(Spartina foliosa), typifies this community 

 (Figure 3.10). Cordgrass has proven easy to 

 monitor (Zedler 1983b), amenable to 

 transplantation (Zedler 1984a), and 

 responsive to manipulative experimentation 

 (Covin 1984). Still, our knowledge of the 

 total community is incomplete. Insects that 

 live in and on the cordgrass are just beginning 

 to be studied (Figure 3.11; Covin 1986). 

 With new investigations, species that are new 

 to science are discovered (e.g., Incertella sp. 

 and Cricotopus sp., Figure 3.11). Both of 

 these tiny insects have larvae that live within 

 the leaves of cordgrass (J. Covin, SDSU, pers. 

 comm.). Horn snails, lined shore crabs 

 (Pachygrapsus crassipes), and yellow shore 



crabs (Hemigrapsus oregonensis) are 

 abundant, but their habits are not well known. 

 They feed on the algal mats and detritus and 

 are themselves eaten by the larger marsh 

 birds. 



No animal characterizes the lower marsh 

 better than the light-footed clapper rail 

 (Figure 3.12; Jorgensen 1975; Zembal and 

 Massey 1981a,b; Massey et al. 1984, Zembal 

 1990, Zembal 1991). Jorgensen's (1975) 

 study at Tijuana Estuary assessed the birds' 

 occupancy, nesting, and foraging in five 

 habitat types (high marsh, middle marsh, 

 saltwort-annual pickleweed, short cordgrass, 

 and tall cordgrass). 



Figure 3.10. The cordgrass community, showing the fiddler crab (right) and the lined shore crab 

 (in burrow). California horn snails are attached to the cordgrass stems and on the mud. A 

 California least tern is poised, ready to dive for fish in the channel. Mclntire collection, © 1986 

 by Zedler. 



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