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...the State of California for restoration and protection as a proposed Ecological Reserve. Though birds are among the primary beneficiaries of this effort, the avifauna of Ballona Wetlands has not been critically examined in more than 60 years. In an effort to guide future restoration projects, I present a review of bird taxa that have been extirpated, reestablished or that have newly colonized the Ballona area since 1900. This information should facilitate the development of target species to be monitored as the Ballona ecosystem is restored, and should help set local and regional restoration goals.
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The Ballona Valley, a large remnant open space area at the mouth of Ballona Creek that includes the Ballona Wetlands in southwestern Los Angeles County, is currently receiving an unprecedented infusion of funding for land acquisition and habitat restoration, coincident with the start of" construction on a 462-acre housing and commercial development ("Playa Vista"). In 2003, the California Wildlife Conservation Board acquired 483 acres--a little less than half the open space that remained in the valley through the 1990s--for conservation, including all the remaining intact salt marsh (Trust for Public Land 2003). This belatedly fulfilled a dream of local conservationists, birders, and public officials who have advocated for its protection since at least the early 1900s (Ellis 1926; Cooke 1946; Fuller 1955; Hise and Deverell 2000:220). As restoration projects to recreate or emulate historical natural conditions proceed, knowledge of the current and historical bird community is essential in determining appropriate restoration and conservation goals. Previous efforts at restoring degraded natural communities in the Ballona area have been marked by confusion over the composition of historical plant communities as well as their distribution across what is now a seriously degraded and much-diminished landscape (see Longcore et al. 2000).
Though much of the proposed restoration at Ballona has sought to improve conditions for birds (e.g., NAS 1986), synthesized information on the occurrence of birds and the composition of bird communities at Ballona is surprisingly sparse, being limited to a handful of unpublished surveys of varying quality. Not since the early 1940s (yon Bloeker 1943) has any attempt been made to analyze the records of local birders and collectors (either unpublished or published). Drawing from historical and current sources, including museum records and field notes of experienced observers, I present a list of regularly occurring species, and provide detailed accounts for species known to have been lost in the Ballona Valley since the early 1900s, those that have since reestablished populations, and those that have newly colonized the Ballona Valley as nesting or wintering species. Knowledge of this avifaunal change at Ballona should help establish benchmarks of successful restoration, and may serve as an example for reconstruction of lost natural communities elsewhere.
Methods and Site Description
The term "Ballona Valley" here refers to the lowlands from the Westchester Bluffs north across Ballona Creek to the rise in elevation that roughly follows Washington Blvd. in the Venice and Mar Vista neighborhoods of Los Angeles (see Fig. 1). I identify the 10-lane 405 Freeway as the eastern boundary, and thus include the communities of Marina del Rey, Mar Vista, Playa Vista and Playa del Rey. Historical collecting sites within the Ballona Valley include "Port Ballona" (an early bluff-top community at the northern end of the E1 Segundo Dunes just south of Playa del Rey c. 1880s, per Robinson 1939); "Ballona Harbor" (now Playa del Rey); "Del Rey" (now Mar Vista, per Robertson 1990); and "Venice Marshes" (presumably the northern portion of historic wetlands now covered by Marina del Rey, east of Venice). Modern birding areas were described by Cooper (2005d).
[FIGURE 1 OMITTED]
I consider taxa to be current breeders if one or more pairs have nested successfully for at least two consecutive years. Likewise, I consider winter residents to be any taxa for which two or more individuals have been present through the winter months for at least two consecutive years in the past five years. In one case (Elegant Tern) I consider the species to be a non-breeding summer resident, since large numbers (hundreds) are present continuously from early spring through fall. Taxa are considered "extirpated" if they once maintained consistent breeding or non-breeding populations in the Ballona Valley but no longer do. "Reestablished" taxa have been extirpated in at least one role (winter, summer or both) for a period of several decades, but have resumed breeding, summering and/or wintering since the mid-1900s (the start of consistent record-keeping). "Colonists" are defined as any taxa that have established a consistent breeding or wintering population since the mid-1900s (and that occurred only as transients or vagrants, if at all, prior to this).
Because of the lack of standardized historical survey data during migration periods, taxa known only as transients are not treated here (see Cooper 2005c for a complete checklist), even though it is clear that many birds scarce or absent today were once frequently observed transients (e.g., Fulvous Whistling-Duck Dendrocygna bicolor). I also omitted the Great Horned Owl Bubo virginianus, given its strongly nocturnal habits. I do not treat the distinctive avifauna of the outer jetties, the breakwater, and the inshore marine environment at Playa del Rey, nor do I include the avifauna of residential Westchester on the bluffs to the south of the Ballona Valley, which, owing to its mature trees and landscaping, has developed a woodland-like avifauna distinct from that of the Ballona Valley (e.g., wintering Townsend's Warbler Dendroica townsendi and Dark-eyed Junco Junco hyemalis).
