Supplemental List

The Supplemental List—a subset of the California Bird List—comprises native species recorded in California for which the CBRC has determined that all records of birds of established identity are of uncertain natural occurrence. Species judged by the CBRC to be probable escapees are not admitted to the Supplemental List but are considered to be of hypothetical occurrence in the state (see Hypothetical List). A species of uncertain natural occurrence in California is admitted to the Supplemental List if a majority of members at a meeting votes in favor of placing the species on the Supplemental List. Appendix A contains the CBRC bylaws, and Bylaw VI (I) 6 explains the formal processes by which species are admitted to and removed from the Supplemental List.

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Nazca Booby

NAZCA BOOBY Sula granti Rothschild, 1902

Accepted: 0

Treated in Appendix H: no

Not accepted: 2

CBRC review: all records

Not submitted/reviewed: 0

Click image for larger version

This booby breeds mainly on the Galapagos Islands off Ecuador and on the Malpelo Islands off Colombia, but small numbers breed sympatrically with Masked Boobies on Clipperton Atoll and the Islas Revillagigedo (Pitman and Jehl 1998), where limited interbreeding occurs (fide R. L. Pitman). Although originally described as a distinct species, the orange-billed Nazca Booby was long classified as a subspecies of the Masked. That changed when Pitman and Jehl (1998) documented assortative mating according to bill color and affirmed that the two forms differ consistently in morphometrics, breeding displays, and nest-site selection.

On 27 May 2001, a first-spring Nazca Booby landed on a northbound sportfishing boat approximately 50 nautical miles west of Punta Banda in Baja California and rode it into San Diego Bay, San Diego County (identification confirmed by DNA analyses; T. Steeves in litt.; Figure 319). The bird was captured there on 29 May, taken to a rehabilitation center, and released at San Diego Bay on 22 June 2001. California records of seven immature birds that were either Masked or Nazca Boobies are addressed in another species account (see page 112).

Other records of Nazca Boobies in Mexican waters away from breeding areas include one of 70 adults and subadults over deep water off Michoacán and Guerrero, 28 April–6 May 1992 (Howell and Engel 1993) and another involving an adult in the central Gulf of California in April/May 1992 (Tershy and Breese 1997).

Nazca Booby – Not accepted, identification not established

22 Dec 2002

San Pedro LA

2003-082

29

 

Nazca Booby – Not accepted, natural occurrence questionable (identification established)

27 May 2001

SY

San Diego SD

2001-107

27

Fig. 319, ph., Garrett & Wilson (2003)

 

Demoiselle Crane

DEMOISELLE CRANE Anthropoides virgo (Linnaeus, 1758)

Accepted: 0

Treated in Appendix H: no

Not accepted: 1

CBRC review: all records

Not submitted/reviewed: 0

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This, the smallest species of crane, breeds mainly in central Eurasia and winters on the Indian subcontinent and in sub-Saharan Africa. A disjunct population breeds in Morocco, and during the 20th century the species was extirpated from the Iberian and Balkan Peninsulas and parts of northern Africa and western Eurasia (Archibald and Meine 1996). The species has been recorded in northeastern Siberia (Dement’ev and Gladkov 1951). According to Beaman and Madge (1998), the numerous records from western Europe “most likely refer to escapes,” although Lewington et al. (1991) held otherwise, in at least some instances. An unbanded but microchipped Demoiselle Crane that escaped from a Netherlands zoo “seems to have paired up with a Common Crane, which it now follows on its migrations” (Gantlett 2007). In May 2003 a color-banded bird escaped from captivity in Aylmer, Ontario, near the north shore of Lake Erie. From 18 May 2003 through 2 June 2004 it was periodically sighted as far west as the Holiday Beach Conservation Area, roughly 160 miles from Aylmer (fide A. Wormington). A 10 March 2005 query of the International Species Information System yielded a total of 83 captive Demoiselle Cranes at zoos and other participating institutions in North America, including six in San Diego County, three in Arizona, and one in Washington.

An adult Demoiselle Crane that wintered with Sandhill Cranes in the vicinity of Lodi and Staten Island, San Joaquin County (Figures 320, 449), from 30 September 2001 to 18 February 2002, was probably the same individual photographed on 2 May 2002 with Sandhills near Smithers, British Columbia (Bain 2002). The same bird may also be responsible for an “unsubstantiated sight report” of this species from Gustavus, southeastern Alaska, 13–14 May 2002 (D. D. Gibson in litt.). The California record was accepted by three Committee members, but those in the non-accepting majority noted (a) that all the Sandhill Cranes breeding in Siberia are believed to winter in the Great Plains and (b) that Demoiselle Cranes are relatively common in captivity (see the previous paragraph), with documented records of escapees in North America.

