broadest elevational range of all the salt 

 marsh species. It is also a species of broad 

 geographic range, occurring on the Pacific 

 Coast from Puget Sound, Washington, to the 

 southern tip of Baja California, Mexico 

 (Macdonald and Barbour 1974), and on the 

 Atlantic Coast. 



A small but significant bird finds its 

 preferred habitat within pickleweed- 

 dominated marshes. Belding's Savannah 

 sparrow (Figure 3.7) is listed by the State of 

 California as an endangered species. It builds 

 its nest low to the ground, often under a 

 pickleweed canopy but sometimes in saltgrass 

 (Distichlis spicata) or shoregrass. The birds 

 perch on the taller plants and defend 

 territories throughout most of the summer. 

 They eat insects in the marsh, but often fly to 

 creek or channel banks or even to the beach to 

 feed (B. Massey, pers. comm.; and A. White, 

 pers. comm.) Studies of their behavior, 

 responses to disturbance, and habitat 

 preferences have been conducted by White 

 (1986). Interannual variations in population 

 sizes of the Belding's Savannah sparrow are 

 considered in the final section of this chapter. 



Although pickleweed forms monotypic 

 canopies in many of the region's lagoonal 

 wetlands, i.e., those that close to tidal flushing 

 on a fairly regular basis, it is usually mixed 

 with several other succulents at Tijuana 

 Estuary. Before 1984, arrow-grass 

 (Triglochin concinnum) and sea-blite (Suaeda 

 esteroa) were common cohabitants, and 

 saltwort (Batis maritima) and annual 

 pickleweed (Salicomia bigelovii) dominated 

 areas that were poorly drained. The latter two 

 species were most abundant around intertidal 

 pools of the middle marsh (Table 3.2, Figure 

 3.8). Composition in this part of the marsh 

 has changed greatly since 1980 (Chapter 5). 



The animals of the midmarsh elevations 

 are abundant and rich in species. Part of the 

 reason is dependable moisture, and pari is the 

 availability of food. Algae are everywhere, in 

 pools and under the salt marsh canopy (Zedler 

 1980, 1982a). In winter, filamentous green 

 algae dominate the epibenthos, and in summer, 

 filamentous blue-greens form dense tufted 

 mats over the soil and plant stem bases 

 (Figure 3.9). Over 70 species of diatoms 

 occur within these filamentous mats (Table 

 3.3, Zedler 1982a). 







* 







■*>; 



mm w 



The animals that utilize these foods include 

 Ephydrid flies, whose larvae occur on 

 decaying plant matter; California horn snails 

 (Cerithidea californica); amphipods; and 

 snails (Assiminea and Melampus, Figure 3.9). 

 High concentrations of insects, especially 

 water boatmen (Trichocorixia spp.), occur in 

 the pools. They feed on the algae and in turn 

 provide food for the California killifish 

 (Fundulus parvipinnis), which spawn and 

 develop in these pools (Fritz 1975). 



A variety of birds forage in the midmarsh 

 habitat. Common are the willet 



(Catoptrophorus semipalmatus), marbled 

 godwit (Limosa fedoa), long-billed curlew 

 (Numenius americanus), great blue heron 

 (Ardea herodias), common egret 

 (Casmerodius albus), and Belding's Savannah 

 sparrow. 



Figure 3.7. Belding's Savannah sparrow with 

 ground nest in shore grass. Mclntire 

 collection, © 1986 by Zedler. 



The lower marsh of Tijuana Estuary is the 

 most well-studied habitat of the entire 

 system. The dominant plant, Pacific cordgrass 



33 



