preparing the nests. When females spot danger, they make short but sharp calls to alert males to return to protect the nest.
If the males don’t arrive, the female bluebird may be forced to engage in a physical fight with other birds to protect their territory.
4. Female Bluebirds Choose Nesting Sites
During the breeding season, it’s the job of the females to find strategic nesting sites. Often, females will fight with other bluebirds over the best nesting places.
They are attracted to sites that provide three things: access to abundant food, protection from predators, and safety for hatchlings. When female bluebirds can’t find these requirements in one area, they move from one site to another as the weather changes.
5. Female Bluebirds Don’t Reuse Their Nests
Unlike larger birds such as eagles and hawks, the eastern bluebirds are small backyard birds that keep changing their nesting areas every breeding season.
However, some can choose to stay in one nest for more than one season, if the area is conducive all year round.
6. Female Bluebirds Prefer Old Pre-made Nests
Sometimes female eastern bluebirds build their own nests, but in most cases, they prefer old pre-made nests. They particularly like to make a home in woodpecker nests.
One reason females use old nests is that it’s easier to prepare and that these nests are already in a well-protected area. They’re cavity nesters and would definitely love your backyard nest box.
7. The Eastern Bluebird Lays Two Clutches Per Season
Females lay two clutches of eggs per season, where the first clutch is laid in April or May, immediately after the birds have moved south from their breeding grounds.
They usually lay the second clutch of eggs in late June or July. On rare occasions, some pairs can raise three or more broods in one season.
8. Bluebirds Lay Powder Blue Eggs
The color of the eastern bluebird eggs is powder blue, but these birds can sometimes lay white or pink eggs. Their eggs in the first breeding season are rich in color while those laid in the second season are paler.
It’s thought that the dry summer months contribute to pale coloration. The color of eggs makes it easy to identify bird nests and types.
9. Eastern Female Bluebirds Lay 4-5 Eggs Per Clutch
Female bluebirds usually lay between 4 and 6 eggs. However, younger birds can lay less while mature birds can lay more. Some birds can lay up to 8 eggs! These eggs are typically 1 inch long.
The female bluebird incubates the eggs for about 12-14 days, and then both the male and female help to feed the hatchlings. The young birds fledge or leave the nest, about 16-21 days after hatching.
10. Females Are More Hardworking Than Males
While both male and female bluebirds work together to feed and care for the young birds, until they’re fledged, females do more work. They use a lot of time caring for hatchlings, including incubating, brooding, and feeding them.
In addition, they repair the nests and ensure no other female birds lay their eggs on their nest. Scientific research posits that females spend 47.3% of their time working while males spend only 18.2% of their time taking care of the young birds.
11. Females May Lay Eggs in Nests of Other Bluebirds
Known in the ornithological world as nest parasitism, egg dumping occurs when female birds “dump” their eggs in the nests of other birds. Bluebirds exhibit this behavior and usually happen when a female is ready to lay eggs but can’t find other safe spots to nest and brood.
It also occurs when there’s plenty of food in one area. Sometimes, a female bluebird may lay eggs in the nest of another bluebird species, such as a tree swallow or a chickadee.
12. Unlike Most Thrushes, Female Bluebirds Have Unique Songs
Eastern bluebirds typically begin to sing and establish their territories in the early spring as they prepare to breed. These birds sing a moderately low-pitched, warbling song comprising 1-3 quick, short notes.
The complete song lasts about 2 seconds, and the females sing this song when they spot predators or competitive birds. The low-pitched “tu-a-wee” call is brief, lasting only about a second. Males usually make longer calls than females.
13. Eastern Bluebirds Wear the Same Plumage Throughout the Year
Most small birds change their plumage with the changing season. However, both male and female bluebirds maintain their color all year round. Bluebird pairs molt their plumage during the end of the summer and the fall seasons.
14. Female Eastern Bluebirds Living in Different Areas Can Have Color Variation
Female eastern bluebirds may indeed show some variation in their coloring depending on their location.
Those in Mexico and Central America and other southern regions have more reddish-brown coloring on their breasts, backs, and heads. Those in the northern regions like Canada and Alaska have bluish-gray coloring.
15. Eastern Bluebirds are Symbols of Love and Hope
Sightings of male and female bluebirds are signs of renewal, hope, and love. In most cultures across the world, these birds are signs of good omen. In North America, they symbolize the start of spring. After difficult times, a bluebird sighting can show a change of fortune.