Kentucky Warbler

Table

Kentucky Warbler – Accepted
1. 04 Jun 1968		Pt. Loma SD	1984-015	9	J. T. Craig (1970), Roberson (1980)
2. 03 Jul 1972	ASY	Southeast Farallon I. SF	1987-011	14	CAS 69647
3. 21–23 Nov 1972		Eureka HUM	1986-303	14	HSU 7188
4. 01 Jun 1973		Santa Barbara I. SBA	1974-039	3
5. 01–03 Jun 1974		Southeast Farallon I. SF	1975-008	3	ph.
6. 16 Jun 1975		Southeast Farallon I. SF	1989-014	14	ph.
7. 27 May 1977		Ft. Piute SBE	1977-063	4
8. 08 Jun 1977		Oasis MNO	1977-111	4
9. 11–12 May 1979		Southeast Farallon I. SF	1987-110	14	ph.
10. 14 Oct 1980	HY	Goleta SBA	1980-217	7	ph., SBMNH 4372
11. 16 May 1981		Lincoln Park SF	1986-255	11
12. 17–21 May 1981		Morongo Valley SBE	1981-038	7	ph.
13. 04 Oct 1981		Morongo Valley SBE	1983-023	9
14. 27 May 1982		Deep Springs INY	1983-102	9
15. 23 Jun 1982		Southeast Farallon I. SF	1987-111	14
16. 23–24 May 1983		Southeast Farallon I. SF	1987-112	14	ph.
17. 27 Oct 1983		Montaña de Oro State Park SLO	1984-040	11
18. 14–16 Nov 1983		Del Mar SD	1983-089	9	ph.
19. 16 Dec 1983–05 Mar 1984		Goleta SBA	1983-074	9	see frontispiece to this book
20. 29 Dec 1983–06 Mar 1984		Corona del Mar ORA	1984-025	9
21. 19 Oct 1984		California City KER	1992-216	16
22. 09 May 1985		Claremont LA	1988-133	13	ph., LACM 104915
23. 19–20 May 1985		Klamath DN	1985-096	11
24. 19 May 1985		California City KER	1985-105	10
25. 22 May 1985		Ft. Piute SBE	1985-098	10
26. 22 May 1985		Iron Mtn. Pumping Plant SBE	1985-108	11
27. 25 May 1985		Mojave KER	1985-104	10
28. 13 Jun 1985		Rodeo Lagoon MRN	1985-084	10
29. 15 Jun 1985		Mammoth Lakes MNO	1988-256	13	CAS 84059
30. 22–23 Aug 1985		Carpinteria SBA	1986-082	11
31. 15 Sep 1985		Oasis MNO	1986-080	11
32. 10 Jun 1986		Southeast Farallon I. SF	1986-384	12	ph.
33. 11 Jun 1986		Fairhaven HUM	1986-289	11
34. 11 Sep–18 Oct 1986		La Crescenta LA	1986-448	12	ph.
35. 07 Dec 1986–01 Feb 1987		Los Osos SLO	1987-013	12	ph.
36. 05–07 May 1987		Pt. Loma SD	1987-187	12
37. 09 May 1987		Southeast Farallon I. SF	1987-206	12	ph.
38. 10 May 1987		Mojave KER	1987-134	12
39. 13 May 1987		Palomarin MRN	1989-025	14	ph.
40. 15 May 1987		Galileo Hill KER	1987-160	12
41. 16 May 1987		S. Fork Kern R. Preserve KER	1987-166	12
42. 17–24 May 1987		Morongo Valley SBE 1987-183/1987-184	12
43. 25–27 May 1987		Oasis MNO 1987-141/1987-256	12
44. 25–27 May 1987		Deep Springs INY	1987-142	12
45. 27–29 May 1987		Butterbredt Spring KER	1987-165	12
46. 30 May 1987		Furnace Creek Ranch INY	1987-182	12
47. 14–18 Jul 1987	SY	Southeast Farallon I. SF	1987-247	13
48. 13 Aug 1987		Mono Lake MNO	1987-279	13
49. 18–27 Sep 1987	AHY	Coyote Creek near Alviso SCL	1987-272	13	ph.
50. 17 Jun 1988		Southeast Farallon I. SF	1988-154	13	ph.
51. 09–10 Sep 1988	HY	Southeast Farallon I. SF	1988-300	13	ph.
52. 12 Oct 1988	HY	Pt. Loma SD	1990-050	13
53. 19–21 May 1989		Butterbredt Spring KER	1989-091	13
54. 09 Jun 1990		Mojave KER	1990-110	15
55. 14–17 Sep 1990		Pt. Loma SD	1990-130	16
56. 01–03 Oct 1990	HY	Southeast Farallon I. SF	1991-012	16	ph.
57. 21–29 Oct 1990		Pacific Grove MTY	1990-162	16	ph.
