[EBB Sightings] Still more Winter Wrens

Hi all,
One last word from me about Winter Wrens, prompted by
Phila's recent post. Sorry this account hasn't yet
been edited, as you will soon see. Too bad we weren't
able to get Phile to write the atlas...
Steve Glover
Dublin, CA

Winter Wren  (Troglodytes troglodytes)

The bubbly little Winter Wren and it's song that never
seems to end is a scarce commodity in Contra Costa
County, having invaded only recently and with little
chance of becoming more common.

Current status and distribution
The Winter Wren, like the redwood, is a member of the
humid, coastal forest and, like the redwood, is
present only locally in Contra Costa County. Each of
the countys known breeding Winter Wrens is present in
the western Berkeley hills, from Tilden Park south to
Redwood Regional Park and including Pinehurst Rd. to
the east, a total of only five blocks. In truth,
suitable habitat exists nowhere else in the county. 
Preferred haunts almost inevitably feature shady,
moist streamside habitat composed of sparse shrubbery,
ferns and fallen logs. Occasionally, such as around
Jewel Lake at Tilden Park, the species inhabits the
floor of heavily forested hillsides with a dense,
riotous undergrowth of blackberry, thimbleberry and
poison oak. 

Historical occurrence
Grinnell and Wythe (1927) were unaware of any Winter
Wrens breeding in the Bay area away from the immediate
coast and there appears to be no suggestion of East
Bay nesting until the 1990s other than the
categorization of the species as assumed nesting
(Erickson 1989). The first Contra Costa County nesting
confirmation was from the Stream Trail in Redwood
Regional Park 24 Jun 1992 (pers. obs.). Although it is
tempting to think that little Troglodytes was present
and breeding all along, the Berkeley hills have been
well explored, even during the first half of the 20th
century, by naturalists unlikely to overlook the
species and it?s distinctive vocalizations. 

Breeding and natural history
Our three breeding confirmations consist of an adult
carrying food 6 May, a fledgling on 18 May and an
adult carrying a fecal sac from the nest on 2 June. In
San Mateo County, nest-building was detected as early
11 Apr and a nest with eggs was found 23 Apr.
Fledgling detections there ranged from 21 May-21 Jul
(Sequoia Audubon Society 2001). Food carrying by
adults was confirmed in Humboldt County, northwestern
California, between 12 May and 20 Jul (Hunter et al.,
2005). 
	Although small numbers of the Winter Wren  assumed to
derive from northern populations are detected in
Contra Costa County during migration and in winter,
our tiny breeding population is presumed to be
sedentary.

Conservation
	It is fortunate indeed that the entirety of Contra
Costa County?s small population of Winter Wrens
resides in acreage protected by either the East Bay
Regional Parks District or the East Bay Municipal
District.