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

WRENDERINGS
The quarterly newsletter for Bird Atlas volunteers
Fall 2000

Osprey
Osprey

So many notable observations were made over the past three months that I have to confine this column to confirmed and possible breeding species and just the most exceptional vagrants. See "The Blockbuster to End All Blockbusters" in this issue for observations made during our Lake Henshaw event. Thanks again to Mike Evans for forwarding the spreadsheets of reports to the rare bird hotline (619-688-2473).

Eared Grebes nested in San Diego County for only the second time in the past four years. Bill Haas noted three young with their parents at the Ramona Water District's pond along Rangeland Rd. on 15 June (K13).

The Great and Snowy Egrets continue to start new colonies. The two new sites for the Great are at Lindo Lake (P14), where Mary Beth Stowe found one building among the other herons' nests on 18 May, and El Capitan Reservoir (O16), where Dave Seals and Joe Barth found a nest with a nestling in a tree in which a Great Blue Heron had nested previously. Three new sites for the Snowy are Lindo Lake, where Mary Beth also found them building on 18 May (with the Great Blue and Black-crowned Night, this colony now has four species of herons); Guajome Lake (G7), where Ken Weaver noted two nests with nestlings on 5 July; and the pond just south of the San Luis Rey River and east of Interstate 15 (E9), where on 5 June Dennis & Carol Wysong found the adults feeding two fledglings.

The Wysongs also discovered a new site for the White-faced Ibis there, with at least two nests. This is only the second colony of the ibis currently active in San Diego County. The marsh at Guajome Lake having grown too dense to be surveyed by boat, Ken Weaver scoped it from the north shore on the evening of 5 July, counting 31 ibises, including a nestling being fed by an adult, finally confirming continuing nesting at the other known colony and putting to bed one of the "last holdouts" listed in the last Wrenderings.

The Wood Stork continues to decline as a postbreeding visitor to the Salton Sea, so it is amazing when one reaches the coast nowadays. One was at Los Peñasquitos Lagoon 8-23 July. Sightings of ducks rare in summer were Pete Ginsburg's of an American Wigeon and Blue-winged Teal at O'Neill Lake (E6) 21 May, James Barr's of a Canvasback on Cuyamaca Lake (M20) 8 June, and Richard & Susan Breisch's of a Ring-necked Duck at the NE corner of Lake Morena 1-2 July.

Both of San Diego County's known pairs of nesting Ospreys fledged young successfully again this year, from North Island Naval Air Station (S9) and Scripps Ranch High School (N10). Richard & Susan Breisch had a Zone-tailed Hawk near Morena Village (T22) on 7 May. The Zone-tailed remains a holdout on confirmed breeding, but these accumulating sightings during the breeding season suggest it's likely.

The Common Snipe is not known to nest as far south as San Diego County, and there are only a couple of previous reports during the breeding season. Yet Jim Wilson found them consistently at Tule Lake (T27), with a maximum of three on 21 June. The Arctic Tern is almost never seen on shore and is very rare in spring, so Dennis Parker's in the tern colony at the Santa Margarita River mouth (G4) on 4 June was doubly exceptional. Tom Dorman saw three Black Skimmers at Upper Otay Lake (T13) on 19 July, to my knowledge the first report of this species inland in San Diego County.

Mel Gabel discovered two Inca Doves at the Roadrunner Club in Borrego Springs (F24) 20-24 June, another step toward this species' colonizing San Diego County. The Flammulated Owl has been noted rarely on both Palomar and Hot Springs mountains in the past, but Ken Weaver's and Clark Mahrdt's records from Palomar (D15) on 19 July and Hot Springs (E20) on 2 and 3 July are the only ones in the past four years. Ken found another possible new nesting species near High Point on Palomar (D15) with three Calliope Hummingbirds on 20 May and 12 July. There are only two previous summer records for San Diego County.

The late lingering of Lewis' Woodpeckers reached its culmination with the latest spring record ever for San Diego County: Gail Wynn picked up one that had got trapped in the Salvation Army shed in Descanso (P20) on 1 June. The Red-breasted Sapsucker has long been known as a breeding species on Palomar Mountain, but our atlas effort has revealed that it is also a regular if rare nesting species in the Cuyamaca Mts. This year, Paul Jorgensen found a nest near the state park headquarters (N21) on 20 June, and Joe Barth found fledglings at only 3500 feet elevation just north of Descanso (O19) on 4 July. The latter marks the southernmost Red-breasted Sapsucker nesting ever recorded.

Scissor-tailed Flycatcher
Scissor-tailed Flycatcher

The Scissor-tailed Flycatcher found by Jim Zimmer near the NE corner of Mission Bay (Q8) 22-27 May stayed long enough to delight many observers.

