ARCHIVED REPORTS_1993_1 - Laserfiche WebLink

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I Suggested reasons for the decrease in the species' numbers include conversion of grasslands and open brushlands to agricultural croplands and the recent trend toward creation of larger fields and "clean farming" (i.e., the reduction of the fencerow vegetation used by shrikes and their prey) (Fraser and Luukkonen 1986, U.S. Fish and Wildlife Service 1987). Status in the Project Area. Loggerhead shrikes were observed perched in trees near the project site. The project site provides suitable foraging habitat but no nesting sites. Agricultural fences and utility lines on the perimeter of the project site provide perch sites. Northern Harrier Background. The northern harrier is either a permanent or winter resident over all of California, except in the Klamath, Cascade, and Sierra Nevada Ranges. Northern harriers nest in dense grasslands and wetlands and forage in wetlands, grasslands, and agricultural fields. Loss of grasslands and wetlands has contributed to the decline of northern harriers in California. Status In the Project Area. Northern harriers were observed foraging at the project site during both field surveys. Annual grasslands at the project site provide suitable foraging habitat but are considered unsuitable for nesting habitat because they are not dense or wet enough. Black -Shouldered Kite Background. Black -shouldered kites have a restricted distribution in the United States and occur only in California and along the Texas coastline. Black -shouldered kites are common in Central Valley lowlands. Black -shouldered kites nest in riparian and oak woodlands and forage in grasslands, pastures, agricultural fields, and wetlands, using nearby treetops for perching and nesting sites. Mice are the major prey item. During the early 1900s, the black -shouldered kite was almost extirpated from the United States through persecution (shooting) but has since made a successful comeback (Terres 1987). Status In the Project Area. A black -shouldered kite was observed foraging in annual grasslands at the project site during the February field surveys. The annual grasslands provide suitable foraging habitat for black -shouldered kites, but the project site does not support suitable nesting habitat. Ferruginous Hawk Background. Ferruginous hawks winter in California usually from October to March. A few individuals may summer in the extreme northeastern corner of the state (Grinnell and Miller 1944). Ferruginous hawks occur throughout the state in open terrain of plains and foothills where they feed on small mammals, reptiles, and insects. Ferruginous hawk populations are declining because of loss of breeding habitat and human disturbance. Status In the Project Area. A ferruginous hawk was observed foraging near the project site during the February field surveys. The project site, as well as annual grasslands throughout the state, provide suitable foraging habitat for wintering ferruginous hawks. Tricolored Blackbird Background. Tricolored blackbirds are permanent residents in the Central Valley from Butte County through Kern County and are found in scattered locations throughout the state. ER -93-1 - 40 - (9-27-93)