58. 27–28 May 1991		Lee Vining MNO	1992-094	17
59. 31 May–01 Jun 1991		Scotty’s Castle INY	1991-071	16
60. 02–04 Jun 1991		Southeast Farallon I. SF	1991-077	16	ph.
61. 25 Aug–02 Sep 1991		Morongo Valley SBE	1991-113	17
62. 15 Sep 1991		Southeast Farallon I. SF	1991-158	17
63. 04–25 May 1992	ASY	Southeast Farallon I. SF	1992-166	18	ph.
64. 09 May 1992		Los Osos SLO	1992-194	18
65. 09–10 May 1992		Galileo Hill KER	1992-152	18
66. 14–15 May 1992	SY	Southeast Farallon I. SF	1992-167	18	Fig. 414, ph.
67. 15–16 May 1992	SY	Southeast Farallon I. SF	1992-168	18	Fig. 414, ph.
68. 15–16 May 1992		Petaluma SON	1993-062	18	ph.
69. 16 May 1992		Carpinteria SBA	1992-156	18
70. 16 May 1992	SY	Southeast Farallon I. SF	1992-169	18	ph.
71. 20 May 1992		California City KER	1992-145	18
72. 22 May 1992		S. Fork Kern R. Preserve KER	1992-195	18	ph.
73. 24 May 1992		Butterbredt Spring KER	1992-196	18
74. 24 May–27 Jun 1992		Donner Pass NEV	1992-161	18	ph.
75-85. 24 May–11 Aug 1992	11	upper Santa Ynez R. SBA	1992-200	18	ph., audio, AB 46:501, Heindel & Patten (1996); breeding not proven
86. 25 May 1992		Furnace Creek Ranch INY	1992-154	18
87. 26 May 1992		Butterbredt Spring KER	1992-232	18
88. 28 May–15 Jun 1992		Mountain Home Village SBE	1992-267	18	audio
89. 31 May 1992		Butterbredt Spring KER	1992-140	18
90. 31 May 1992		Glass Mtn. MNO	1993-063	18
91. 01–02 Jun 1992	ASY	Southeast Farallon I. SF	1992-170	18	ph.
92. 04 Jun 1992		Mojave KER	1992-153	18
93. 06–07 Jun 1992	SY	Southeast Farallon I. SF	1992-171	18	ph.
94. 06–07 Jun 1992		Butterbredt Spring KER	1992-197	18
95. 08 Jun 1992		Pine Valley SD	1992-198	18
96. 12 Jun 1992		Blue Jay SBE	1992-025	18
97. 14–21 Jun 1992		Pacific Grove MTY	1992-157	18	ph., audio
98. 19–22 Jun 1992		vic. Fallbrook SD	1992-201	18
99. 03 Sep 1992		Gaviota SBA	1992-290	18
100. 25 Oct 1992		Galileo Hill KER	1992-276	18	video
101. 30 Jun–19 Jul 1993		Encinitas SD	1993-147	19
102. 16–18 Jul 1993		Wyman Canyon INY	1993-148	19
103. 12 Sep 1993		Goleta SBA	1993-161	19
104. 13 Sep 1993		Southeast Farallon I. SF	1993-207	19
105. 21 Sep 1993		Pt. Loma SD	1994-042	19
106. 10 Oct 1993		Galileo Hill KER	1993-173	19
107. 18–19 Dec 1993		Arcadia LA	1994-079	19	ph.
108. 24 May 1994		Santa Barbara SBA	1994-089	28
109. 22–23 Sep 1994		Galileo Hill KER	1994-196	20	ph.
Kentucky Warbler – Not accepted, identification not established
30 Apr 1979		Coso Junction INY	1980-011	6
24 Oct 1979		Imperial Beach SD	1987-337	14
14 Sep 1980		Cambria SLO	1986-276	14
02 Sep 1985		Carmel R. mouth MTY	1985-145	11
15 Jun 1992		Chilao LA	1992-199	20
Kentucky Warbler – Not submitted
02 Jun 1969		Southeast Farallon I. SF		14	McCaskie et al. (1979), DeSante & Ainley (1980), Pyle & Henderson (1991), Richardson et al. (2003)
18 Jun 1976		Southeast Farallon I. SF		14	Pyle & Henderson (1991),
					Richardson et al. (2003)
04 Oct 1991		Pleasant Canyon INY			FN 51:122
10 Jun 1992		Morongo Valley SBE			AB 46:482
19 Jun 1992		Prado Basin RIV			AB 46:482
04–05 Jun 1993		Butterbredt Spring KER			AB 47:454
10 Jun 1993		S. Fork Kern R. Preserve KER			AB 47:454

