The Dickcissel (Spiza americana) is a sparrow-sized songbird found primarily in the grasslands and agricultural fields of central North America. It is a medium-sized bird with a grey face, yellow breast, and distinctive black “bib” on its throat. The Dickcissel breeding range spans across the Great Plains and Midwest, from Texas up through the Dakotas, with highest densities in Nebraska, Kansas, Oklahoma, and eastern Colorado. During winter, most Dickcissels migrate south to Mexico, Central America, and northern South America. Determining the full range of this migratory songbird provides important information about its habitat needs and conservation status.
What is the Dickcissel’s breeding range?
The core breeding range of the Dickcissel centers on the Great Plains of the central United States. According to the Cornell Lab of Ornithology, the breeding range extends from southeastern Wyoming and western Missouri east to Ohio and Kentucky, and from southern Texas north to central North Dakota and Minnesota. The highest densities are found in Oklahoma, Kansas, eastern Colorado, Nebraska and the Dakotas.
Within its breeding range, the Dickcissel frequents grasslands, hayfields, meadows, weedy fields, and other open habitats with dense, seed- and insect-rich vegetation. It is frequently associated with agricultural lands. The conversion of prairie to cropland initially benefited Dickcissel populations by creating ideal breeding habitat. However, more intensive agricultural practices and clean farming methods have caused populations to decline across much of its range since the 1960s.
State | Breeding Density |
---|---|
Texas | Common |
Oklahoma | Abundant |
Kansas | Abundant |
Nebraska | Abundant |
South Dakota | Common |
North Dakota | Uncommon |
Minnesota | Uncommon |
Western Range Limit
The western edge of the Dickcissel’s breeding range centers on the arid shortgrass prairie region of the Great Plains. In Texas, Dickcissels breed west to the eastern Panhandle. They are scarce to absent in the arid landscapes west of the 100th meridian. The range extends slightly farther west in Oklahoma, with breeding confirmed west to the eastern side of the Panhandle.
In Kansas, breeding distribution covers the eastern two-thirds of the state, becoming more scattered west of central Kansas near the 100th meridian. The range reaches its western limit in eastern Colorado, occurring uncommonly west of a line from Denver to Limon. Dickcissels are essentially absent from breeding sites farther west into the drier prairies and mountains.
Northern Range Limit
The northern limit of the Dickcissel’s breeding range corresponds closely with the prairie-parkland ecotone in the north-central United States and southern Canada. Dickcissels breed regularly in suitable habitat through southern and eastern South Dakota. In North Dakota, the range covers the southeastern half of the state, west to the Missouri River.
In Minnesota, the core breeding range is concentrated in the southwestern and southern counties, with scattered confirmed breeding north to Clay County. Breeding distribution becomes increasingly sporadic farther north and west, limited by the transition to forested habitats. There are few confirmed nesting records in the aspen parklands northwest of Minnesota’s prairie region.
The northern edge of the breeding range dips south again across Wisconsin, Michigan, and southern Ontario, with very localized breeding sites hugging the shores of Lake Huron, Lake Erie, and Lake Michigan. The limited availability of grassland habitat greatly restricts breeding populations in this region.
Eastern Range Limit
On the eastern side of its breeding range, Dickcissels occur across most of Missouri, while becoming more localized eastward through Illinois, Indiana, Ohio, Kentucky and Tennessee. The core breeding range extends east through most of Missouri, while becoming scattered in the oak-hickory forests of the Ozarks and absent from the Mississippi River bottoms.
Dickcissel distribution covers most of Illinois, though it is rare or absent from extensive forested areas in the south and sparsely scattered across northern Illinois. In Indiana, the range covers primarily the northern two-thirds, becoming quite localized south of the last glacial boundary. The range is concentrated in central and north-central Ohio, becoming localized and scattered in northeast Ohio.
Farther east, breeding distribution in Kentucky, Tennessee, and other Appalachian states is very patchy, restricted to scattered habitat sites such as reclaimed surface mines, open meadows within forests, and grassy fields along rivers. The limited availability of suitable open habitat greatly limits breeding populations.
Where does the Dickcissel winter?
The Dickcissel is one of the long-distance migratory songbirds of North America. Nearly the entire population winters in Mexico, Central America, northern Venezuela, and Colombia. A small number regularly reach south Florida and the West Indies. Dickcissels begin migrating south in late summer, with peak migration in September and October. Northward spring migration peaks in late April and May.
Mexico and Central America
Mexico hosts the majority of wintering Dickcissels, which occupy habitats ranging from agricultural fields to savannas, grasslands, and scrub. Highest densities occur on the Pacific Coastal Plain from Sonora to Chiapas, and through the interior in the Bajío region and Central Plateau. Lower numbers reach the Yucatán Peninsula and Veracruz.
In Central America, Dickcissels primarily occupy agricultural lowlands and savannas from Guatemala to Panama, with smaller numbers scattered across the Caribbean slope. Highest densities are found in the dry, thorn-scrub regions. Costa Rica and Panama represent the southern limit of most Dickcissel’s migration, though some may reach northern Colombia.
