San Diego Natural History Museum--Your Nature Connection[San Diego County Bird Atlas Project]

WRENDERINGS
Notable Observations
Spring 2002

Unfortunately, deepening drought depressed numbers of many species in the final winter of our data recording for the atlas, especially in the more remote desert and chaparral squares that we needed to hit hardest this winter to reach our coverage goals. In contrast to last year, we had few irregular montane invaders, though Townsend's Solitaires bucked the trend. Still, a lot of interesting birds turned up, especially on the Christmas bird counts. Thanks very much to Robert Patton, Ken Weaver, Bob Thériault, and Dennis Wysong for providing the results of the Rancho Santa Fe, Escondido, Anza-Borrego, and Oceanside counts to us, and thanks as always to Mike Evans for providing the spreadsheet of reports to the San Diego Field Ornithologists' rare bird hotline (619-688-2473).

With only three previous well-supported records, the Red-necked Grebe is one of San Diego County's rarest birds, here far south of its usual winter range. Thus the one Dave Povey found just outside the mouth of San Diego Bay on 15 December was one of the most remarkable discoveries on the San Diego Christmas bird count. Stan Walens followed by reporting another on the ocean off Los Peñasquitos Lagoon (N7) on 23 December for the Rancho Santa Fe count. The Horned Grebe is very rare inland but has shown up in small numbers at Miramar, El Capitan, and Loveland reservoirs. The 20 Jim Wilson counted at Loveland (Q16) on 12 January are the largest number reported inland in San Diego County yet.

The subadult Masked Booby discovered by Alaskan visitor Milo Burcham at La Jolla (P7) on 30 December was undoubtedly the most sensational discovery of the winter. It remained through 10 January, to be seen by many. The Masked Booby has been conclusively identified in California only about 15 times previously, on all but three occasions far out to sea and only once far off San Diego. A little broader view, though, suggests almost an invasion of boobies. Another Masked was picked up injured in Orange County, and yet another was seen around Los Coronados Islands, along with two Brown and one Blue-footed. On 3 January, while photographing the Masked Booby, Tony Mercieca spotted a Magnificent Frigatebird cruising overhead, capturing it too on film. A few frigatebirds reach San Diego each summer but are very rare in winter.

White Pelicans were far more widespread this winter than in the past. They were recorded in 27 squares versus 17 in the past four winters combined. They showed up on lakes and ponds scattered throughout the county and were seen cruising overland far from water--most notably near Lower Willows in Coyote Creek Canyon (D23), where Phil Pryde estimated 100 on 16 December for the Anza-Borrego Christmas bird count.

With the recent disturbance of the night heron colony at the Scripps Institution of Oceanography, the fate of the colony, along with the Yellow-crowned Night Heron that has joined it for the past 20 years, became an open question. Christine Nyhan may have found a clue with her observation of the Yellow-crowned at the La Jolla Beach and Tennis Club (P7) on 6 December.

Illustration of Harlequin Duck head

Dennis Parker reported the first Tundra or Whistling Swan in San Diego County in several years, with one flying north from the naval amphibious base (T9) in San Diego Bay on 16 February. The White-fronted Goose is now a rare winter visitor along the coast; Mark Billings found one in the Kendall-Frost marsh area of Mission Bay (Q8), 29 December-7 January. Also very likely White-fronted were a flock of geese flying north at 11:45 PM on 22 January, tape-recorded by Joe Barth. Other records suggest the White-fronted is migrating in January, earlier than other geese, but we have sent the tape to Kimball Garrett for evaluation. The Greater Scaup is rarely critically identified in San Diego County, the southern extreme of its winter range. Joe Worley reported one from Santee Lakes (P12) on 4 December, Brennan Mulrooney five from the San Diego River flood-control channel (R8) on 12 February. Another rare duck from the north, a male Harlequin Duck, spent the winter in the northeast corner of Mission Bay (R8). The Common Goldeneye is regular in San Diego County only in south San Diego Bay, making this winter's two reports elsewhere notable. Bill McCausland and Penny Hernandez had one on a small pond in SE Escondido (J11) on 29 December, the first ever found on an Escondido Christmas bird count, and George Chaniot reported four from Sweetwater Reservoir (S12) on 17 January.

A single Harris' Hawk continued to be seen sporadically through the winter in S Borrego Springs (G24), but the one Betty Siegel and Oz Osborn spotted near Warner Springs on 17 December was by far the least expected species found on the Lake Henshaw Christmas bird count. In second place for best bird of the Henshaw count was the Zone-tailed Hawk seen near Mesa Grande (H16) by Bob Sanger and Brian Loly. The only other Zone-tail reported this winter was the one now regular at Oak Hill Cemetery (I12) on the east edge of Escondido.

