Prepared by David L. Suddjian, 11 September 2000
Santa Cruz
Bird Club Bird Records Keeper
Recent questions about an Empidonax flycatcher
at Natural Bridges S. B. prompted this look at the accepted records of
rare “Empids” in Santa Cruz County, California. Empidonax flycatchers
present great challenges for field identification. Our knowledge of identification
of these birds has advanced greatly in recent years. For the most part,
though, the rare species probably slip by undetected or unnoticed. There
is still much to learn, and it is wise to remain respectful of the difficulties
that remain. Correct identification of the species that are rare in coastal
California often requires prior field experience with these same species
(easiest to obtain on their breeding grounds) and identification resources
which extend beyond the standard field guides.
Pacific-slope Flycatcher (E. difficilis) is,
of course, the familiar member of the genus in Santa Cruz County. It is
present as a common migrant and breeder from mid-March to mid-October,
with occasional late fall and winter records. Willow Flycatcher (E.
traillii) is much less numerous, but occurs regularly in small numbers
during spring migration (mostly late May into June) and somewhat more commonly
during fall migration (county records span 23 August to 22 October). See http://santacruzbirdclub.org/recwilfc.html
for a summary of its occurrence in the fall. There is also one winter record
– 1-2 January 1986.
Four other species have been found only rarely: Least
Flycatcher (E. minimus), Hammond’s Flycatcher (E. hammondii),
Gray Flycatcher (E. wrightii) and Dusky Flycatcher (E. oberholseri).
Santa Cruz County records of these four are summarized below. Additional
species might be identified in the county in the future. Yellow-bellied
Flycatcher (E. flaviventris) and Alder Flycatcher (E. alnorum)
have been found extremely rarely in California. Cordilleran Flycatcher
(E. occidentalis) nests locally in the Great Basin region of California,
and might occur along the central coast in migration or winter. But at
present, separation of such birds from Pacific-slope Flycatcher in the
field appears to be beyond our grasp.
Table 1 lists the accepted county records of Least,
Hammond’s, Gray and Dusky flycatchers through September 11, 2000. The records
reflect the recent improvements in identification skills, as 76% of all
the records date from 1992 onwards. Table 2 gives the rates of occurrence
per season for the recent five-year period 1995-1999. As a group, fall
records are strongly oriented toward localities within two miles of the
coast, while spring records range further inland.
Least Flycatcher. Two records of spring (29
June) and fall (14 October) migrants. The 29 June 1896 record is based
on a specimen (#416578) at the United Stated National Museum, and was the
first record for California (D. Roberson. 1980. Rare Birds of the West
Coast). This specimen was apparently mislabeled as a “Traill’s” Flycatcher,
then re-evaluated years later and found to be a Least Flycatcher. I hope
to learn more about the story behind this record. Based on records elsewhere
along the central coast, this species is overdue for a recent record from
Santa Cruz County.
Hammond’s Flycatcher. Fourteen records. Ten
records of spring migrants spanned 14 April to 6 June. Note that the three
records from U.C. Santa Cruz records on 28-29 April 1987 were all in different
parts of the campus. Four records of fall migrants spanned 29 August to
29 October. All were of birds seen for one day only. See below regarding
records of unidentified Empidonax.
Gray Flycatcher. Eight records. Two spring
records were 10 and 12 May. Six fall records spanned the narrow period
of 18 September to 10 October. At least one fall migrant was noted to linger
for 3 days.
Dusky Flycatcher. Six records. Two spring records
were 7 and 27 May. Two fall records were 13-15 September and 4-6 October.
Two records of over-wintering birds were 26 January to 21 February and
19 November to 1 March.
Unidentified Empidonax. Six other records
reported by skilled observers were not conclusively identified. These included
probable Hammond’s in May (2), September (2) and December, and a probable
Dusky on 29 August.
The probable December Hammond’s was the most interesting
of these unidentified birds. It was at Wilder Ranch 13-17 December 1990,
until the infamous “Big Freeze” forced it to move on or die. It illustrates
the difficulty of positive field identification of these species. It was
found and thoroughly studied by Doug George, a careful and skilled observer.
