CREDIT; JACK WHITE. CALIF. FISH AND GAME COMM. 



CALIFORNIA CLAPPER RAIL 



Rallus longirostris obsoletus Ridgway 



KINGDOM Animalia 



CLASS Aves 



ORDER Gruiformes 



FAMILY Rallidae 



OTHER COMMON 



NAMES California King Rail, 



Red-breasted Rail, Marsh Hen (Grin- 



nell and Miller 1944). 



DATE 



Entered into SWIS to be determined 



Update to be determined 



LEGAL STATUS 



Federal: Endangered: (42 FR 36427, 14 July 

 1977). Migratory Bird Treaty Act of 3 

 July 1918 (40 Stat. 755; 16 U.S.C. 

 703-711) as amended 3 Dec. 1969. 

 Public Law 91-135. 



State: Endangered: California. 



REASONS FOR CURRENT STATUS 



Originally abundant locally within its limited 

 range, California clapper rail numbers and the 

 extent of its territory were much reduced before 

 market hunting was outlawed. Under legal pro- 

 tection, its population increased, and by 1944, 

 much of the former territory had been regained. 

 Exceptions were extensive areas of San Francisco 

 Bay marsh that had been converted to human use 

 (Bryant 1915, De Groot 1927, Grinnell and Miller 

 1944, Wilbur and Tomlinson 1976). 



This rail is vulnerable because the population 

 is divided into small, isolated colonies occupying 

 islands of suitable habitat that are separated by 

 long stretches of uninhabitable rocky or sandy 

 coast (Van Rossem 1929). There has been no in- 

 dication of change in status recently, except for 

 continuous attrition of the most productive habi- 

 tat in south San Francisco Bay by conversion of 

 marshes for other uses (Wilbur and Tomlinson 

 1976). The coastal marsh south of San Francisco 



1 