The Pacific Golden Plover at the Tijuana River mouth (V10) returned to spend a fourth winter, and another showed up in the San Dieguito River estuary (M7), reported first on 3 January by Tom Benson and Neil Fergusson and seen as late as 30 January by Marjorie Hastings. Though regular in small numbers on Los Coronados Islands, the American Oystercatcher is one of the rarest birds of San Diego County, with only four individuals known previously, and at least one of these was a hybrid with the Black Oystercatcher (the two species hybridize to some degree in northern Baja California). Brennan Mulrooney reported one from Zuñiga Jetty at the mouth of San Diego Bay (S8) on 27 January. The winter's most notable gull was the first-year Glaucous found by Don Adams at Quivira Basin in Mission Bay (R7) on 4 February. Of the many rare birds found on the San Diego Christmas bird count on 15 December, one of the rarest was the Marbled Murrelet seen by Dave Povey from his boat, just beyond the breakers at Coronado. This makes only the fourth county record of this vagrant from the Pacific Northwest, last recorded in 1981.

The Spotted Owl is practically unknown away from its breeding habitat, so one reported by Chris Otahal from a palm grove near Maidenhair Falls in Hellhole Canyon (G23) was completely unexpected. Vaux's Swift is a regular winter visitor around Oceanside, the only site in the U.S. where this species does winter regularly, so Jerry Smith's 12 at Guajome Lake (G6) 13 December and Robert Patton and Shauna Wolf's 4 at Windmill Lake (G6) 22 December were not a surprise. But winter records elsewhere, like George Chaniot's 50 at Sweetwater Reservoir 16-17 January, are exceptional.

Lewis' Woodpeckers went reported less than usual this winter. The best spot was around Pine Hills Road and Highway 79 (K19), where Ann & Tom Keenan and Mary Beth Stowe had up to five, 4-6 February. When Lori Hargrove, Jim Determan, and Bob Sanger made a difficult backpacking expedition to cover the upper elevations of square C21 they were rewarded by a male Williamson's Sapsucker in a small grove of Coulter Pines at 4500 feet elevation in Sheep Canyon. The Ladder-backed Woodpecker is so resident in its range that dispersal even a short distance out of it is notable. On 26 January Bob Sanger and Kathy Williams found one on the south side of Oak Grove Valley in square D16, about 2 miles from semidesert scrub on the north side of the valley where the species is resident. Two Hairy Woodpeckers wandered far out their normal ranges, one to Felicita Park (J10), where Robert Patton found one for the Rancho Santa Fe Christmas bird count on 23 December, one to the sparse pinyons in the Santa Rosa Mountains (D27), where Lori Hargrove found one on 9 January. Joe Barth found a Yellow-shafted Flicker, rarely seen in San Diego County in pure form, in Thing Valley (Q24) on 9 December.

Given that San Diego County has only three common species of wintering flycatchers (the Black and Say's Phoebes and Cassin's Kingbird), it is remarkable that 11 species total were recorded here this winter. Guy McCaskie relocated the Least Flycatcher that had wintered previously at the Dairy Mart pond (V11) on 9 December. Claude Edwards found a Gray Flycatcher at Warner Springs (F19) on 9 December, Ed Hall and Jim Zimmer found another for the Escondido Christmas bird count near the upper end of Lake Hodges (K11) on 29 December, and Richard Webster found a third in Greenwood Cemetery (S10) 18 December-21 January. Also for the Escondido count, Bill Haas found a Western Flycatcher in the San Pasqual Valley (J12); Gus Hollenbeck located another in the Golden Hill section of Balboa Park (S9) 16 December-3 February. There were two Vermilion Flycatchers around Borrego Springs (G24 and G25; Don Waber and Herb Stone), plus two on the coastal side, one at Lindo Lake (P14, from at least 2 December) and Lower Otay Lake (U14, Oz Osborn). The Dusky-capped Flycatcher discovered for the San Diego Christmas bird count on 15 December by Jim Zimmer was only the fourth for San Diego County. In the subsequent weeks many people went to see it, finding many other rare birds in the process--a classic example of the "Patagonia picnic table effect." Two Ash-throated Flycatchers were reported too, one by Guy McCaskie for the San Diego count at the Diary Mart pond (V11), the other by Jim Wilson in the Anza-Borrego Desert near Borrego Sink and Hills of the Moon washes (G27). The Tropical Kingbird found by Claude Edwards at Rohr Park (T12) on 1 December stayed at least to 14 January. Much more notable was the Western Kingbird discovered by Guy McCaskie at Greenwood Cemetery on 16 December and remaining at least to 7 February--it made only the fourth well--supported identification of this species in San Diego County in winter.

