2007 Annual Monitoring Report (pdf 16MB) - Bolsa Chica Lowlands ...

Bolsa Chica Lowlands Restoration Monitoring2007 Annual ReportThe heavy usage of the intertidal sand shoals in Zone 73 (inlet) at low tide by gulls, cormorants, terns,and pelicans is not captured by this survey, though observed regularly in the late afternoons at the site.The survey also cannot account for movement of birds into and out of the survey area from BolsaChica State Beach and from Inner and Outer Bolsa Bay.Gulls on sand shoal in the Full Tidal Basin.Flying birds were recorded in the habitat over which they were flying at the time of observation,though they may not necessary use that habitat on the ground. To look at species richness, all birdsrecorded as flying were disregarded and only birds on the ground considered. Species richness washighest in October in the salt marsh (38 species), inundated salt panne (33 species), mudflat (30species) and open water (29 species). In December species richness was greatest in open water (43species), mudflat (42 species), and salt marsh (38 species). All other habitats had 20 species or lessduring both periods.DiscussionThere were only two general avian surveys during Year 1: one in October which corresponded withbirds migrating through Bolsa Chica, and one in December which sampled the birds that overwinter atBolsa Chica. The most highly utilized habitats within the study area were inundated salt panne,mudflats, and open water. Shorebirds were the most abundant bird guild.On-going monitoring is expected to illuminate seasonal patterns of use within the system andinterannual variability. With only two surveys in place, interpretation of habitat use patterns remainssomewhat premature, though as would be expected mudflat, salt panne, and open water were heavilyutilized.Diversity within the study area is comparable to diversity observed at Batiquitos Lagoon during longtermmonitoring conducted using similar methods. The October 2007 survey at Bolsa Chica observed90 species. October surveys at Batiquitos Lagoon recorded between 80 to 92 species, with an averageof 88 species. Batiquitos Lagoon is a smaller site (approximately 2/3 the size) and includes morediverse habitats with a more balanced distribution.Merkel & Associates, Inc. 47