appendix b final 2008 biological surveys of los angeles and long ...

9.0 Birds
changes in species number were associated primarily with the Waterfowl (grebes, ducks, and
geese) and Aerial Fish Forager (terns and pelicans) guilds (Figure 9.3-2). Although less
abundant in the Ports, Shorebirds (sandpipers, oystercatchers, and stilts) also were seasonal in
occurrence.
Waterfowl were more abundant from the second November survey through the April survey due
to increased abundances of Brandt’s Cormorant, Surf scoter, and Western Grebe as well as
less abundant species such as Bufflehead, Clark’s Grebe, Eared Grebe, Horned Grebe, Lesser
Scaup, Mallard, Pelagic Cormorant, Pied-billed Grebe, and Ruddy Duck (Appendix H-2).
Aerial Fish Forager numbers followed an opposite pattern with higher numbers in May through
July when Brown Pelicans return from offshore nesting areas and terns are at nesting sites at
the Ports (Section 9.4, Appendix H-2). Abundances were lower in January through April
coinciding with the period when Brown Pelicans are nesting at offshore Channel Islands and
terns have departed for wintering areas. California Least Tern, Caspian Tern, and Elegant Tern
nested at two sites in Los Angeles outer harbor (Section 9.4.2).
One species of shorebird, Black Oystercatcher, nested at the Ports and contributed to
seasonally higher abundances during spring-summer (Appendix H-2). Other shorebirds such as
Black-bellied Plover, Black Turnstone, Killdeer, Least Sandpiper, Sanderling, and Whimbrel
generally were more abundant during winter and/or spring.
While the seasonal patterns indicate that many species are migratory, the Gulls and Upland Bird
guilds were present in fairly consistent numbers throughout the year (Figure 9.3-2). Western
Gull was a dominant species during all surveys. Heermann’s Gull also was present each
survey, but was much less abundant during March through May. California and Ring-billed
Gulls were fairly common in winter and spring, whereas Herring and Mew Gulls were winter
visitors. Upland Birds, primarily represented by Rock Dove, were present in fairly consistent
numbers throughout the year (Figure 9.3-2).
A total of 20 species were observed during all or most surveys. These included the seventeen
water-associated birds: Brown Pelican; Brandt’s, Double-crested, and Pelagic Cormorants;
Great Blue and Black-crowned Night Herons; Snowy Egret; Mallard; Surf Scoter; Black
Oystercatcher; Western Grebe; Heermann’s and Western Gulls (and Ring-billed Gull on 19 of
the 20 surveys); and Caspian Tern (and Royal Tern on 19 of the 20 surveys). Three Upland
birds (American Crow, Rock Dove, and House Finch) and one raptor species (Osprey) were
observed during all surveys (Appendix H-2).
9.4 SPECIES COMPOSITION
9.4.1 Percent Guild and Species Abundance
Approximately 90 percent of the observed birds belonged to
three water-associated guilds: Aerial Fish Foragers, Gulls,
and Waterfowl (Table 9.4-1). The upland bird guild
accounted for approximately 6% of the observations. Other
guilds associated with land and water interface habitats
(shorebirds, wading/marsh birds) and raptors represented
less than 4% of the total observations. The ten most
abundant species over all surveys accounted for over 91% of
the bird counts.
The most abundant guild was Waterfowl (38.5%), with
Brandt’s Cormorant the most abundant waterfowl species and the second most numerous
2008 Biological Surveys of Los Angeles and Long Beach Harbors 9–3
April 2010