CALIFORNIA CLAPPER RAIL Rallus longirostris obsoletus (Ridgway) 



Order: GRUIFORMES Family: RALLIDAE 



Distinguishing characteristics : Like other races of clapper rails, it has a gray-brown 

 back, breast and upper belly tawny, flanks dark gray barred with white, tail short with 

 white below. Hen-like in action and has long legs. Bill, legs, and feet larger and color 

 of plumage more grayish than light-footed clapper rail. 



Present distribution: Resident in salt marshes of San Francisco Bay and Moss Landing . 

 Casual along the coast of central western California at Tomales Bay, Humboldt Bay, 

 Bolings Bay, and Morro Bay. Present range about the same as earlier distribution 

 except that smaller segments of suitable habitat remain and further inroads may be 

 anticipated. 



Former distribution : About the same as today except more restricted now by habitat losses . 



Status : Vulnerable because of restricted habitat which is rapidly decreasing . It depends 

 on salt and brackish tidal marshes with an abundant growth of cordgrass (Spartina 

 foliosa ) and pickleweed (Salicornia virginica ) . It also needs the quality of water which 

 supports mollusks and other small invertebrates as food items found in the mud bottom 

 sloughs . 



Estimated numbers : Total population is not known. Two or three pairs per 100 acres 

 of good habitat is estimated on basis of call notes heard. 



Breeding rate in the wild : Birds are reported to lay from 5 to 14 eggs per clutch. 



Reasons for decline : Population decline due to a reduction in salt marsh habitat and 

 pollution causing a reduction in habitat and food supply . Filling of bays and estuaries 

 for urban development is causing the biggest decline in suitable habitat, and this is 

 particularly true in the San Francisco Bay area where most of the remaining birds are 

 resident. 



Protective measures already taken : The species is protected by Federal and State law . 

 Abate water pollution wherever possible for this species as well as other water-associated 

 birds . Establishment of South Francisco Bay National Wildlife Refuge and acquisition of 

 Tubbs Island by The Nature Conservancy are beginnings toward habitat preservation. 

 A Bureau of Sport Fisheries and Wildlife research biologist is working part-time on this 

 bird. 



Measures proposed : Acquisition and/or agreements with property owners to retain 

 suitable marsh habitat for this and other water-associated birds. Further improvement 

 in controlling water quality in problem areas . 



Number in captivity : Unknown . 



Breeding potential in captivity: Unknown . 



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