Figures

Figure 291. This first-spring male Kentucky Warbler was photographed on 16 May 2004 in Ridgecrest, Kern County, twelve years after the incursion in spring/summer 1992 that precipitated this species’ removal from the CBRC review list (Bob Steele).

Figure 414. California records of the Kentucky Warbler had been building steadily for more than a decade, but no one predicted the incursion of spring/summer 1992, which generated records of at least 38 individuals. This female and male, participants in the event, were photographed on 15 May 1992 on Southeast Farallon Island (1992-167, 1992-168; William J. Sydeman).

Figure 415. Annual occurrence of the Kentucky Warbler. A spike in records during the early 1990s bumped the number of accepted records over 100, prompting the species’ 1994 removal from the CBRC review list.

Figure 416. Distribution of 109 Kentucky Warblers accepted through the end of the review period in 1994, showing concentrations of migrant records from Southeast Farallon Island, oases in eastern Kern County, Pt. Loma in San Diego County, and Morongo Valley in southwestern San Bernardino County. A fifth mapped concentration corresponds to the 1992 incursion of 11 summering birds to the upper Santa Ynez River watershed in eastern Santa Barbara County.

Kentucky Warbler

KENTUCKY WARBLER Oporornis formosus (Wilson, 1811)

Accepted: 109 (96%)	Treated in Appendix H: no
Not accepted: 5	CBRC review: records through 1994
Not submitted/reviewed: 7	Large color image: see Figures

This warbler’s northern breeding limit extends from southeastern Nebraska and southern Wisconsin (where local) east to southwestern Connecticut. The southern limit stretches from eastern Texas east to northern Florida. Migration is primarily through the East and the Caribbean to wintering grounds that extend from southern Veracruz and Nayarit south to Panama. Birds winter rarely south to northern South America and casually or accidentally north to the southern United States, Bermuda, and the West Indies. Vagrants stray regularly to southeastern Canada, casually west to southern central Canada and the Pacific coast (British Columbia south to northern Baja California Sur). The species is an accidental vagrant to northern Alaska.

California’s first Kentucky Warbler was a male captured on 4 June 1968 at Pt. Loma, San Diego County (J. T. Craig 1970). California records increased dramatically starting in the 1980s, including an “invasion” of at least 38 birds during spring/summer 1992 (Terrill et al. 1992, Patten and Marantz 1996) that precipitated cessation of CBRC review (see Figure 415). As with several other vagrants from the Southeast, spring birds (4 May–3 July, peaking mid May to mid June) predominate, accounting for three-fifths of the accepted records (65 of 109). Only about one-fifth (25 of 109) involve fall migrants (13 August–23 November, peaking in September and October).

Fifteen accepted records involve oversummering birds, or birds discovered in midsummer (24 May–11 August). A remarkable total of 11 spent the summer of 1992 in Santa Barbara County’s upper Santa Ynez River during a unique incursion that also produced eight spring/early summer records of this species in Kern County. The same phenomenon also involved White-eyed and Yellow-throated Vireos, Northern Parulas, and Worm-eating and Hooded Warblers—all species with substantial southeastern breeding populations (Patten and Marantz 1996). The generally increasing frequency of occurrence of these species in California, especially in spring and summer, has been mirrored elsewhere in the West (e.g., southeastern Arizona; Rosenberg and Witzeman 1999). Midsummer records of Kentucky Warblers away from breeding habitat—as on Southeast Farallon Island 14–18 July 1987—are open to interpretation but could involve yearlings searching for territories or mates.

Four Committee-endorsed records involve Kentucky Warblers in winter along the coast from San Luis Obispo County southward. The post-review period has brought four more north to Monterey County: 17 December 1995–8 April 1996 in South Laguna, Orange County (Hamilton and Willick 1996); 15–25 March 1999 in Vista, San Diego County (NAB 53:210); 1 January 2001 on the Big Sur River in Monterey County (Roberson 2002; bird not effectively searched for on later dates fide D. Roberson); and 4 January–24 March 2003 in Costa Mesa, Orange County (NAB 57:259, 405).