The Taxonomy, Distribution, and Status of Coastal California Cactus Wrens
WESTERN BIRDS Volume 21, Number 3, 1990 THE TAXONOMY, DISTRIBUTION, AND STATUS OF COASTAL CALIFORNIA CACTUS WRENS AMADEO M. REA, San Diego Natural History Museum, P. O Box 1390, San Diego, California 92112 KENNETH L. WEAVER, 1113 SenwoodWay, Fallbrook,California 92028 The southerncoastal sage scrub is a distinctiveplant communityof southernCalifornia (Munz and Keck 1959, Mooney 1977). Beginningvery narrowlyin the Santa Barbararegion, it is bestdeveloped in Ventura,Los Angeles,Orange, and San Diegocounties, and endsin northwesternBaja California,where a differentplant assemblage,the maritimedesert scrub, begins(Thorne 1976). One very prominentfeature of coastalsage scrub is thicketsof cactus,including the CoastalCholla, Opun tia prolifera, and two speciesof prickly-pears,Opuntia littoralis and O. oricola. The coastalsage scrub is the primary habitat of two birds, the California Gnatcatcher, Polioptila californica californica, and the San Diego Cactus Wren, Campylorhynchusbrunneicapillus sandiegensis, that are decliningrap- idlybecause of lossof habitatto urbanization.(For explanationof variations in the spellingof the CactusWren's scientificname, see Appendix 1). This paper hasfour goals.First, we presentthe charactersdistinguishing C. b. sandiegensisas a validsubspecies distinct from adjacentraces of Baja Californiaand the interiorcontinental deserts. The charactersare givenin sufficientdetail that anyone with a specimenin hand shouldbe able to identifyit. Second,we evaluatethe taxonomicstatus of the CactusWrens occupyingVentura, Los Angeles,and Orange counties.In the original description (Rea 1986:119), these were referred to as less typical sandiegensis,and the birdsfrom the San FernandoValley, Los Angeles Co., were called anthonyi (Phillips 1986:120). Third, we analyze the habitatrequirements of C. b. sandiegensis.And finally,we presentcensus data from the last ten years demonstratingthe rapid declineof the San Diego CactusWren due to habitatloss.
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