PRAIRIE FALCON (Faico mexicanus) 



Anyone who has observed the aerial dive of the falcon, whether as part of 

 a mating ritual or in pursuit of prey, has witnessed one of the most thril- 

 ling and spectacular sights in the natural world. The stoop or dive of the 

 prairie falcon may exceed 125 miles per hour. Because these magnificent 

 birds stand at the top of the food chain and because of their popularity 

 among falconers, both the prairie falcon agd its rare counterpart, the 

 peregrine falcon, have declined In numbers in recent decades. Stream- 

 lined, missile-shaped birds with pointed wings, prairie falcons prey pri- 

 marily on smaller birds and rodents. The prairie falcon is a pale brown or 

 sandy-colored falcon. Its most distinguishing field marks are its "dirty 

 armpits" (distinctly dark areas in the bird's wingpits). Prairie falcons are 

 wide ranging but show a marked preference for cliff facings. They are rare 

 breeding inhabitants of the open cliffs and canyons of both Yellowstone 

 and Grand Teton. 



American Kestrel 



Leonard Lee Rue III 



BLUE GROUSE (Dendragapus obscurus) 



The blue grouse's scientific name translates "obscure tree lover." This 

 phrase describes well the appearance and habits of this species, for its 

 coloration provides excellent camouflage, and it is intimately associated 

 with conifers, particularly the Douglas-fir. The blue grouse breeds in 

 mixed woods or open conifers, but spends the entire winter in the conifers. 

 Conifers provide the grouse with both food and protective cover. During 

 the mating season the male grouse or cock attracts the female with a 

 series of booming or hooting sounds which are produced by the Inflation 

 of yellow throat sacs. The nest of the blue grouse is built on the ground, 

 often at the base of a tree or under a fallen log. The chicks, which hatch 

 in 26 days, develop rapidly and are able to fly efficiently in about two 

 weeks. Blue grouse are common permanent residents of the lodgepole 

 pine/spruce-fir and Douglas-flr/aspen complexes in both parks. 



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