15776What is true spring status of Plumbeous Vireo in CA??
- Apr 14, 2014Every spring during April there are a number of Plumbeous Vireo reports
in coastal southern California and out in the southeastern deserts.
Unfortunately, very, very few of these reports are well documented. And
whereas this species is certainly a rare-but-regular fall and winter
visitor to s. California (very rare to casual in coastal northern CA),
that status does not extend to the spring season. And this is true even
for the southeastern deserts, much less the coastal slope. However, it
appears that the conventional wisdom among many birders is that this
species is semi-expected as a SPRING MIGRANT in these same areas. One
friend who is the eBird reviewer for one of the southern CA counties
tells me that he has received a fair number of reports to review during
the past couple weeks (and in previous springs), but very few of which
contain any sort of contemporary adequate documentation, and which were
often seen by people who failed to appreciate AT THE TIME OF THE
SIGHTING how very rare such a bird would be. Some of these reports are
from areas where individual Plumbeous were known to have wintered. But
many are not. Wintering Plumbeous regularly remain well in to April--at
least to mid-April and a few times through late April. And wintering
birds can easily be missed earlier in the season, or then turn up at a
"new location" in early spring as many wintering birds shuffle about on
a local scale in response to shifting vegetation attractability and thus
changing food supply.
This whole situation is made more complicated, of course, by the ease
with which some of the duller spring Cassin's Vireos can be
misidentified as Plumbeous Vireos--and certainly Cassin's is the
expected "Solitary" Vireo during spring in ALL these areas.
Many spring records of Plumbeous Vireos from a number of counties from
back in the 1970s, 1980s, and 1990s are properly being reassessed by the
local records-keepers and others. Some are probably now thought of as
lingering winter birds rather than true spring migrants, and some will
properly be 'let go' as being inadequately documented at the time. We
just didn't know back then.... There have certainly been major advances
in our knowledge of Solitary Vireo ID and status/distribution over the
past several decades.
Most of the very few "good" records of spring migrant Plumbeous are from
May (including on the southeastern deserts), and there is even an early
June record from Orange County back in 1993.
In sum, CAN migrant Plumbeous Vireos occur in spring? Yes. But have
they been over-reported at this season? Definitely yes. I guess we
should all take one giant step backwards and take extra care in making
future spring reports of this species, particularly when the bird does
not clearly involve a lingering winter bird.
--Paul Lehman, San DiegoPosted by Barbara Carlson, San DiegoPosted by