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Roosting and nesting habitats exhibit certain identifiable features, including large trees (those <br />with a trunk diameter of 12 inches or more (i.e., high tree basal area)), uneven aged tree stands, <br />multi- storied canopy, a tree canopy creating shade over 40 percent or more of the ground (i.e., <br />moderate to high canopy closure), and decadence in the form of downed logs and snags (standing <br />dead trees). Canopy closure is typically greater than 40 percent. <br />Owl foraging habitat includes a wide variety of forest conditions, canyon bottoms, cliff faces, <br />tops of canyon rims, and riparian areas. The owl occupies a broad geographical area, but does <br />not occur uniformly throughout its range. Instead, the owl occurs in disjunct localities that <br />correspond to isolated mountain systems and canyons. <br />Bonytail chub <br />The bonytail chub (Gila elegans), is a highly streamlined fish, dark on top, light below, often <br />very dark in clear waters and pale in turbid waters. Fins are dusky with yellow pigment near <br />base, preferring eddies and pools, not swift currents. The bonytail chub has a concave skull <br />arching into a nuchal hump predorsally with a long and slender snout that does not overhang the <br />upper lip. Scales often minute or absent from chest, stomach. Adults of seven years of age can <br />be 14 inches long and weigh more than one pound. Found historically throughout the Colorado <br />River Drainage however, in recent years bonytail have only been taken from the Green River in <br />Utah and lakes Havasu and Mohave. <br />Colorado pikeminnow <br />The Colorado pikeminnow (Ptychocheilus lucius), is a torpedo - shaped fish with an olive -green <br />and gold back, silver sides and white belly. The Colorado pikeminnow is endemic to the <br />Colorado River basin, where it was once widespread and abundant in warm -water rivers and <br />tributaries. Wild populations of Colorado pikeminnow are found only in the upper basin of the <br />Colorado River (above Lake Powell). Three wild populations of Colorado pikeminnow are found <br />in about 1,090 miles of riverine habitat in the Green River, upper Colorado River, and San Juan <br />River subbasins. The Colorado pikeminnow thrives in swift flowing muddy rivers with quiet, <br />warm backwaters and are primarily piscivorous, but smaller individuals also eat insects and other <br />invertebrates. These fish spawn between late June and early September and when they are 5 to 6 <br />years old and at least 16 inches long. Spawning occurs over riffle areas with gravel or cobble <br />substrate. The eggs are randomly splayed onto the bottom, and usually hatch in less than one <br />week. <br />Greenback cutthroat trout <br />The greenback cutthroat trout (Oncorhynchus clarki ssp.stomias), is a coldwater fish belonging <br />to the trout, salmon and whitefish family. They have dark, round spots on the sides and tail and <br />two colorful blood -red stripes on each side of the throat under the jaw, hence the name <br />"cutthroat." During the spring spawning season the entire belly may become crimson red. <br />Traditionally, greenback cutthroat trout typically weighed between 1 and 2 pounds, and did not <br />exceed 12 inches in length. Presently, size is dependent upon elevation and population size. <br />6 <br />