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<br />projects, and urbanization. In some parts of its breeding range, pesticide use may have affected
<br />the yellow - billed cuckoo's prey base — injurious pest insects such as tent caterpillars, which tend to
<br />occur in cyclic outbreaks.15 1s Only one confirmed nesting occurrence was recorded in western
<br />Colorado (the Yampa River near Hayden) during Colorado Breeding Bird Atlas surveys from 1987
<br />through 1994.' The Colorado Natural Heritage Program' lists one record of yellow - billed cuckoo in
<br />western Colorado in La Plata County. Since the 1990, only one to two unofficial yellow - billed
<br />cuckoo observations, and no nesting reports, have occurred annually in western Colorado, mostly
<br />from the Uncompahgre River and Grand valleys.'
<br />The preferred habitat of yellow - billed cuckoo is low elevation river corridors. They nest in old- growth
<br />cottonwood forests or woodlands with dense, scrubby understories of willows or other riparian
<br />shrubs. Studies in California indicate this species may need extensive stands of riparian forest
<br />for nesting success.' Potential habitat adjacent to the Bear Mine on the North Fork River is only
<br />marginally suitable for this species due to the low density of mature cottonwoods, lack of significant
<br />cottonwood canopy, and lack of substantial shrub understory. The stretch of the North Fork River
<br />adjacent to Bear Mine's area of permitted surface disturbance is channelized due to the proximity of
<br />State Highway 133 to the north and steep hills to the south. These factors limit the floodplain and
<br />the development of riparian woodlands and forest to a narrow corridor. Given the availability of
<br />more suitable nesting habitat a few miles downstream where several reaches of the North Fork
<br />River support substantial cottonwood galleries, and given the low abundance of this species in
<br />western Colorado and the low likelihood of it selecting the marginal habitat near Bear Mine, renewal
<br />of the Bear Mine permit is not likely to cause measurable effects to yellow - billed cuckoo.
<br />Canada lynx
<br />The lynx was listed as a threatened species in 2000 at Federal Register 65(58):16051- 16086.
<br />Although it was never abundant, the lynx has historically occurred in appropriate habitat in upper
<br />montane and subalpine zones throughout central Colorado. 17 Re- introductions of lynx in the state
<br />have met with some success, with CDOW reporting about 47 percent survivorship and moderate to
<br />high reproductivity (23 possible mating pairs) of the 204 animals released since 1999. Designated
<br />critical habitat for lynx is currently being proposed at Federal Register 70(216):68294 -68328 by
<br />USFWS in portions of Maine, Minnesota, Montana, Idaho, and Washington. Although no designated
<br />critical habitat for lynx is being proposed in Colorado, USFS and CDOW have identified potential
<br />lynx habitat statewide based on vegetation data, including denning, winter foraging, and "other" lynx
<br />habitats.
<br />Primary lynx habitat in Colorado consists of coniferous forests of spruce and fir or lodgepole pine.
<br />Secondary habitat consists of aspen or Douglas -fir mixed with primary coniferous habitat, between
<br />8,000 and 11,500 feet elevation. Lynx typically forage in uneven -aged forests with shrubs or small
<br />trees that provide habitat for snowshoe hares, their primary prey. Small forest openings with low
<br />15 Hughes, J. M. 1999. Yellow- billed Cuckoo (Coccyzus americanus). In The Birds of North America, No. 418 (A. Poole and F. Gill, eds.).
<br />The Academy of Natural Sciences, Philadelphia, and the American Ornithologists' Union, Washington, D.C.
<br />16 Ryser, F. A., Jr. 1985. Birds of the Great Basin: a natural history. Reno: University of Nevada Press. 604 pp.
<br />17 Seidel, J., Andree, B., Berlinger, S., Buell, K., Byrne, G., Gill, B., Kenvin, D., Reed, D.. 1998. Draft strategy for the conservation and
<br />reestablishment of lynx and wolverine in the southern rocky mountains. Colorado Division of Wildlife, Denver, Colorado.
<br />18 Shenk, T. 2006 (Colorado Division of Wildlife Biologist). 2006. Lynx update, March 12. Available at
<br />http: // wildlife. state .co.us /NR/rdonlyres /432BB4E3 -271 F- 4A10- 904F- E6288B9CF1 E1 /0 /LynxUpdateMar122006.pdf.
<br />. 10 Ruediger, Bill, Jim Claar, Steve Gniadek, Bryon Holt, Lyle Lewis, Steve Mighton, Bob Naney, Gary Patton, Tony Rinaldi, Joel Trick,
<br />Anne Vandehey, Fred Wahl, Nancy Warren, Dick Wenger, and Al Williamson. 2000. Canada lynx conservation assessment and strategy.
<br />2nd Ed. USDA Forest Service, USDI Fish & Wildlife Service, USDI Bureau of Land Management, and USDI National Park Service.
<br />Missoula Montana.
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