Pete Famolaro discovered a singing White-eyed Vireo along the Sweetwater River between Sweetwater Reservoir and Highway 94, 5-15 July, only the fifth ever in San Diego County. Because the Warbling Vireo is common as a migrant but so rare as a breeding species, actual confirmations are critical to understanding its distribution. Ken Weaver had fledglings near De Luz (B6) on 22 July, and Jim Determan and I had a pair building a nest in Castro Canyon (C12) on 13 May. While the vireos were away from the nest, we saw a female cowbird approach and sit in the nest--parasitism caught red-handed! Cowbird parasitism has presumably been the primary factor in the near extirpation of the Warbling Vireo from San Diego County, and the Warbling has been much slower to benefit from cowbird trapping than the Bell's.

The Western Bluebird is betraying hints of being an incipient urban adapter, but it showed adaptability in an unexpected direction when Paul Jorgensen found three fledglings with their mother at Borrego Springs High School in the 118°F heat on 20 July. Another of the "last holdouts," Swainson's Thrush, fell this summer when Jeff Wells found a nest (in Arundo donax!) along the Santa Margarita River in Camp Pendleton and Pete Ginsburg found two feeding young nearby (E5) on 28 June. We also conquered the Hermit Thrush this year, the first confirmed breeding of this species in San Diego County. Ann & Tom Keenan found a fledgling on Volcan Mt. (I20) on 28 June, and Richard Webster saw an adult feeding young on Middle Peak (M20) on 2 July. Paul Jorgensen monitored another territory along Azalea Creek on Palomar Mt. (D14/E14).

David Seay's Gray Catbird in Bow Willow Canyon (P27) on 31 May and Pete Ginsburg's along the Santa Margarita River near the Camp Pendleton airport on 28 June were only the second and third in San Diego County in spring or summer. Dennis Parker encountered a Mountain Chickadee at Felicita Park (J10) on 22 May. Chickadees are regular at low elevations in northwestern San Diego County in winter but there were no records from this area during the breeding season. The Golden-crowned Kinglet has been known as a summering species near the tops of Hot Springs and Cuyamaca mountains since the mid 1980s but there hadn't been any reports from Palomar until this year. Joe Barth had one there (E14) on 15 July.

Purple Finches continue to summer at low elevations in northwestern San Diego County. Ken Weaver had a maximum of 10 around De Luz (B6) 20 June, and Jim Determan found a nest, the first low-elevation confirmation, at 1800 feet in the Lodge Ranch (C12) on 30 April.

Victory over two more "last holdouts": Richard Webster saw two Fox Sparrows feeding young on Middle Peak on 2 July, and Joe Barth saw an adult feeding a fledgling on nearby Cuyamaca Peak on 13 July. I believe these are the first actual confirmations of Fox Sparrow breeding in San Diego County. Similarly, on Cuyamaca Peak Gjon Hazard saw a Yellow-rumped Warbler feeding a fledgling on 18 June, Joe Barth on 13 July. Ken Weaver had a Nashville Warbler near Palomar Mountain's High Point on 12 July, making the third summer a Nashville has occurred on Palomar. The spring's most outstanding vagrant warblers were Prothonotaries at Quail Gardens (K7) on 1 May (C. C. Gorman, Rita & Alan Campbell) and Point Loma 20-25 May (Pete Ginsburg).

In addition to the Summer Tanagers on the desert side, Ken Weaver found two pairs carrying insects on the Santa Margarita River above Sandia Creek Dr. (C8) 1-8 August, extending the species' nesting to the coastal slope. He also found a single male at Wilderness Gardens (D12) 13-21 May, Mary Beth Stowe another at Old Mission Dam (P11) 8-10 August. Despite the Summer Tanager's near extirpation from its historic range on the Colorado River, it has increased greatly on the Kern River. Could San Diego County become a region of large-scale Summer Tanager colonization too?

Indigo Buntings appeared more numerously than usual, with seven males in as many squares. The one Jim Wilson and Phil Nelson found at Jacumba was with a female feeding a fledgling. I returned with Jim and Phil on 1 July to study the female further; she was not completely typical of either an Indigo or a Lazuli and may have been a hybrid herself. There are two previous records for San Diego County of a male Indigo mated with a female Lazuli but none of pairs of pure Indigos. Notably, our atlas results show that Jacumba is outside the Lazuli's normal breeding range in San Diego County. Phoenix von Hendy reported a pair of Yellow-headed Blackbirds in the Tricolored colony near Rangeland Road in Ramona (K13), suggesting a second possible nesting site for this species in San Diego County.

Escapees from captivity continue to make news too. Those actually confirmed nesting this year include the Black-throated Magpie Jay and Cardinal: Bill Haas found the nest of the former in Goat Canyon near the Tijuana estuary (W10) and the pair of the latter feeding young in nearby Smuggler's Gulch.

--Philip Unitt

birdatlas@sdnhm.org

Fall 2000 Wrenderings | Wrenderings Archive | Bird Atlas Introduction