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

WRENDERINGS
Notable Observations
Spring 1998

Even though this winter has been a relatively quiet one, especially in comparison to last year with its invasions of crossbills, nutcrackers, Red-breasted Nuthatches, etc., there have been so many notable observations that this column can touch only on the highlights. And with most observers still to report for the winter or my lacking adequate details on some observations, this report is doubtless far from thorough. See the column on the blockbuster weekends for notable observations during those events. Fuller reports on the Christmas Bird Counts have been sent by many of the compilers to the count participants.

Yet another new nesting site for the ever-expanding Western and Clark's Grebes is San Dieguito Reservoir in K8, where young chicks were seen in December and January by Jim Determan, Kathy Aldern, and Maryanne Bache. Winter nesting of grebes is apparently normal, having been reported from Sweetwater Reservoir back to the 1960s.

Following the appearance of two sick Brown Boobies in San Diego Bay in October and November, Peter Longsdale found a freely flying bird at La Jolla (P7) in February, and Royce Riggan relocated it two days later at Point Loma (S7). Is the appearance of this tropical ocean bird a by-product of El Niño?

The single Reddish Egret and Tricolored Heron in the Tijuana River estuary this winter are expected, but an adult Yellow-crowned Night Heron seen by Taryn Johnson in L10, La Jolla Valley, during the Rancho Santa Fe CBC was a surprise. Could it be the same individual that has been attending the Black-crowned Night Heron colony at Scripps Institution in La Jolla for the past 15 years?

Least Bitterns are rare, especially in winter, but easily overlooked while hidden in dense marshes unless one is familiar with their rail-like call. This winter reports have been from Calaveras Lake in H7 by Karen Messer and Bob Turner and at Miramar Reservoir in N10 by Mary Beth Stowe.

A White-faced Ibis found at Lake Henshaw, G17, during the CBC by Jim Zimmer and Ed Hall was at an unaccustomed high-elevation location.

The Wood Stork that has taken up residence in the Wild Animal Park, J12, was seen (from the monorail) during the Escondido CBC by Liz Hutson and Dennis Huckaby. It is very likely the only Wood Stork in California in winter.

Though northern land birds are few this winter, an exceptional variety of northern ducks has reached San Diego this winter. Eurasian Wigeons have been unusually widespread, reported in the San Dieguito River estuary (M7), San Diego River flood-control channel and Famosa Slough (R8), the Sweetwater River channel (T10), and the Tijuana River estuary (V10).

Two Blue-winged Teal found at the Borrego Springs sewage ponds (H25) by Robin Halford on the Borrego Springs CBC were in an area where even the common ducks are rare.

The male Tufted Duck at Famosa Slough (R8), found by tour leader Barry Zimmer, was only the second ever in San Diego County.

The Oldsquaw is a rare if nearly annual visitor to San Diego Bay, this year with one at Shelter Island (S8) found by Doug Aguillard and two at the Chula Vista SDG&E plant found by Robert Patton. Robert's big surprise at the power plant outflow, though, was a female Harlequin Duck, the first in San Diego County since 1983.

The Black and White-winged Scoters, whose winter ranges have largely retracted to the north of San Diego County, both appeared at the Imperial Beach pier (V10); Pete Ginsburg found another White-winged in the Oceanside harbor (H5).

The Common Goldeneye found at Famosa Slough (R8) by Barbara Peugh seems to be the only one reported in the county so far this winter.

Hooded Mergansers were exceptionally widespread and numerous, with maxima of 13 seen by Jim Zimmer along San Marcos Creek in I8 and 20 seen by Marjorie Hastings at Santee Lakes (O12).

Yet another possible nesting of the Osprey in San Diego County is suggested by Mark Jorgensen's observation of one carrying a stick in Torrey Pines State Reserve in N7.

Besides a typical 5 Bald Eagles wintering at Lake Henshaw, Ed Hall noted one near Julian in K20.

