2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...

Bolsa Chica Lowlands Restoration Monitoring
2008 Annual Report
Future Full Tidal Basin
A total of 9,105 individual birds (113 species) were counted in the 104-ha FFTB in 2008. The most
abundant guilds in the FFTB were upland birds, dabbling ducks, and shorebirds, respectively. The
most abundant upland bird was Belding’s Savannah sparrow that utilized the pickleweed-dominated
salt marsh and house finch that utilized the weedy uplands available in this area. These zones are dry
and highly disturbed in some areas. The ponded water within Zones 38, 63, and 30 was utilized by
dabbling ducks and shorebirds. American coot is also very abundant in this region.
Seasonal Ponds
The 50-ha Seasonal Ponds were utilized by 8,241 individual birds during the 2008 surveys,
representing 92 species. These ponds are a very important habitat for waterfowl, shorebirds, and
Belding’s Savannah sparrow. Zone 11 makes up the largest portion of the Seasonal Ponds, supports
the most diverse habitats, and is the least disturbed of the Seasonal Ponds zones and as a consequence
most bird activity was focused on this zone. The degree of inundation by rainfall fluctuates from year
to year, but generally it provides a mix of shallow water, salt panne, riparian forest, freshwater marsh,
and salt marsh.
The most abundant guilds in the Seasonal Ponds were shorebirds and dabbling ducks. Western
sandpiper was the most abundant shorebird, representing 67.9% of all shorebirds and 30.1% of all
birds observed in this area. This area was also occupied by species such as the black-bellied plover,
semipalmated plover, American avocet (Recurvirostra americana), black-necked stilt; the latter two
nested in the Seasonal Ponds. The most common dabbling ducks were the northern shoveler, gadwall
(Anas strepera), and American wigeon, indicating the importance of the shallow water in the inundated
salt panne for foraging and the exposed salt panne for resting. The Seasonal Ponds also support
considerable expanses of pickleweed that were heavily utilized for nesting by Belding’s Savannah
sparrow.
The Seasonal Ponds are much more heavily used by shorebirds during high tide, when the mudflats of
the FTB are no longer exposed and large flocks of sandpipers, black-bellied plover, and semipalmated
plover move over the berm into the ponds. This condition is not reflected in this dataset.
Muted Tidal Basins
The 77-ha MTB was the least utilized of all the survey areas, with the most abundant guilds being
shorebirds and upland species. The MTBs had a total of 4,633 individuals (95 species) during the
2008 surveys. Western sandpiper, black-bellied plover, and killdeer were the most abundant shorebird
species, and all utilized areas of open mudflat and salt panne primarily at the western ends of the
MTBs. As with the Seasonal Ponds, the MTBs were much more heavily used by shorebirds at high
tide, when mudflat was lost in the FTB but remained in the MTBs due to the muting by, or continued
closure of, the tide gates.
The most abundant upland species during the surveys were Belding’s Savannah sparrow and house
finch. The MTBs are an important area for Belding’s Savannah sparrow nesting, providing large
expanses of pickleweed. In 2008, there was standing water in much of the MTBs due to the opening of
the west MTB to the FTB and subsequent flow into the central and east MTBs, however Belding’s
Savannah sparrow usage remained high.
The ponded water in the MTBs was also utilized by least tern and Forster’s tern for foraging.
Merkel & Associates, Inc. 83