Caribbean and South America
Relatively few Dickcissels migrate as far south as northern South America. Their presence there is largely limited to the Caribbean coastal regions of Venezuela and Colombia, with highest numbers in the Venezuela llanos. Vagrants occasionally reach Trinidad and Tobago.
A small population regularly winters in southern Florida south to the Everglades, though numbers fluctuate annually. Breeding has been occasionally documented in Florida as well. The Bahamas host a minor wintering population, mostly on the island of Andros. Cuban records are primarily of birds passing through on migration.
How do latitude and habitat influence Dickcissel distribution?
The Dickcissel’s breeding and wintering ranges are shaped largely by the availability of suitable grassland and open scrub habitat. Both latitude and proximity to their preferred central grassland habitats influence densities across their range.
Breeding Range
During the breeding season, Dickcissel distribution centers strongly on the prairie grasslands of the Great Plains, with numbers diminishing toward the east and west. The arid shortgrass prairies marking the western limits of their range provide marginal habitat at best. Farther east, the gradual transition from tallgrass to mixed grass to shortgrass prairie influences breeding densities.
Farther eastward through the Midwest, habitat becomes more fragmented by forest, cropland, and urban development. The limited availability of grasslands and hayfields greatly reduces Dickcissel numbers, though breeding birds congregate in patches of suitable habitat.
Toward the northern limits, colder temperatures and a shorter growing season likely also play a role in reducing Dickcissel numbers, despite the presence of prairie. The small breeding population in southern Ontario relies on the moderating influence of the Great Lakes to persist.
Wintering Range
During the nonbreeding season, habitat use shifts somewhat from native prairie to tropical grasslands, savannas, scrub, and agricultural areas. However, higher latitudes and proximity to core grassland regions continue to influence winter distributions. Highest winter densities occur from Mexico’s Pacific Coast across to the interior highlands, transitioning to patchier distribution farther southeast into Central America.
The Caribbean slope and much of the Yucatán Peninsula provide marginal scrub habitat. The limited grasslands of the West Indies and Caribbean coastal South America support only small wintering populations. Again, latitude and climate likely play a role in reducing numbers farther south.
How has the Dickcissel’s range changed over time?
The conversion of native prairie to cropland initially expanded Dickcissel breeding habitat, leading to population boom in the late 1800s. However, populations declined sharply in the 1900s before rebounding somewhat in recent decades. The range itself has remained relatively stable, with fluctuations mainly occurring at the edges rather than sweeping contractions or expansions.
19th Century Range Expansion
In the early to mid-1800s, Dickcissel populations were centered on the tallgrass prairie region from Missouri and Iowa south to Texas. The conversion of prairie to grain farms beginning in the 1840s created ideal breeding habitat, allowing Dickcissels to expand their range north and east into Minnesota, Wisconsin, and Michigan as well as west into the shorter grass regions.
By the late 1800s, Dickcissel numbers had expanded exponentially across the Midwest and west to Colorado, taking advantage of the prevalence of small grain farms interspersed with patches of prairie. Breeding Bird Survey data indicates Dickcissels were likely at their peak distribution during this period.
20th Century Declines
In the early 1900s, populations began declining steadily, as cleaner farming methods and increased pesticide use reduced the seed and insect food sources Dickcissels rely on during breeding. Between the 1940s and 1970s, Breeding Bird Survey data showed population declines of over 2% per year across much of its range.
The core of the breeding range retracted west from Michigan, Wisconsin, and Minnesota back toward the Great Plains. Range edges also withdrew slightly, such as the eastern limits in Ohio and Kentucky. By the 1960s-70s, breeding range occupancy had shrunk by nearly 50% from its peak around the turn of the century.
Recent Stabilization
Since the 1980s, more sustainable agriculture practices and set-aside programs have helped stabilize Dickcissel populations. Numbers in parts of the Great Plains have returned to early 1900s levels. The breeding range has expanded slightly in some areas, such as eastward in Missouri and Kentucky, while continuing to decline in others.
Farther north in Minnesota, Wisconsin, and Michigan, breeding remains highly localized around scattered habitat patches. Despite some fluctuations, the overall breeding range has been relatively steady over the past 40 years, though densities continue to vary widely across the range.
Conclusion
The Dickcissel breeding range is centered on the prairie grasslands of the Great Plains, spanning from Texas to South Dakota and eastern Colorado. Highest breeding densities occur in optimal habitat across Nebraska, Kansas, Oklahoma, and surrounding regions. The range becomes patchier toward the east and west, limited by terrain and habitat.
During winter, Dickcissels occupy tropical grasslands, scrub, and agriculture from Mexico to Panama, with smaller numbers reaching the Caribbean, Florida, and Venezuela. Their distribution continues to be shaped primarily by the availability of open grassy habitat. Conversion of prairies initially expanded their range but more intensive farming later caused declines. With improved conservation, Dickcissel populations have stabilized across much of their range in recent decades. Understanding their habitat needs and range dynamics remains key for conserving this iconic grassland songbird.