This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the lark bunting.
Deemed the state bird of Colorado in 1931 for its unique aerial song and display, the lark bunting is a common bird throughout central North America, a widespread native in western prairie, sagebrush steppe and desert grasslands. This medium-sized member of the sparrow family moves in loose colonies up from wintering grounds in Mexico and southern Texas, Arizona and New Mexico. Upon arrival, they split into smaller groups where males oftentimes maintain territories with multiple mates in breeding sites with tall grasses and shrubs to hide their cup-like ground nests. Males typically establish their territory and then spend weeks performing courtship stunts, flying 15 feet off the ground only to sing elaborately on their descents to attract mates.
Upon entering breeding season, adult male birds transform from brown streaky sparrow-like “basic” plumage into their bold black and white “alternate” plumage. They are predominantly black, but have striking large white patches on their wings and white tipping on their tail feathers. Females and immature males appear a much streakier brown. Both males and females have a distinctly conical bluish gray bill built for an insect and seed diet.
Though much of their habitat is protected by generations-old family ranches, lark buntings are considered as a “common bird under steep decline” by Cornell Lab of Ornithology, and Partners in Flight estimates that numbers may have fallen by as much as 86 percent since 1970. Habitat loss from residential and energy development in the grassland ecosystem is the main culprit to account for this loss. Restoring lands previously disturbed to native grasses has proven effective to encourage this species’ return.
Though predominantly known to inhabit lower elevations, lark buntings have been recorded passing through this corner of the Rockies in migration. A trip down to Navajo Lake or points south dominated by sagebrush at this time of year may afford folks a socially distant glimpse of our state bird.
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