KEEN CONNECTS: Prarie Falcons make the Yakima River Canyon home

February 26, 2019

What bird is emblematic of the arid intermountain western United States? There are charismatic birds found in the western United States that are iconic: Merlin and Peregrine Falcons, for example, but they are also found in the Midwest and eastern sectors of North America, and even across the globe.

The Prairie Falcon, on the other hand, nests strictly in the western sector of United States, with a small representation in southern Canada and northern Mexico. The best locality to see Prairie Falcons near Ellensburg is in the Yakima River Canyon.

 

Mr. Andy Stepniewski, author of “The Birds of Yakima County, Washington” (1999), reported seeing a total of 21 juvenile Prairie Falcons on one day in the early ‘90s, from a single high vantage point in the Yakima River Canyon. Prairie Falcons do not build nests; instead, they scrape loose debris to form a small depression to hold eggs within a small rock cavity or crevice. Most cliff sites have some overhang that provides protection from storms and the hot sun. Most eyries also have a southern exposure.

Our nearby Yakima River Canyon begins about six and a half miles south of Ellensburg. It hosts the most diverse and the greatest abundance of raptorial birds within the state of Washington. The basalt cliffs, tall cottonwoods, meadow grasslands, and benches above the canyon provide nesting sites for birds of prey.

 

A study conducted for the Washington Department of Fish and Wildlife (WDFW) in the 1980s revealed over 125 nests of birds of prey in the canyon. The study documented these diurnal (daytime) birds of prey in order of decreasing number: American Kestrel, Red-tailed Hawk, Cooper’s Hawk, Golden Eagle, Prairie Falcon, Northern Harrier, and Ferruginous Hawk. Since that study, the Ferruginous Hawk has been extirpated and the Bald Eagle has become established as a breeding species within the canyon. Nocturnal species documented included: Great Horned Owl, Barn Owl, Northern Saw-whet Owl, and Western Screech-Owl. In addition, Peregrine Falcons, Merlins, Northern Goshawks, Sharp-shinned Hawks and Rough-Legged Hawks find winter quarters adjacent to or within the Yakima River Canyon.

There has been a decline in Prairie Falcon numbers in our canyon. I suspect we will never again see as many Prairie Falcons as Andy Stepniewski saw in the 1990s.

 

Reasons for the decline of Prairie Falcons in the canyon are open to debate. I suspect the decline is due to the conversion of shrub-steppe to agricultural crops; establishment of invasive species such as cheatgrass and knapweed; a decrease in the abundance of prey (such as Townsend’s Ground Squirrels); and changes in fire regimes within the canyon and surrounding shrub-steppe in the summer months.

When ground squirrels move underground to escape summer heat and drought, most Prairie Falcons leave their nesting areas in search of other prey. Horned Larks and Western Meadowlarks are important prey items in late summer and early autumn. However, shrub-steppe and grassland birds are also in steep decline, which could pull the number of nesting Prairie Falcons down. There are many deleterious and pernicious factors at play, and some may act synergistically. I am not sure we have a single smoking gun.

 

The male prairie falcon is smaller than the female. In the springtime Prairie Falcons preform phenomenally brilliant aerial nuptial flights and displays. These courtship flights rival anything I have seen in nature. The male, being smaller and with a lighter wing loading, performs faster and more elaborate nuptial flights — flying upside down, and in elliptical loop-the-loop flights. Many times you will hear this bird before it is seen.

 

Loud territorial and courtship calls are sometimes the only clue to its presence, because its sandy-brown plumage blends into the cliffs on which it nests. The smaller male can be distinguished from the female by its more rapid wing beats and shriller call.

 

There are several keys to identifying Prairie Falcons: first, it is an intermediate-sized falcon and similar to a Peregrine Falcon. It is easiest to get confused during the winter months, when Peregrine Falcons are encountered in the canyon, especially if the bird is backlit or in low light, or if there is cloud cover on a winter day.

 

Prairie Falcons have pointed wings and snappy wing beats. They are powerful and direct flyers. Their dorsal plumage color is sandy brown with whitish plumages below. The head shows a whitish supercilium, pale cheek, and narrow black malar. Juveniles have a bluish cere (fleshy, soft tissue covering the base of the upper mandible). Adults have a yellow cere. The tail is brown with faint pale bands. The blackish wing linings and axillars are diagnostic; if you see “black wing-pits” it is a Prairie Falcon.

Scientists have puzzled for centuries over how different groups of birds are related. Did birds that look physically alike, such as falcons and hawks, arise from a common ancestor, or did they attain those similarities independently? This line of inquiry was given an immense boost in recent years when an international research team unraveled the genetic codes of 48 species of birds.

 

The emerging results, including revised evolutionary phylogenetic trees, places falcons, parrots and songbirds on adjoining evolutionary branches. In an evolutionary scheme, falcons are sister to parrots and songbirds. When you see a falcon you are not seeing a hawk but rather a bird closely related to a lorikeet.

 

Personally, I hope we can come together to appreciate and recognize the full worth of the Yakima River Canyon which is why I volunteer on KEEN’s Board of Directors. Through appreciation emerges care and concern. The Yakima River Canyon is part of our wildlife legacy and heritage and KEEN has been working to celebrate it through our events like Get Intimate with the Shrub-Steppe, the Yakima River Canyon Bird Fest, and the Yakima Canyon Interpretive Center project. The Prairie Falcon is the quintessence, a star, within the Yakima River Canyon. And the canyon is a great gift.

 

Gerald W. Scoville is a board member of the Kittitas Environment Education Network.

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