The blue grosbeak (Passerina caerulea) is a vibrantly blue-colored, finch-like bird. However, it is often identified first by its voice and not its color.
This bird commonly found in the southern United States in the summer often uses snakeskin in nest construction.
Males are the only ones that sing, and they put on an impressive display, showing their legs off to potential mates.
Females are a beautiful cinnamon-brown color and often have to tend to the parasitic eggs from cowbirds in their nests.
Read on below to learn about these fascinating blue grosbeak facts and more.
1. Only Male Blue Grosbeaks Sing
Females and males both produce a distinctive metallic “clink” sound for communication. However, males are the only ones that sing with a rich and melodic warble that rises and falls in pitch.
Males use songs to attract females and announce to other males that they have claimed a territory. Older males often sing longer songs as well.
This video shares the male grosbeak’s song with you:
2. They Flick Their Tails, Puff Their Chests, & Show Off Their Legs
Blue grosbeaks have a variety of interesting movements. They flick their tails and fan them out when perched.
To court a female, a male stretches his legs out and puffs out his chest. The female will look at and even peck the male’s feet to show her approval.
These birds also shift form from one leg to another when watching another bird eating. They may flap their beaks and open their bills to indicate that they want the food too.
3. Blue Grosbeaks Hop & Hover To Forage
Blue grosbeaks actively forage throughout the day, staying low to the ground. They awkwardly hop or hover low to the ground to search for food.
Blue grosbeaks also search for food in shrubs, trees, and low-tangled-like areas.
They eat primarily insects in the breeding season, but will also eat snails, spiders, fruits, seeds, and grains. Their hovering and flying abilities allow them to catch insects on the wing (hawking).
Before migrating, blue grosbeaks are seen foraging in small flocks, but at other times of the year, they forage with other bird species or their mate.
4. They Decapitate Insects For Their Offspring
Chicks need a high-quality diet to thrive and grow into strong adults. Insects provide the necessary nutrition for them.
Blue grosbeaks will prepare insects for their offspring’s meals. They tear off the hard-to-chew parts of insects such as the head, wings, and legs, and then offer the soft body to their babies.
5. Male & Female Grosbeaks Are Different Colors
Male grosbeaks are vibrant cobalt blue birds with large silver bills and black wing feathers.
They also have 2 chestnut-colored wing bars, with a wider bar of a darker shade on the upper portion and a lighter and narrower one on the lower portion.
Like other blue birds, the blue feathers are not from a pigment but reflected color as a result of the protein molecular structure of its feathers. The blue wavelength is not absorbed by the feathers and it is reflected back as what we see.
While females only have hints of blue on the back and rump, they present with a beautiful cinnamon color and some black wing feathers.
Their color is more intense on the head and fades in the underparts. She has 2 chestnut-colored wing bars like the male.
Juveniles appear in the same coloring as females, regardless of sex.
6. They Have Huge Metallic-Colored Triangular Bills
This bird is named after its huge conical beak which is a large part of its face. In French, the adjective “gros” means thick.
The male blue grosbeak has a large silver-toned triangular bill. The female’s bill is also bulky and triangular but appears to have a more golden tone.
7. Blue Grosbeaks Are Confused With Other Blue Birds
Due to the male’s vibrant color, they are often confused with other birds such as the bluebird, blue jay, indigo bunting, and lazuli bunting.
The lazuli bunting in particular has black and orange-like markings and a silver bill that closely resembles the blue grosbeak’s bill.
Although a quick comparison shows their blues are different blue-toned hues. Lazuli bunting has a lapis-gemstone coloring and blue grosbeaks are a deep cobalt blue.
8. They Are Serially Monogamous
Blue grosbeaks are serially monogamous, meaning that they pair up for breeding seasons.
The breeding season runs from April to August but often takes place later than other breeding birds. They raise 1 or 2 birds with 3 to 5 eggs each time.
After the breeding season is over, they join small flocks to feed before migrating. In the next breeding season, they pair up with a new mate.
9. Grosbeaks Nest In Low, Shrubby Spots
The female does the majority of the work for nesting. She builds a compact, cup-shaped nest in low places, near open areas.
Nests can be found low in trees, shrubs, thickets, tangled vines, overgrown fields, and bushy areas. They are typically built 3 to 10 feet above the ground.
10. They Use Snake Skin & Other Materials To Build Nests
Blue grosbeaks often use snake skin in their nests. The snakeskin is either displayed in pieces or coiled around the exterior of the nest. This is to help scare off potential predators to protect their eggs and hatchlings.
The cup-shaped nest is primarily made of twigs, weeds, pieces of bark, leaves, and other man-made materials such as paper or string. It is then lined with rootlets, animal hair, and fine grasses.
11. Males Feed The First Brood When A Second One Is On The Way
Hatchlings are fed primarily by the female for 10 to 12 days until they fledge the nest.
The female will begin building her second nest, and the male will continue to provide food for the first brood fledglings.
12. Blue Grosbeaks Can Live Over 10 Years Old
On average, blue grosbeaks have a lifespan of 6 to 7 years in the wild. However, the oldest recorded blue grosbeak was over 10 years old, as discovered through a banding project.
This means that if you spot a blue grosbeak near your home feeding year to year, it just might be the same one.
13. Some Blue Grosbeaks Stray From Migratory Paths
Blue grosbeaks often migrate to breeding locations later than other birds, absent in early summer.
They are found in shrubby habitats across North America during the breeding seasons, and then spend winters in Mexico and Central America.
Populations that breed in Central America do not migrate.
Blue grosbeaks traveling from the east are thought to migrate across the Gulf Of Mexico, and those located west travel over southern land.
However, stray blue grosbeaks will appear north of their breeding range taking a longer path before heading south.
14. They Can Be Difficult To Locate
Blue grosbeaks are a shy species that often dart into shrubbery if a threat is nearby. So, they can be hard to spot despite their brilliant coloring.
Often, blue grosbeaks are identified by their sounds first.
To locate them, listen for the male’s warbling or their distinctive metallic “clink”. Then scan the tops of shrubs, small trees, and thickets where the sound is coming from.
15. Cowbirds Parasitically Use Grosbeaks’ Nests
While blue grosbeaks face threats from predators such as cats and raptors, they are also parasitized by the cowbird.
Cowbirds lay their eggs in other birds’ nests to be incubated and raised by other species of birds. The cowbird hatchlings are often larger and need more food and attention.
This results in the biological birds receiving less attention and potentially failing to thrive.
Male blue grosbeaks are a beautiful cobalt blue and their female counterparts are a lovely shade of cinnamon-brown.
These fascinating birds nest amongst show shrubbery and thickets. They are found in open areas, feeding and foraging along the ground. They break down insects by removing their heads, legs, and wings when feeding them to their hatchlings.
Despite their brilliant coloring, blue grosbeaks are hard to find amongst the shrubbery. They are typically located by the male singing or their distinctive metallic “clink” sound.
Males put on an impressive show for potential mates by stretching out their legs, puffing up their chests, and singing songs. Once mates are matched, they stay together for the season, raising 2 broods of offspring.