Figure 449. The Demoiselle Crane as it appeared among Sandhill Cranes east of Lodi, San Joaquin County, 8 October 2001. Many believe that this migratory species could reach California unassisted, but most Committee members considered it more likely that this bird escaped from captivity (2001-173; Kevin McKereghan).

Demoiselle Crane – Not accepted, natural occurrence questionable (identification established)

30 Sep 2001–19 Feb 2002

AHY

vic. Lodi/Staten I. SJ

2001-173

28

Figs. 320, 449, ph., NAB 56:102

 

 

Blue Mockingbird

BLUE MOCKINGBIRD Melanotis caerulescens (Swainson, 1827)

Accepted: 0

Treated in Appendix H: no

Not accepted: 1

CBRC review: all records

Not submitted/reviewed: 0

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Blue MockingbirdThis Mexican endemic is resident from southern Sonora and southern Tamaulipas south to Oaxaca. The species occurs casually in Nuevo León and southern Arizona, and a questionable report comes from eastern Chiapas (AOU 1998). In southern Texas (Weslaco, Hidalgo County), a bird present intermittently between 9 May 1999 and 27 February 2002 aroused some controversy over its origin (NAB 53:302, 56:73). Just months later and in the same county, a first-fall bird was recorded in Pharr from 28 September 2002 to 26 May 2003 and from mid September 2003 to 19 October 2004 (Lockwood 2004, 2005). Commenting on the Pharr bird’s first recorded stay, Lockwood and Freeman (2004) expressed no reservations about the species’ status as a natural vagrant, but Lockwood (2005:21), publishing after the 2003/2004 visit, included this caveat: “The extended stay of this bird (as well as the other Blue Mockingbird found in Texas) has led some observers to question its origin.” Nevertheless, the Texas Bird Records Committee accepted both the Weslaco and Pharr records.

California’s only record of the Blue Mockingbird was furnished by a characteristically furtive but widely seen adult that was present from 5 December 1999 to 25 March 2000 in Long Beach, Los Angeles County (Figure 325). From McKee and Erickson (2002): “Most members believed it possible for this species to reach California naturally, but the record received only one accept vote in each of two circulations. Location, age, and the presence of a short, white tenth primary (possibly suggesting a response to stress from prior captivity) all weighed against the record. . . . On the basis of the Long Beach record, the Blue Mockingbird was added to the Supplemental List of California birds at the CBRC’s January 2002 meeting.”

Blue Mockingbird – Not accepted, natural occurrence questionable (identification established)

05 Dec 1999–25 Mar 2000

AHY

Long Beach LA

1999-208

26

Fig. 325, ph., McKee & Erickson (2002)

 

 

Gray Silky-flycatcher

GRAY SILKY-FLYCATCHER Ptilogonys cinereus Swainson, 1827

Accepted: 0

Treated in Appendix H: no

Not accepted: 6

CBRC review: all records

Not submitted/reviewed: 0

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This elegant bird is a resident of highlands from southern Sonora and southern Coahuila south to Guatemala. Phillips (1991) provided evidence that northerly birds may withdraw to the southern part of the range in winter. The species is considered an accidental stray to southern and western Texas (AOU 1998, Lockwood and Freeman 2004), but “Reports from California and Arizona are usually regarded as escaped cage-birds” (AOU 1998). Howell et al. (2001) questioned the natural occurrence of one collected on 7 October 1994 in northwestern Baja California (Cota-Campbell and Ruiz-Campos 1995). Hamilton (2001) encountered a single bird for sale during 13 visits to stores and vendors in northern Baja California from 1999 to 2001 and later observed eight for sale south of Tijuana on 17 September 2002 (R. A. Hamilton unpubl. data).

The first of California’s five records of the Gray Silky-flycatcher refers to a bird photographed on 9 April 1976 in Ventura, Ventura County. The Committee placed this species on the Supplemental List in 1993 but removed it in 1995 because the possibility of escapees was felt to be too high; at least two California birds showed features suggesting prior captivity (see, e.g., Figure 323). The species was returned to the Supplemental List in 2000, when a clean-looking male established a winter territory in the Santa Ana Mts. of Orange County from 29 January to 19 February 1999 (Figure 324). Three members voted to accept this record during each of two rounds of voting.

Binford (1985) wrote: “California records of Mexican species are difficult to assess because we do not know how many such birds are imported illegally, released by returning American tourists or immigrant Mexicans, or lost from U.S. zoos or from pet shops, especially those near the border in Mexico (e.g., Tijuana). In such cases the Committee prefers to await the development of a clear pattern of vagrancy in regions between California and the normal range. Rejected records remain in the CBRC files and may be resubmitted should a pattern be detected. Observers should report to the Committee all possible escapees—if they are also possible wild birds. Only then can a pattern be discerned.”

