West Mojave Plan FEIR/S - Desert Managers Group

Regulatory Status: California Species of Special Concern.Threats Affecting the Long-Eared Owl: Flood control projects can impact or convertriparian habitat. Habitat degradation and disturbance at nest and roost areas are potential threats.This includes degradation of adjacent open foraging habitat. The increase of great horned owlsand their predation of long-eared owls may be having an impact. Shooting remains a minorthreat.3.3.6.10 Prairie FalconLife History: The prairie falcon is found throughout the western Mojave Desert,although it generally avoids urbanized areas. Nests are located on cliffs in rugged mountainranges, often within ½ mile of a water source. Mountain ranges near agricultural areas also arefavored because of increased prey density near nest sites. In winter, birds disperse widely, andare joined by migratory birds from northern latitudes.Population Status in the Planning Area: Prairie falcons are widespread inmountainous areas of the planning area. Three sites are recognized as high-density nestinglocations: Red Mountain/El Paso Mountains, Robber’s Roost, and Newberry Mountains/GraniteMountains. In addition, a substantial population has been reported from the Mojave B Range ofthe Naval Air Weapons Station.Regulatory Status: California Species of Special Concern.Threats Affecting the Prairie Falcon: Human disturbance at certain prairie falcon nestsites is a threat. Urbanization surrounding an historical eyrie gradually degrades the foraginghabitat and increases disturbance at the nest site so that they are abandoned. New miningprojects occasionally threaten selected nest sites. Eggshell thinning due to ingestion of pesticidesmay be a problem.3.3.6.11 Southwestern Willow FlycatcherLife History: The southwestern willow flycatcher breeds only in riparian woodland,typically adjacent to or even over water. Surface water or saturated soil is usually present in oradjacent to nesting sites during at least the initial portion of the nesting period.Population Status in the Planning Area: Summering willow flycatchers appear to beknown from only two sites in the western Mojave Desert:(1) At Big Morongo Canyon Preserve, one nesting pair in 1981. Subsequent years'regular study, however, failed to reveal any further resident willow flycatchers. The birds' use ofthe site is evidently only ephemeral.(2) Along the Mojave River. Since the specimen from Oro Grande in 1920, twoobservations: one at Mojave Narrows Regional Park in 1990 and the second about one-quartermile downstream (north-northwest) of the Interstate 15 crossing in 1994 and 1995.Chapter 3 3-178