Date: 4/17/25 8:01 am From: Brian Fitch via groups.io <fogeggs...> Subject: Re: [EBB-Sightings] [CALBIRDS] April migration: Late and Slow! , Some annual early questionable reports
Good Morning Birders,
I've just returned from a week of camping at a notable migration passage
area, and because of the synchronicity with the above forwarded message,
I'll chime in.
I was in the desert of eastern San Diego County, at a well known site, a
site that has been consistently productive in spring since I first started
camping there in 1991. The species mix this year was certainly odd, with
early, normal, and late arrivals, as well as late stayers all represented.
There were unprecedented numbers (for this site and time) of Bullock's
Orioles and Brewer's Sparrows, and high numbers of Ash-throats, western
warblers, grosbeaks, and buntings. Empids and vireos seemed to be just
arriving. There was an impressive movement on the 12th and 13th, with many
mesquites and ocotillos having multiple birds hanging from them, either
taking nectar or gleaning tiny green worms. Most of the migrants were gone
by the 14th, so that mob will be showing up soon somewhere further north.
There were other mountain or basin species staying late besides the
Brewer's, and good numbers of resident desert species despite the earlier
extreme drought conditions.
The single most striking and sad issue was not running into another birder
for the first time since 1991, not at this site, at other local known
sites, or at the Salton Sea. In every previous spring, I've met and shared
news with more than one birder, or groups of birders. I think it's quite
possible that migration is moving oddly but at a good pace, but birders are
either not out in the field in decent numbers, or are clustering at "top
ten hotspots." The behavior of birders might be a bigger part of
phenomenology than we take into account.
Brian Fitch
On Wed, Apr 16, 2025 at 1:09 PM Dominik Mosur via groups.io <dominikmosur=
<gmail.com...> wrote:
> A very informative post from Paul Lehman regarding this year's spring
> migration and related matters. It's from Southern California but highly
> applicable here as well.
>
> Dominik Mosur
>
> ---------- Forwarded message ---------
> From: <lehman.paul...> via groups.io <lehman.paul=
> <verizon.net...>
> Date: Wed, Apr 16, 2025 at 12:06 PM
> Subject: [CALBIRDS] April migration: Late and Slow! , Some annual early
> questionable reports
> To: <calbirds...> <calbirds...>
>
>
> I think almost everyone in California would agree that the passerine
> migration so far this April is notably LATE and SLOW. Down here in parts of
> southern California, a number of folks (including myself) have commented on
> it being a good migration earlier in the season for Violet-green Swallow,
> and since then OK for Western Kingbird and Chipping Sparrow. But almost
> everything else.....late and slow! One very common refrain virtually
> statewide has been, "Where are all the Hooded Orioles?" Here in San Diego
> County, where common and widespread, they were remarkably scarce until just
> a little over a week ago. Still below average, but at least they have
> filled in a fair bit of their widespread range locally--but this is almost
> A FULL MONTH LATE. Bullock's Orioles and Black-headed Grosbeaks have also
> finally begun to increase, but still below normal and running 2-3 weeks
> late. And where are all the many Ash-throated Flycatchers that normally
> start appearing by late March? Anyway, the list goes on and on. So, what's
> happening? Major population declines? Inappropriate local weather
> conditions locally for migration? Or something odd going on farther to the
> south(east), either en route or closer to the wintering grounds? In support
> of the latter factor are reports that a fair chunk of southern Arizona had
> it driest winter on record, EVER, and--perhaps more important--one friend
> of mine reported that parts of Mexico had a cooler or colder than usual
> (relatively speaking) winter and early spring--which could well translate
> into a lot of stuff running late. We will certainly know a lot more once
> the next month plays out!
>
>
> It's another first half of April, and yet another year of multiple reports
> of the following species that are way early and which in most cases likely
> reflect misidentifications. (And all of which could really use photo
> documentation.) Western Wood-Pewees are not expected to start arriving
> until after about 15 April, so any reports before that need to come with
> strong documentation, and need to be flagged by eBird filters. (For
> example, the all-time early arrival in San Diego County is around 8 April.)
> Most such early reports involve either heard-only birds (think vocalizing
> starlings or a number of other mimics) or are poorly documented and have no
> photos. Often these reports are from observers who do not at all appreciate
> how unusually early their bird would be. And a problem that I bet many
> birders don't realize is that the first Olive-sided Flycatchers actually
> arrive before wood-pewees do--and probably get misidentified. This month,
> there were several poorly documented early reports, but also one well
> photographed bird in Orange County on 10 April. The next species is
> Swainson's Thrush, which already has a bunch of reports in California
> during the first half of the month. This species is not reliable until
> around late the third week in the month, with a just a few documented
> records as early as the 12th-15th. A fair number of the earliest records
> are of birds at breeding sites, arriving even earlier than through-migrants
> do farther to the SOUTH, but such local breeders need to be heard SINGING.
> Unfortunately, almost all of the early reports this month have involved
> birds not seen and only heard calling, or heard calling and seen rather
> poorly, again mostly by folks who don't appreciate the true status of this
> species so early--and who report the bird giving the "wink" or "wheet" call
> only, but some other species (e.g., Song Sparrow) can give similar calls.
> Last but not least comes Black Swift. There are a small number of legit
> records for the last week or perhaps ten days of April in California (some
> associated with southern or lowland nesting areas), but of course this
> species is a notorious late arriver and typically doesn't show until into
> May. The problem here is the usual one of an observer not appreciating the
> true status and seasonal timing, and either seeing a White-throated or
> Vaux's Swift at a distance or in mediocre light and not properly assessing
> size and/or color. And the other recurring problem is misidentifying male
> Purple Martins. Heck, some especially early reports of Black Swift, if
> indeed of a large all-dark swift, might need to also consider either Common
> Swift or White-collared Swift. So far this year, there have already been
> one or two Black Swift reports. From previous years, there is an especially
> "egregious" report with very limited details coming from Butte County on 30
> March 2021 and apparently being validated by eBird.....
>
>
> Anyway, I'd recommend all county ebird filters be tightened for these and
> several other migrants that are notoriously reported "too early" almost
> every spring (e.g., add Willow and Dusky Flycatchers to the list), and set
> to 0 until these species are truly known to occur REGULARLY in at least
> small numbers.
>
>
> Exceptional arrival and departure dates certainly DO exist. But such
> exceptional occurrences need to be appreciated by the observer AT THE TIME
> OF THE OBSERVATION and need to be exceptionally well documented.
>
>
> --Paul Lehman, San Diego
>
>
>
>
>