Gray Silky-flycatcher – Not accepted, identification not established

04 Jun 1983

 

Pt. Loma SD

1993-146

23

 

Gray Silky-flycatcher – Not accepted, natural occurrence questionable (identification established)

09 Apr 1976

Ventura VEN

1980-115

7

ph.

24 May 1993

Pt. Loma SD

1993-115

22

10–12 Mar 1994

SY female

Poway SD

1994-075

20

Fig. 323, ph.

29 Jan–19 Feb 1999

ASY male

Blue Jay Campground ORA

1999-051

25

Fig. 324, ph., video, cover of NAB 53(2), Chu (2005:296) with incorrect county

16 Jun–18 Aug 1999

Pt. Loma SD

1999-121

25

 

 

Black-backed Oriole

BLACK-BACKED ORIOLE Icterus abeillei (Lesson, 1859)

Accepted: 0

Treated in Appendix H: no

Not accepted: 1

CBRC review: all records

Not submitted/reviewed: 0

Click image for a larger version

This oriole breeds from Michoacán and central Veracruz north to central Durango and Nuevo León, where it hybridizes with the closely related Bullock’s Oriole (with which it is sometimes lumped). The species winters south to Oaxaca, with no extralimital reports known from the literature.

Although the Black-backed Oriole is considered only a marginal candidate to reach California as a natural vagrant, when a male appeared in the same part of the Tijuana River valley in San Diego County during spring/summer in both 2000 and 2001 (seemingly wintering elsewhere), the Committee voted unanimously to accept the record (Figure 326). It was reasoned that an escapee would be very unlikely to complete a full migration circuit in this manner, and some members speculated that the bird had perhaps taken up with Bullock’s Orioles that summer in the Tijuana River valley and that presumably winter within the Black-backed Oriole’s range in mainland Mexico. Members also cited similarities with the Streak-backed Oriole, a partially migratory Mexican species that occasionally reaches southern California (although its range extends to near the Arizona border, well north and west of the Black-backed’s). Finally, the species is not known to be kept as a captive anywhere near the international border, reducing the chances that the bird was an escapee. Shortly after the vote was tallied, however, the Black-backed Oriole was detected in its favored eucalyptus stand—in the middle of winter! This unexpected development undercut the most persuasive arguments for the bird’s natural occurrence, and the record received only two votes for acceptance in an unusual supplemental round of voting.

Black-backed Oriole – Not accepted, natural occurrence questionable (identification established)

09 Apr–01 Jul 2000

ASY male

Tijuana R. valley SD

2000-073

27

Fig. 326, ph.

and 28 Apr–04 Jul 2001

 

2001-074

27

ph., video

and 02–13 Jan 2002

 

2002-020

27

 

 

 

Oriental Greenfinch

ORIENTAL GREENFINCH Carduelis sinica (Linnaeus, 1766)

Accepted: 0

Treated in Appendix H: no

Not accepted: 2

Years reviewed by CBRC: all records

Not reviewed/submitted: 0

Color image: none

This finch breeds from extreme southeastern Siberia and Kamchatka south to central and eastern China, Japan, and the Bonin and Volcano Islands. The northernmost subspecies, C. s. kawarahiba, which is larger, larger-billed, and browner than the resident mainland forms, breeds in Kamchatka and Sakhalin and winters south through Japan to Taiwan (Brazil 1991). This subspecies occurs casually in the western Aleutian Islands during migration.

The record of a widely seen Oriental Greenfinch present from 4 December 1986 to 3 April 1987 in Arcata, Humboldt County, circulated four times through the Committee and gained five or six votes of acceptance during each round (9 of the 16 members to vote on the record never took this position). Members generally agreed that the record pertains to kawarahiba, a requisite for consideration as a genuine vagrant. Factors weighing against the bird’s natural occurrence include the species’ failure to establish a pattern of vagrancy in the Old World, known instances of captivity in the United States, and perhaps this individual’s unusual association with House Finches. Thus, while most members considered the odds of this bird being an escapee to be small, the record never mustered the support needed for the CBRC to endorse it as involving a naturally occurring vagrant.

In Taiwan, wintering birds are apparently captured and kept (Yen 1984). In the United States, the species is rare, but not unknown, in captivity. A 10 March 2005 query of the International Species Information System yielded a total of eight captive Oriental Greenfinches at zoos and other participating institutions in North America: five in Quebec and three in Manitoba.

Oriental Greenfinch – Not accepted, identification not established

17 Apr 1988

Arcata HUM

1988-119

15

 

Oriental Greenfinch – Not accepted, natural occurrence questionable (identification established)

04 Dec 1986–03 Apr 1987

Arcata HUM

1986-450

15

ph., Patten & Erickson (1994)