Chukars (Alectoris chukar) are a type of partridge found in parts of Eurasia and North America. They are a popular game bird and have been widely introduced outside their native range, including to the United States. There has been some debate over whether certain populations of chukars in the US should be considered native or introduced. This article will examine the evidence and arguments surrounding the native status of chukars in North America.
Quick Answer
Most authorities consider chukars to be non-native to the United States. Chukars are native to parts of Eurasia and were likely introduced to the US through a combination of purposeful releases for hunting purposes and accidental escapes from game farms. Feral populations are now established in parts of the western US.
Native Range of Chukars
Chukars are native to parts of southern Eurasia. Their natural range extends from the Balkans eastward across Turkey, the Middle East, Central Asia, and into China and Mongolia. Within this broad region, they inhabit rocky hillsides, mountain slopes, gorges, and cliffs in arid to semi-arid environments.
The native distribution of chukars is shown in the map below:
Figure 1. Native range of chukars (Alectoris chukar)
As can be seen, the native range of chukars covers parts of southeastern Europe, Turkey, the Caucasus region, Iraq, Iran, Afghanistan, Pakistan, India, Nepal, western China, and Mongolia. The species is absent from North America in its native distribution.
Introduction of Chukars to North America
Chukars are not considered to be a naturally occurring species in North America. They were first brought to the continent in the late 19th and early 20th centuries through a combination of purposeful introductions and accidental escapes.
The first introductions of chukars to North America took place in the late 1800s. Small populations were released for hunting purposes in parts of California, Nevada, Washington, and British Columbia between 1893 and 1901. These early introduction attempts had limited success.
More large-scale introductions followed in the 1920s and 1930s in the western US. Thousands more chukars, imported from their native range in Asia, were released by state game agencies in Washington, Oregon, California, and British Columbia during this period. The goal was to establish chukar populations for hunting recreation.
Additional releases occurred in subsequent decades, both authorized and unauthorized, contributing to the spread and establishment of feral chukar populations in parts of the western US. Accidental escapes from game farms or breeding facilities likely augmented these introduction efforts.
Table 1. Early introductions of chukars to western North America
Year | Location | Number Released |
---|---|---|
1893 | California | Unknown |
1901 | Nevada | 100 |
1910 | British Columbia | 239 |
1928 | Washington | 10,600 |
1929 | Oregon | 3,500 |
1933 | California | 1,800 |
As shown in Table 1, purposeful introductions of live chukars imported from Asia took place across the western US and Canada in the late 19th and early 20th centuries. The largest releases occurred in the 1920s and 1930s in an effort to establish huntable wild populations.
Current Distribution in North America
Following multiple introductions over the past century, feral chukar populations are now well-established in parts of western North America. Their current distribution covers areas of Washington, Oregon, California, Nevada, Idaho, Utah, Arizona, New Mexico, Colorado, Montana, Wyoming, and British Columbia.
Chukars occupy a variety of arid, open habitats within this range, including shrublands, grasslands, rocky cliffs and outcrops, and gorges. They are most common in upland areas at elevations between 600-6,000 feet. Chukars also utilize man-made structures like road cuts, quarries, and mine tailings.
The map below shows the current known distribution of chukars in western North America following introductions:
Figure 2. Current range of feral chukar populations in western North America
Populations are concentrated in the Columbia River Basin, Great Basin, and western Rocky Mountain regions. The highest densities occur in Idaho, Nevada, Utah, and Oregon. More isolated populations exist in Montana, Wyoming, Colorado, New Mexico, and Arizona.
Arguments for Native Status
While most biologists consider chukars to be nonnative to North America, there has been some debate over whether populations in the US may have originated from natural range expansions rather than introductions. Several lines of evidence have been used to argue that chukars may be native to parts of the western US:
Fossil Records
Fossil bones identified as chukars have been found in late Pleistocene archaeological sites in the southwestern US. The presence of these bones indicates chukars may have ranged into North America during the last ice age. However, the fossils have not been definitively dated and could represent more recent archaeological deposits.
Early Accounts
There are some early 19th century reports of chukar-like birds in parts of the western US, predating known introduction efforts. These include an 1828 account near the Columbia River and an 1866 record from Nevada. However, these sighting were often vague and inconclusive, making it difficult to confirm the presence of chukars independent of introductions.
Genetic Evidence
Mitochondrial DNA analysis of some US chukar populations found higher genetic diversity than would be expected from a rapid colonization through introductions. This higher diversity could reflect an earlier natural expansion into western North America. But other analyses have found low diversity consistent with rapid introduction. Findings remain inconclusive.
Habitat Suitability
Parts of the western US contain suitable arid, rocky habitat for chukars within their climatic tolerance. This suggests the region could have been colonized naturally without human assistance. But habitat suitability alone does not confirm native status.
Arguments Against Native Status
Despite these lines of circumstantial evidence, most biologists continue to consider chukars as nonnative to North America, for several reasons:
Lack of Historical Records
There is an absence of verifiable reports, specimens, or other records of chukars from North America prior to the documented introduction efforts in the late 1800s. Earlier accounts are considered unreliable. If chukars were native, their presence would presumably have been noted.
Isolation from Native Range
The western US is isolated from the nearest native chukar populations in Asia by formidable geographical barriers that likely would have prevented natural colonization. Chukars are not strong fliers capable of sustained overwater dispersal.
Genetic Uniformity with Asian Populations
Genetic studies show US chukar populations are nearly identical to and nested within the diversity of Asian chukars. This strongly points to origination from imported Asian stocks rather than natural colonization from a native North American population.
Documentation of Early Introductions
Records confirm that multiple deliberate introductions of chukars from Asia took place in the late 1800s and early 1900s in parts of the western US. These documented translocations are sufficient to account for the establishment of current US populations.
Limited Time for Natural Colonization
Any natural colonization across Beringia during the last ice age would have needed to occur within a window of roughly 13,000 years following glacial retreat. This is considered insufficient time for chukars to have dispersed across Asia and populated North America.
Conclusion
In summary, the preponderance of evidence strongly indicates that chukars were introduced to North America through human-assisted translocations starting in the late 19th century. Arguments that some populations in the US may have originated from earlier natural colonization across Beringia during the last ice age are not substantiated. Chukars are considered a nonnative game bird in the western United States, where feral populations now occur as the result of deliberate introductions and escapes from game farms. Management of the species as an exotic is recommended. Their native range remains confined to parts of Eurasia.