At least one Harris' Hawk, left over from the incursion in 1994, continues to persist in the Borrego Valley, with sightings by Paulette Ache and Bob Thériault in F24 and G24.

A few Zone-tailed Hawks are now seen in the county each winter; this year's observations have been by Claude Edwards near Rainbow (C9) and Guajome Park (G7) and Ed Hall near the Wild Animal Park (J12).

Will the two Peregrine Falcons discovered at the El Cajon courthouse (Q13) by Tony Mercieca make the fourth nesting pair in San Diego County?

The endangered Clapper Rail has colonized a new site, along the Sweetwater River near the Plaza Bonita shopping center (T11), where noted by Ron and Linda Johnson on the San Diego CBC.

The Black Oystercatcher, though resident on Los Coronados Islands, shows up only irregularly on San Diego's rocky shores; Royce Riggan found one at La Jolla (P7). As usual, winter storms blew Red Phalaropes to shore; one got a bit inland near Guajome Lake (G7), where found dead by Jeff Manning.

The famous Belcher's Gull, seen regularly at the Tijuana River mouth (V10) since early August, finally disappeared after mid-January.

The Common Ground Dove is a widespread if uncommon and inconspicuous resident of orchards in northwestern San Diego County, but Ken Weaver's observation of 38 in one gourd field in De Luz (B6) is exceptional.

The winter status of the Poor-will remains nebulous; do most migrate or hibernate for the winter? The species was detected at an unusual number of sites this winter, in squares K9 by Robert Patton, J14 by Dick Barber and Clark Mahrdt, and K12 and L12 by John McColm.

Most Vaux's Swifts winter far to the south of us, but a few appear irregularly at this season in the Oceanside area. But this winter's only report so far is of one at at the east end of Lake Hodges (K11) by Santa Barbaran Brad Schram.

Sometimes years pass without a Broad-billed Hummingbird straying west to California, so Mary Beth Stowe's discovery of one at the east end of San Elijo Lagoon (L7) was one of the winter's least expected observations.

Despite the dearth of northern forest birds dispersing south to southern California, the Lake Henshaw CBC, still got a Williamson's Sapsucker, with a sighting of a male near Wynola (J19) by Julie Alpert.

Besides the one near Dulzura found on the blockbuster weekend, there has been only one other report so far this winter of the Western Flycatcher, rare at this season: in Quail Gardens (K7) by Rita Campbell and C. C. Gorman.

Away from a couple regular sites in the Anza-Borrego Desert, the Vermilion Flycatcher is very rare, making observations in the Wild Animal Park (J12) by Ken Weaver and at La Costa by Mona Baumgartel noteworthy. Mona saw the latter from a golf cart, thanks to the cooperation of the La Costa Golf Course.

Usually, the Ash-throated Flycatcher is entirely absent in winter from coastal San Diego County, so two sightings, of one in Vista (I8) by Vesta Dineen, Allen Craft, and Caryl Parrish and another in North City West (M8) by Phil Unitt were unexpected. Wintering Ash-throated Flycatchers are more likely but still rare in the Anza-Borrego Desert, so the one found in Borrego Springs (F24) on the CBC by Oz Osborn fits this pattern. But the four found in Canyon sin Nombre (P29) in the southern Anza-Borrego Desert by Dan Langhoff are unprecedented -- and possibly another reflection of the favorable winter rains.

The Tropical Kingbird reaches San Diego County every fall but rarely occurs in winter, making the two found in Imperial Beach (V10) by Claude Edwards notable. But the discovery in Fullerton of a Couch's Kingbird, a species of southern Texas and eastern Mexico no one expected ever to reach California, plus two Western Kingbirds, almost unprecedented in California in winter, made headlines in Orange County.

Both the Cassin's and Plumbeous Vireos, recently reassessed as species rather than subspecies of the Solitary Vireo, occur as rare but regular winter visitors in San Diego County, typically in riparian woodland. Guy McCaskie found one of each near the Dairy Mart ponds in the Tijuana River valley (V11) during the San Diego CBC. Phil Unitt and Jack Schlotte found another Plumbeous in the San Pasqual Valley (J12) during the Escondido CBC, and visitor Doug Shaw reported one from Guajome Park (G7).

