The official state bird of Colorado is the Lark Bunting (Calamospiza melanocorys), a distinctive songbird representing the state’s vast prairie landscapes. This species is native to the shortgrass prairies of eastern Colorado, an environment often overshadowed by the more famous mountain regions. The Lark Bunting is a New World sparrow species known for its strong presence in the state during the warmer months.
The History of Its Selection
The movement to designate a state bird for Colorado gained momentum in the late 1920s as other states adopted avian symbols. Roy Langdon, a Fort Collins educator and president of the Colorado Audubon Society, became a fervent advocate for the Lark Bunting. He argued that the state’s official symbols neglected the significant prairie ecosystems and agricultural interests of eastern Colorado, focusing too much on mountain flora and fauna.
Langdon published extensive materials, including a pamphlet titled “Seventeen Reasons WHY THE LARK BUNTING Should Be Colorado’s State Bird,” to sway opinion. The campaign emphasized the bird’s native status and abundance across the plains, making it a fitting representative for the entire state. The Lark Bunting was officially adopted by the Colorado State Legislature on April 29, 1931, through Senate Bill No. 251, securing its place as a unique symbol for the Centennial State.
Distinctive Physical Characteristics
The Lark Bunting is a medium-sized songbird, typically measuring between 5.5 and 7.5 inches in length. It has a stocky build and a heavy, conical, blue-gray bill. The species is notable for its marked sexual dimorphism and dramatic seasonal plumage changes, which affect male identification throughout the year.
During the breeding season, the male is striking, displaying a velvety jet-black body with a conspicuous, large white patch on its upper wing. This bold black-and-white pattern is central to its visual identification. Females and non-breeding males present a much more subdued appearance, featuring streaky brown and grayish plumage that provides excellent camouflage in the grassland environment.
The white wing patch is still present on non-breeding birds, but it is duller and less extensive, though visible in flight. Males perform an impressive flight song display during courtship, ascending rapidly 20 to 30 feet into the air. They then float down on outstretched wings while singing a complex melody, which is a mix of musical whistles, trills, and buzzy notes, often delivered from a high perch or during the aerial performance.
Ecology and Seasonal Range
The Lark Bunting is a summer resident in Colorado, inhabiting the shortgrass prairies and open grasslands of the eastern plains. Its preferred habitat includes native vegetation dominated by blue grama grass and wheatgrass. The birds typically arrive in April, with males establishing territories before the females arrive.
This migratory species spends its breeding season across the central Canadian and mid-western United States prairies. Fall migration begins early, sometimes in late July, as large flocks move toward wintering grounds in the southern United States and northern Mexico. Although primarily found on the plains, migrating flocks are sometimes observed at elevations up to 8,000 feet.
The Lark Bunting is primarily a ground forager, with its diet shifting seasonally. During the summer breeding season, the diet consists predominantly of insects like grasshoppers, beetles, and caterpillars, which are essential for feeding their young. Outside of summer, the diet transitions to a higher proportion of seeds from various grasses and weeds.
Nesting occurs on the ground, often in a small depression sunken into the soil. The nest is an open cup made of grass and rootlets, usually situated next to a plant or grass clump for shade and cover. This ground-nesting behavior is an adaptation to the open, low-vegetation environment of the prairie.