The Lark Bunting (Calamospiza melanocorys) is a medium-sized songbird found in the western half of North America. Its breeding range centers on the Great Plains of the United States and prairie regions of central Canada. Read on to learn more about where Lark Buntings make their homes.
Breeding Range
During the spring and summer breeding season, Lark Buntings can be found scattered across the Great Plains and prairie regions of North America. Their breeding range extends from southern Alberta and Saskatchewan south through Montana, Wyoming, Colorado, and New Mexico. It reaches east to western Minnesota, Iowa, Missouri, Arkansas, and Oklahoma. Smaller numbers breed in the eastern parts of Texas and Louisiana as well.
Within this broad region, Lark Buntings tend to favor shortgrass and mixed-grass prairies. They are most abundant in areas with scattered shrubs, like sagebrush or saltbush, interspersed in the prairie. They generally avoid dense or tall vegetation. Ideal breeding habitat provides open space for breeding displays, suitable nesting sites, and plenty of seeds and insects to feed on.
Key Breeding States
Some of the states where Lark Buntings are most abundant during breeding season include:
- Colorado
- Wyoming
- Montana
- New Mexico
- Oklahoma
- Texas
Colorado likely hosts the largest breeding population, particularly on the eastern plains. Breeding Bird Survey data indicates the species has experienced significant population declines in Colorado since the 1960s, though it remains common.
Wintering Range
Lark Buntings migrate south for the winter. Their winter range is centered in the desert regions of the southwestern United States and northwestern Mexico. Some key areas visited by wintering Lark Buntings include:
- Southern Arizona
- Southern New Mexico
- Southern California
- Southern Nevada
- Southern Utah
- Western Texas
- Northwestern Mexico
Within these regions, they tend to prefer areas of open desert scrub, agricultural fields, grasslands, and savannas. They mostly vacate their breeding range, though some may overwinter in southeastern Colorado, southwestern Kansas, and western Oklahoma.
Migration
Lark Buntings migrate through the Great Plains twice a year on their way between their breeding and wintering grounds. Key migration stopover spots include:
- Central and eastern Colorado
- Central Kansas
- Central Nebraska
- Western Oklahoma
- Northeastern New Mexico
Some isolated records of vagrant Lark Buntings have occurred outside the expected migration route across the eastern United States. But most follow this route through the Great Plains region.
Lark Buntings migrate during the day in large, mixed flocks with other songbirds like Horned Larks, Vesper Sparrows, and Chestnut-collared Longspurs. Males generally begin spring migration before females and arrive on the breeding grounds first. Fall migration starts in late August and runs through early November, peaking in September and October.
Year-Round Range
Lark Buntings are native to North America and spend the entire year on the continent. They breed primarily in the Great Plains and overwinter in southwestern deserts and grasslands of the United States and Mexico. Some general patterns in their year-round range include:
- Summer range centers on Montana, Wyoming, Colorado, and western Nebraska.
- Migration corridors connect through eastern Colorado and western Kansas.
- Winter range concentrates in Arizona, New Mexico, and Texas.
- Small numbers may overwinter within the breeding range.
The breeding grounds see the highest densities of Lark Buntings during the peak nesting season from May to July. The winter range builds up from November to March before birds head back north again. Migration routes see pulses of migrants in April-May and September-October.
Population Trends
Once considered one of the most abundant breeding birds on the Great Plains, Lark Bunting populations have declined significantly since the 1960s. The Breeding Bird Survey indicates a survey-wide population decrease of 2.7% per year from 1966 to 2015. Their numbers have dropped by over 75% in that time.
Causes for decline likely include habitat loss on the breeding grounds, climate change, pesticide use, and other factors. Conservation of remaining grassland habitat is important for stabilizing Lark Bunting populations. They are considered a Common Bird in Steep Decline by conservation groups like the National Audubon Society.
Habitat Preferences
Throughout the year, Lark Buntings prefer open habitats with sparse vegetation, including:
- Shortgrass prairie
- Mixed-grass prairie
- Shrub-steppe
- Sagebrush flats
- Desert scrub
- Agricultural fields
During the breeding season, they look for areas of prairie with scattered shrubs or small trees. Winter habitat is often more open desert or grassland. Habitat loss and degradation on the breeding grounds is likely a major reason for declining populations.
Range Map
Here is a map showing the breeding, wintering, and year-round range of the Lark Bunting:
Conclusion
In summary, Lark Buntings nest and breed primarily in the Great Plains states and provinces from southern Canada to northern Mexico. They migrate through the Great Plains to winter in the desert southwest and northwestern Mexico. Ongoing habitat loss in their preferred shortgrass and mixed grass prairies has caused significant population declines over the past decades. Conservation efforts aimed at preserving remaining prairie habitat will benefit Lark Buntings and other grassland-dependent species.