The unifying theme of this fall's reports of rare birds is an incipient invasion of mountain species. Look for Clark's Nutcrackers, Red-breasted Nuthatches, Pine Siskins, Townsend's Solitaires, and Red Crossbills. Stories from outside the county, like that of flocks of Scrub Jays crossing the open desert of northern Arizona, suggested that many irregularly irruptive species are moving en masse, perhaps driven by the drought and fires plaguing much of the Rocky Mountains. Though the magnitude of the invasion may be less than in 1996-1997, it still offers the promise of the most interesting winter birding in San Diego County since we initiated the atlas.
Storm-Petrels are so strictly pelagic that few of us have ever seen one from land. This fall, though, Jim Coatsworth saw a Black Storm-Petrel in south San Diego Bay on 15 September, and Meryl Faulkner reported that Project Wildlife has received at least three Storm-Petrels picked up at inland locations.
One or two Reddish Egrets wintering around San Diego are customary, but the species is far less frequent in the north county lagoons. Many observers saw the immature at San Elijo Lagoon 11-30 September.
The immature Wood Stork found at Los Peñasquitos Lagoon on 8 July, the first to arrive in San Diego County in several years, was last reported by Jim Zimmer on 15 September.
The male Greater Scaup noted by Gjon Hazard at the Chula Vista Marina on 15 September must have spent the summer since the date was a month early for arrival of winter visitors. The one Pete Ginsburg found at O'Neill Lake on 30 October and the White-winged Scoter Ed Wallace found at Chula Vista on 28 October were at the time expected for arrival of these northern ducks. The White-winged Scoter was common in San Diego Bay 40 years ago but is now very rare.
The Broad-winged Hawk can be expected in San Diego County only on Point Loma and only in a narrow window of time in early October. This year's reports, from Guy McCaskie on 1 October and Jim Sams on 11 October, typify this pattern. The Zone-tailed Hawk had returned to its usual haunt in the Wild Animal Park by 20 October, when Richard Hodges reported one. More surprising was the one Arnold Young reported from La Mesa on 22 August. Another returnee, for at least its second winter, was Christine Rideout's Peregrine Falcon at the Escondido Center for the Performing Arts. The female Peregrine released from captivity that inaugurated the species' recolonization of the county died at the age of at least 17. Mark Polinsky found her helpless in the water of San Diego Bay near her nest on the bridge, and Dan Brimm's efforts to save her failed. If her mate attracts a new female to the bridge's nest site, the county's population of four pairs will consist entirely of Peregrines of wild origin.
Rare shorebirds reported this fall included two Semipalmated Sandpipers at San Elijo Lagoon 10-21 August by Gjon Hazard, four Stilt Sandpipers there on 30 September by Ed Hall, a Ruff in the south San Diego Bay salt works on 13 October by Monica Alfaro, and a Pacific Golden Plover at the Tijuana River mouth from 24 August to 7 September by Robert Patton. Overshadowing these, though was the Bar-tailed Godwit, only the third for San Diego County, found in the San Diego River flood-control channel 4 September by John Martin.
The 11 Common Murres Pete Ginsburg saw from La Jolla on 10 October were both early arrivals and a high number for this species whose numbers in California over the past 20 years have crashed.
The Black Swift is a very rare migrant through San Diego County and most records are in spring, making the two seen by Richard Webster at Cabrillo National Monument on 4 October doubly notable. Richard's Least Flycatcher at Fort Rosecrans Cemetery on 6 October was only one of this rare vagrant found this fall. Jerry White, Pete Ginsburg, and others discovered an Eastern Phoebe, an occasional fall and winter visitor, at Whelan Lake on 19 October.
Brian Foster discovered an Eastern Kingbird in the Tijuana River Valley on 9 September; this species doesn't reach San Diego County every year. The Tropical Kingbird is more frequent, and probably at least three were on Point Loma between 24 September and 4 October. Lori Hargrove watched a Cooper's Hawk kill and eat one of them, removing at least one vagrant from the gene pool.
Vagrant vireos showing up on Point Loma included Gjon Hazard's Blue-headed 29 September-2 October and Sue Smith's Philadelphia 29-30 September. Pete Ginsburg found a Red-eyed in San Marcos 24 September.
Paul Jorgensen's flock of 15 Clark's Nutcrackers on Cuyamaca Peak 16 October was the county's largest since the invasion of 1935. It was followed by two in Pine Valley on 17 October and one there 19 October (Mike Mathos). Similarly, Royce Riggan's three Townsend's Solitaires at Mataguay Boy Scout Camp on 8 October and Paul's five on Cuyamaca Peak on 16 October are large numbers for this rare winter visitor.
Reports of the Red-breasted Nuthatch were scattered from Cabrillo National Monument to Nolina Wash in the Anza-Borrego Desert, where Dave Seals and Shannon Peters had one in a yucca on 15 October. The White-breasted Nuthatch Richard Webster discovered in Fort Rosecrans Cemetery on 4 October remained into November and was giving the call typical of the Rocky Mountain subspecies nelsoni, never before reported in San Diego County. This bird, though, helps narrow our focus on the origin of the invaders reaching us this year.
A couple of Golden-crowned Kinglets on Point Loma might have been expected even in a noninvasion year. But the numbers of Pine Siskins have attracted the attention even of the general public, prompting calls asking me "what are these birds overwhelming the Lesser Goldfinches at my feeders?" The species that virtually defines winter invasions is the Red Crossbill. Mary Beth Stowe had one at Observatory Campground on Palomar Mountain on 26 October.
With agriculture in the Tijuana River Valley almost at its end, records of longspurs in San Diego County have almost ceased. John Martin found a female or immature Chestnut-collared on the sod farm along Dairy Mart Road 17 October; Elizabeth Copper found a male there 19 October.
As always, vagrant warblers from farther east surfaced this fall. This year's finds included at least two Virginia's, one Chestnut-sided (Fort Rosecrans, 29 September, Sue Smith), about 6 Magnolias, two Black-throated Blues, two Black-throated Greens (including one at Guajome Lake, presumably returning for another winter), three Blackburnians, one Prairie (O'Neill Lake, 27 September, Pete Ginsburg), one Palm, one Blackpoll, four Black-and-whites, seven American Redstarts, two Ovenbirds, and one Painted Redstart (Fort Rosecrans, 14 October, Tim Plunkett). The Canada Warbler is typically one of the less frequent species, not found in the county every year, but this fall yielded four, two at Cabrillo National Monument 20-22 September (Dennis Wysong), one at Fort Rosecrans 10 October (Tim Plunkett), and one in Cardiff (Gjon Hazard).
All the tanagers known from California showed up in San Diego County this fall. Besides the Western, common in migration, vagrants of the Scarlet (5 October, Richard Webster), Hepatic (26 September, Pete Ginsburg), and Summer (at least three, 7-11 October, Joe Worley) reached Point Loma. The summering Summer Tanagers remained at Old Mission Dam at least to 4 September (Margaret McIntosh) and at Scissors Crossing to 8 September (two families; Paul Jorgensen). A few rare orioles showed up too, an Orchard at Fort Rosecrans 9 October (Richard Webster) and Baltimores there 1 October (Guy McCaskie) and at Lake O'Neill 29 September (Pete Ginsburg).
A new escapee to be on the watch for is the Orange Bishop, illustrated in the latest National Geographic field guide and proliferating in Los Angeles, where it feeds on an exotic grass growing in drainage channels. One was seen repeatedly this fall at Famosa Slough.
Thanks as always to Mike Evans for maintaining and distributing the spreadsheet of rare bird reports.