The vireos gave the flycatchers a run for their money. Besides the resident Hutton's, there were three reports each of Cassin's and Plumbeous, about average. Jim Determan found a Warbling Vireo at Buena Vista Lagoon (H5) on 22 December, perhaps the best bird for the Oceanside Christmas bird count. The Bell's Vireo Richard Webster found for the San Diego count in Coronado (S9) was the first found wintering in San Diego County since 1990, but it was upstaged by his Philadelphia also in Coronado that day, the first recorded in winter in San Diego County and only the fourth in winter for all of California.

Illustration of Townsend's Solitaire

In spite of the general lack of montane invaders this year, we still had one report of a Winter Wren (in Marion Canyon, D12, on 18 January, Ken Weaver), four reports of Golden-crowned Kinglets, two of Red-breasted Nuthatches, two of Cassin's Finches, six of Varied Thrushes and at least 17 of Townsend's Solitaires. The latter ranged up to the six individuals observed by Ken Weaver along Agua Caliente Creek at the west base of Hot Springs Mt. (E20) on 26 January and the seven observed by Shauna Wolf and Robert Patton on Volcan Mt. (I20) for the Lake Henshaw count on 17 December. On the same long, difficult hike when he saw all the solitaires, Ken Weaver encountered a Sage Thrasher in the same area, quite out of place around 3800 feet elevation. Another oddity was the two White-breasted Nuthatches in Greenwood Cemetery, recorded on the San Diego count for only the third time in over 20 years. Similarly, Geoff Rogers' Oak Titmouse in the Tijuana R. valley (W10) on 1 December represented dispersal toward the coast rarely seen in that species.

Barn Swallows continued their recent trend toward increasing in winter, with up to 12 at Whelan Lake (G6) on the Oceanside count (Don Adams, Geoff Rogers, Jim Coatsworth) and 15 at San Elijo Lagoon on the Rancho Santa Fe count (Robert Patton). Brennan Mulrooney monopolized reports of unusual sparrows with one of the red subspecies zaboria of the Fox at Santee Lakes (O12) on 12 February, one Swamp at Lindo Lake (P14) from 17 January to 9 February, and one Clay-colored at Oak Hill Cemetery (I12) on 16 February. Three White-throated Sparrows and four Green-tailed Towhees were typical numbers for these rare winter visitors.

Rare but annual wintering warblers included three Nashvilles, seven Yellows, five Black-throated Grays, three Palms, six Black-and-whites, four American Redstarts, one Northern Waterthrush, and five Wilson's. It seems that the Black-throated Green is now falling into this category too. Besides the one in Doug Aguillard's yard in National City (T11), returning for its fifth winter, one showed up for the San Diego count in Elizabeth Copper's yard in Coronado (S9), and Jim Determan, Joe Barth, and I found another for the Oceanside count near Buena Vista Lagoon (H5). The most notable warblers were the Hooded Robert Patton found for the San Diego count along the border between North Island Naval Air Station and residential Coronado (S8), the Chestnut-sided Matt Sadowski found in the Seaport Village area of the San Diego waterfront (S9) on 1 February, and the Grace's, originally found in Fort Rosecrans Cemetery (S7) on 30 September still there on 16 February. The last made only the third winter record of Grace's Warbler for San Diego County.

It was an exceptional winter for Summer Tanagers with 12 reported--more than of the usually more numerous Western Tanager. The Rose-breasted Grosbeak is more frequent in winter than the Black-headed: Ginger Johnson and Mary Beth Stowe found three Rose-breasteds on the grounds of the San Diego Zoo (R9) for the San Diego count, while Jim Determan found another in Borrego Palm Canyon (F23) on 6 December. Much rarer still in winter is the Blue Grosbeak: Guy McCaskie saw one in the Tijuana R. valley (V11) on 9 December, only the sixth winter record for San Diego County.

Illustration of Yellow-headed Blackbird

Leslie & Mark Polinsky found the winter's only Yellow-headed Blackbird, in the Tijuana R. valley (V10) for the San Diego count. Six reports of Bullock's Oriole and three of the Baltimore Oriole near the coast were less surprising than three of the Hooded, normally far less frequent: Ginger Johnson had one in the San Diego Zoo (R9), Stan Walens another in the San Diego Country Club in Chula Vista (U11) for the San Diego count, and Gjon Hazard found another in Greenwood Cemetery (S10) 2 February. Both the Hooded and Orchard are about equally likely in the winter and very easily confused at that season, when we see immature birds almost exclusively. Brennan Mulrooney found an Orchard in Greenwood Cemetery 11-19 January.

--Philip Unitt

birdatlas@sdnhm.org

Spring 2002 Wrenderings | Wrenderings Archive | Bird Atlas Introduction