He prepared a detailed five-page description and analysis of the bird’s
identity. In the end, even this analysis left him uncertain of what it
was, as he concluded it was likely a Hammond’s but it might have been a
Least Flycatcher.
Table 1. Accepted records of rare Empidonax
flycatchers in Santa Cruz County, CA, through September 11, 2000.
|
Species
|
Date
|
Location
|
Observers
|
|
|
|||
|
Least
Flycatcher
|
29
Jun 1896
|
Santa
Cruz
|
U.
S. National Museum
|
|
|
14-Oct-84
|
Pajaro
River
|
K.
Van Vuren
|
|
|
|
|
|
|
Hammond's
Flycatcher
|
28-Apr-87
|
U.
C. Santa Cruz
|
D.
Suddjian
|
|
|
29-Apr-87
|
U.
C. Santa Cruz
|
B.
Mori +
|
|
|
29-Apr-87
|
U.
C. Santa Cruz
|
B.
Mori +
|
|
|
4-Oct-94
|
Yellow
Bank Creek
|
D.
Suddjian
|
|
|
14-Apr-95
|
Meder
Canyon
|
S.
Gerow
|
|
|
10-May-95
|
U.
C. Santa Cruz
|
S.
Gerow
|
|
|
29-Oct-96
|
Meder
Canyon
|
S.
Gerow
|
|
|
10-Sep-97
|
Meder
Canyon
|
J.
Davis
|
|
|
30-May-98
|
Noble
Gulch
|
D.
Suddjian
|
|
|
31-May-98
|
Liddell
Creek
|
C.
Emmons
|
|
|
4-Jun-98
|
Live
Oak
|
P.
Radcliff
|
|
|
6-Jun-98
|
Sycamore
Grove
|
D.
Suddjian
|
|
|
21-Sep-98
|
Soquel
Creek, Soquel
|
D.
Suddjian
|
|
|
20-May-00
|
Schwan
Lake
|
D.
Suddjian
|
|
|
|
|
|
|
Gray
Flycatcher
|
12-May-75
|
Pajaro
Dunes
|
J.
& R. Warriner
|
|
|
10-May-88
|
Summit
Ridge at Lomita
|
D.
Suddjian
|
|
|
6-Oct-92
|
Wilder
Creek
|
D.
George
|
|
|
18-20
Sep 94
|
Natural
Bridges S. B.
|
S.
Gerow +
|
|
|
25-Sep-94
|
Rancho
Del Oso
|
E.
Lebow
|
|
|
7-Oct-95
|
Monterey
Bay Academy
|
D.
Suddjian
|
|
|
10-Oct-96
|
Noble
Gulch
|
D.
Suddjian
|
|
|
1-Oct-98
|
Yellow
Bank Creek
|
D.
Suddjian
|
|
|
|
|
|
|
Dusky
Flycatcher
|
4-6
Oct 93
|
Natural
Bridges S. B.
|
D.
Suddjian +
|
|
|
26
Jan - 21 Feb 94
|
Sycamore
Grove
|
D.
George +
|
|
|
19
Nov 94 - 1 Mar 95
|
Natural
Bridges S. B.
|
D.
Suddjian, S. Gerow +
|
|
|
27-May-98
|
Pajaro
River
|
D.
Suddjian
|
|
|
7-May-99
|
Scott
Creek
|
D.
Suddjian
|
|
|
13-15
Sep 99
|
Sycamore
Grove
|
D.
Suddjian
|
Table 2. Recent 5-year averages (1995-1999) by season.
|
|
Spring
|
Fall
|
All Year
|
|
Least
Flycatcher
|
0.0
|
0.0
|
0.0
|
|
Hammond's
Flycatcher
|
1.2
|
0.6
|
1.8
|
|
Gray
Flycatcher
|
0.0
|
0.6
|
0.6
|
|
Dusky
Flycatcher
|
0.4
|
0.2
|
0.8
|