Randy T. Larsen and Dr. Jerran T. Flinders, Integrative Biology
The Chukar (Alectoris chukar) is a medium-sized gallinaceous bird native to the Middle East and Asia first released in North America in 1893 in Illinois (Cottam et al. 1940). The sheer scale of subsequent releases is astonishing. Between 1931 and 1970 over 800,000 birds were released in 41 states (Hawaii included) and six Canadian provinces (Christensen 1970). Many of the initial introductions failed; however, wild populations were noted in a few western states as early as the 1940’s (Christensen 1996). Currently, persistent self-sustaining wild populations are found in California, Nevada, Arizona, Utah, Colorado, Wyoming, Idaho, Montana, Oregon, Washington, Hawaii and British Columbia, Canada (Christensen 1996). Chukars now occupy roughly 252,800 square kilometers of habitat in North America and an additional 578 square kilometers in Hawaii on the islands of Maui, Lanai, Molokai, Oahu, Kauai, and Hawaii (Christensen 1996).
Despite over 60 years of existence in western North America, much remains to be learned about the broad conservation implications of Chukar Partridge in the United States. My objective is to investigate two main themes relative to ecosystem-level impacts of Chukars.
Seed Dispersal
Many studies from the New World have documented the importance of exotic plants such as cheat grass (Bromus tectorum) and red-stem filaree (Erodium cicutarium) to Chukars. Cheatgrass has caused a tremendous amount of problems in the United States and is considered by some to be the most significant plant invasion in North America ((D’Antonio & Vitousek 1992).
To determine if Chukars disperse seed, I collected 261 droppings from western Utah during all four seasons of the year from three distinct study areas; these droppings were then planted in greenhouse flats and any seeds present allowed to germinate. Seedlings were removed upon identification. Only eight plants germinated; no cheatgrass was found to germinate. Apparently, Chukars do not disperse cheat grass or other exotic plants to any great extent.
Guzzlers
To increase populations of Chukar for hunting, state wildlife agencies and hunters have funded the installation of thousands of guzzlers across the west. These artificial water catchments are placed in desert regions to catch precipitation, store it, and provide water to wildlife during the summer months. Native species of wildlife are thought to benefit from the installation of these water sources, but limited research has been done to verify this belief. We utilized motion-sensing cameras placed at guzzlers designed for Chukars to photograph all species using guzzlers in an effort to determine what other species appeared to benefit.
At total of 26 species were photographed (Appendix A); interestingly, only three of the species are exotic—the vast majority are native species. Although preliminary, these results reveal that native species of wildlife make use of and presumably benefit from water provided from guzzlers developed largely to increase Chukar populations.
Chukars appear to be a relatively benign, if not beneficial, exotic species. They consume large amounts of exotic plant seed; yet Chukars do not seem to disperse cheat grass or other exotics to any large degree. Relatively few exotic species have been documented using artificial water sources. Science has yet to document major negative conservation implications of Chukars in the United Sates.
Appendix A (Larsen unpublished data)
Native Birds
Chipping Sparrow (Spizella passerina)
Lark Sparrow (Chondestes grammacus)
Mourning Dove (Zenaida macroura)
House Wren (Troglodytes aedon)
Rock Wren (Salpinctes obsoletus)
Western Meadowlark (Sturnella neglecta)
Black-billed Magpie (Pica hudsonia)
Lazuli Bunting (Passerina amoena)
House Finch (Carpodacus mexicanus)
Sage Thrasher (Orescoptes montanus)
Blue-gray Gnatcatcher (Polioptila caerulea)
Exotic Birds
Rock Dove (Columbia livia)
Chukar Partridge (Alectoris chukar)
Native Mammals
Bobcat (Lynx rufus)
Western Spotted Skunk (Spilogale gracilis)
Striped Skunk (Mephitis mephitis)
Black-tailed Jackrabbit (Lepus californicus)
Desert Cottontail Rabbit (Sylvilagus audoboni)
Coyote (Canis lantrans)
Kit Fox (Vulpes macrotis)
Gray Fox (Urocyon cinereoargenteus)
Least Chipmunk (Eutamias minimus)
Desert Woodrat (Neotoma lepida)
Badger (Taxidea taxus)
Pinyon Mouse (Peromyscus truei)
Exotic Mammals
Red Fox (Vulpes vulpes)
Literature Cited
- Christensen, G.C. 1970. The Chukar Partridge: its introduction, life history, and management. Biological Bulletin 4, Nevada Department of Fish and Game, Reno.
- ______. 1996. Chukar (Alectoris chukar). In: A. Poole and F. Gill, editors, The birds of North America No. 258. The Birds of North America, Inc., Philadelphia, PA.
- Cottam, C., Nelson A.L. and L. W. Saylor. 1940. The Chukar and Hungarian partridges in America. U.S. Fish and Wildlife Leaflet BS-159, Washington, D.C.
- D’Antonio, C. M., and P. M. Vitousek. 1992. Biological Invasions by Exotic Grasses, the Grass/Fire Cycle, and Global Change. Annual Review of Ecology and Systematics 23:63-87.