Results and Discussion
A list of known regularly wintering, summering, and year-round resident birds in the Ballona Valley is presented in Table 1. Between the early 1900s and spring 2005, the data indicate that 38 taxa were extirpated from the Ballona Valley in at least one role, with 11 having since become reestablished in one or more roles. Twenty-two species have newly colonized the Ballona Valley either as summer or winter residents, including four non-native taxa. Ten species considered "data-deficient" may have maintained populations at Ballona prior to 1900 but are known only from scattered reports or specimens; several were treated as present by von Bloeker (1943) but are possibly attributable to the adjacent E1 Segundo Dunes, described below.
In the following species accounts, current local status is followed by historical status. Species order follows the American Ornithologists' Union Checklist of North American Birds (A.O.U. 1998) and the most recent supplement (A.O.U. 2004). Standard abbreviations for museums are LACM (Natural History Museum of Los Angeles County), MVZ (Museum of Vertebrate Zoology, University of California, Berkeley), and WFVZ (Western Foundation of Vertebrate Zoology, Camarillo, California). Other frequently-used abbreviations include BFM (Ballona Freshwater Marsh at Playa Vista, constructed 2003), CBC (Christmas Bird Count), LACBBA (Los Angeles County Breeding Bird Atlas, data housed at LACM), and PdR (Playa del Rey, exact location unspecified). Where possible, sight records are included only if published in Audubon Field Notes/(North) American Birds (hereafter "AFN") or in the Western Tanager ("WT"), or if the observer is known to the author.
A handful of dedicated observers have kept field notes from regular visits to the study area for 5+ years, including Kimball L. Garrett (KLG; early 1970s to present), Robert Shanman (RSh; monthly from 1977 to 1987) and Art Pickus (AP; 1993 to 1998) along lower Ballona Creek; Barbara O. Courtois at the western Ballona Wetlands (BOC; 1998 to present); Chuck and Lillian Almdale at Ballona Lagoon (CLA; monthly from 1996 to present); and Russell and Dorothy Stone in the Westchester/Playa Vista area (RDS; 1996 to present). Other observers who have contributed numerous previously unpublished sight records to me directly, or to Kimball L. Garrett ("LACM files"), are cited below by name, or in the case of regular contributors Richard Barth, David Bell, Kevin Larson and Don Sterba, by initials.
Extirpated and Reestablished Taxa
Brant Branta bernicla. Extirpated as a winter resident; now an occasional spring transient (l-2/yr. early Feb.--late May); casual in summer and winter. Several spring sightings have involved birds in the tidal channels of the Ballona Wetlands (including a group of six on 03 Apr. 2001, BOC), indicating that Brant may still occasionally attempt to use Ballona as a stopover site. Two summer/fall records include sick or injured birds in 1980 (H. Brodkin, LACM files) and 1996 (DS). The Brant was historically much more common along the coast of southern California with birds in Los Angeles County wintering on kelp beds just offshore (Willett 1912, 1933), a phenomenon that no longer occurs. Though omitted by yon Bloeker (1943), this may have been an oversight; groups of up to 12 birds attempted to winter at Ballona as late as the 1950s (WT 12:22; AFN 5:225; WT 18:23; AFN 7:234), and singles were recorded on the Los Angeles CBC through the 1950s (NAS 2002). One modern (post-1950s) wintering attempt involved what was presumably the same bird on 03 Dec. 2002 (BOC) and 12 Jan. 2003 (KL).
Northern Shoveler Arias clypeata. Extirpated, then reestablished as a winter resident; currently fairly common in fall and winter at BFM; uncommon to rare elsewhere. Since the creation of BFM in 2003, fall transients have appeared at the end of August in 2003 and 2004, building to several dozen birds by midwinter (Cooper 2005a). I observed dozens feeding on the flooded saltpan of the Ballona Wetlands after heavy rains in Jan. 2005. The Northern Shoveler was not recorded by yon Bloeker (1943) but was likely overlooked; early authors (e.g., Grinnell 1898, Willett 1933) have it common or abundant throughout coastal southern California, and a count of 200 presumably wintering birds was made at PdR on 05 Feb. 1947 (WT 13:28). A dramatic decline in the Ballona Valley apparently occurred after the 1950s (Table 2), and between the early 1970s and 2003, the species was recorded just eight times (RSh, KLG, AP).
Northern Pintail Anas acuta. Extirpated as a breeding resident; reestablished as a winter resident; now uncommon in migration and winter. The first southbound birds trickle through in late August (two along Ballona Cr. 21...
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