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WILDLIFE RIDGWAY’S RAIL CONTEXT Although often described as secretive, the endangered California Ridgway’s rail, the size and color of a small chicken, is easy to spot in marshes and mudflats around the Bay. All species that rely on tidal marsh habitat are affected by habitat loss, alteration, and stressors. But this rail, formerly California clapper rail, is especially affected because they use low marsh for foraging, depend on channelized marshes, and need mid-marsh and upper marsh areas for nesting and refugia from predators. The Estuary’s population of Rallus obsoletus obsoletus is much reduced compared to the 1970s. Fewer than 1,200 individuals may remain, making this species highly vulnerable to extirpation. As a federally endangered subspecies, the rail has also been the focus of extensive tidal marsh restoration efforts throughout the Estuary, as well as a number of management activities. The rail is an excellent indicator of tidal marsh health. INDICATOR This indicator measures the R I D G WAY ’ S R A I L of Ridgway’s rail declined in the North Bay between 2005 and 2008, but since then the trend has mostly been reversed. In the South Bay, density declined between 2006 and 2008, and apparently into 2009. Though no further decline has been seen since 2009, nei- ther is there clear evidence of a reversal. B AY . . S TAT U S . . North Bay: Fair South Bay: Poor . . . .T R E N D . . . . Mixed .....BENCHMARK..... Derived from regional average 2005-2007 In the South Bay, large-scale removal of invasive Spartina (especially the alterni- flora x foliosa hybrid) during the period 2006 to 2010 improved conditions for native plant species but also removed intact vegetation used by the rails. An increase in bay-wide rail numbers to 2005-2007 levels will require time for current habitat restoration efforts to provide mature, native tidal marsh, and for other manage- ment actions targeting rails to take effect. In the North Bay there was also a substantial decline from 2005 to 2008, though there was much less Spartina eradication in this region. Photo: Rick Lewis meet this ambitious goal will require an increase in tidal marsh habitat. Current management actions and activities are being directed at planting or maintaining important plant species that provide cover, refugia from predators, and locations for successful nesting. Those include gumplant (Grindelia stricta) and native cordgrass (Spartina foliosa). THREATS & CHALLENGES 0.4 2013 2012 2011 2010 2009 2008 2007 2006 2005 0 Poor 0.2 NORTH BAY Fair 0.6 SOUTH BAY Poor South Bay 0.8 Good Fair The goal of the Tidal Marsh Recovery Plan is to increase the current population size of Cutpoint Good rail vs Fair the 0.60 Ridgway’s in Estuary to approximately 5,500 individuals over a 50-year period. The Cutpoint Fair vs Poor 0.43 (for the period 2009-2011) best recent estimate for this region is fewer than 1,200 individuals. To Observed value 2011-2013 Results 0.47 Fair R I D G WAY ’ S R A I L P O P U L AT I O N I N D E X Good The biggest threats to the Ridgway’s rail are loss, fragmentation and alteration of habitat, loss of transitional habitat bordering tidal marshes (refuge for rails during high tides), changes in salinity, pollutants, human disturbance, and North Bay invasive plants and predators. 2013 2012 2011 2010 2009 2008 2007 2006 2005 density of birds per hectare as determined from comprehensive, standardized breeding season surveys conducted throughout the San Francisco Estuary since 2005. Surveys have been conducted by the Invasive Spartina Project, Point Blue Conservation Science, and various regional, state, and federal agencies. This indicator uses the most recent, state-of-the-art analysis by Point Blue for surveys carried out 2005-2013. The benchmark derives from the three-year mean density during 2005-2007. STATUS & TRENDS The density 55 RIDGWAY’S RAIL