Far less expected was a Warbling Vireo found on the San Diego CBC at North Island Naval Air Station (S8) by Robert Patton. This species, though still fairly common in migration, is extremely rare in early winter and probably never stays or survives through the whole winter.

Another of the rare exceptions to the lack this winter of northern forest birds were the two Townsend's Solitaires seen on Volcan Mt. (I20) by Bill Haas and Robert Patton.

The only Sage Thrasher reported this winter other than the one on the Anza-Borrego blockbuster was one at Agua Caliente County Park (M26) by Ed Hall.

Ed Post discovered a San Diego Cactus Wren at a new site at the northeast base of Cowles Mountain in P12.

A few wintering Violet-green Swallows in northwestern San Diego County are expected, so observations of one at Windmill Lake (G6) by Phil Unitt, 14 at San Elijo Lagoon (L7) by Ingri Quon, and two at the San Dieguito River estuary by Freeman Hall are fairly typical. But wintering Barn Swallows are far less expected, and three reports in a winter, of three at Batiquitos Lagoon (J7) by Freeman Hall, one at the San Dieguito River estuary (M7) by Mary Beth Stowe, and two at Sweetwater Reservoir (S12) by Pete Famolaro, are probably unprecedented.

The always irregular Lawrence's Goldfinch has been unusually numerous and widespread this winter, with a maximum report so far of 150 northeast of Lake Henshaw on the CBC by Geoff Rogers and Don Adams.

The Swamp Sparrow is a fairly regular rare winter visitor but the only report so far is of one in the San Dieguito Valley (M8) on the Rancho Santa Fe CBC by Phil Unitt and Jack Schlotte. Likewise, only one White-throated Sparrow has been reported, besides the one on the Pauma Valley blockbuster: one at Agua Caliente County Park (M26) by Ed Hall.

The Grasshopper Sparrow, rare or difficult to detect in winter, has been reported at five sites: in the San Luis Rey River valley near Interstate 15 (E9) by Kurt Campbell, along Questhaven Road (J9) by Jim Zimmer, in Los Penasquitos Canyon (N8) by Alice DeBolt, in Alpine (P17) by Claude Edwards, and in Johnson Canyon, Otay Mesa (V13), by Phil Unitt.

Though it winters regularly not far south and east of us in Baja California and Arizona, the Lark Bunting is a rarity in San Diego County. Rich and Susan Breisch saw one with a flock of Horned Larks near the coast of Camp Pendleton in square E3.

Sixteen species of warblers have been reported in San Diego County this winter, not a bad figure given that only four are even fairly common. Perhaps the most remarkable warbler observation was Jim Zimmer's Prairie in Carrizo Gorge near Indian Hill (R28) -- there's some justice in one of our most dedicated atlas participants covering one of the most difficult and remote squares finding the rarest warbler.

Three species of orioles in San Diego County this winter are notable, given that once none were known to winter here. The Bullock's is annual in small numbers in the coastal lowland. On the desert side, Scott's is now known as a regular, localized winter visitor, with observations in the Borrego Valley (G24) by Paulette Ache and Claude Edwards and at Agua Caliente County Park (M26) by Ed Hall. The species is also regular in prickly pear thickets in the San Pasqual Valley (J12), where found this year by Jim Coatsworth and Bill McCausland, and at hummingbird feeders at Warner Springs (F19), where found by Mike Klein. But the rarest oriole found this winter was the Hooded at Eucalyptus Park in Chula Vista by Marjorie and Don Hastings. With many migratory species, their abundance in summer is no guide to their likelihood in winter.

--Philip Unitt

birdatlas@sdnhm.org

Spring 1998 Wrenderings | Wrenderings Archive | Bird Atlas Introduction