Date: 9/18/25 7:45 am From: naturestoc via groups.io <Naturestoc...> Subject: Re: [CALBIRDS] Apparent Dark-sided Flycatcher at Charleston Marsh, Santa Clara County
Dark-sided flycatcher has been seen off and on since sunrise at the original spot Dan Brown Sacramento. Sent from my Verizon, Samsung Galaxy smartphone -------- Original message --------From: "Aidan Sinha via groups.io" <aidansinha...> Date: 9/17/25 10:40 PM (GMT-08:00) To: <CALBIRDS...> Subject: Re: [CALBIRDS] Apparent Dark-sided Flycatcher at Charleston Marsh, Santa Clara County All, After appearing sporadically during the day, the bird made a final appearance around 7:00 PM in the area just across Charleston Road from where it had been earlier. A bird that appeared to be the flycatcher initially showed up on a tree in the parking lot, and shortly after, those of us present were able to get definitive looks on the flycatcher as it perched up on the tops of several conifers at roughly 37°25'13.9"N 122°04'21.8"W. For those who chase tomorrow, please note that the parking lots in the area are private property and inaccessible - please view and search for the bird from the street sidewalks and from the trails around the marsh. For additional details about the area (including parking details) see the SCVBA page here (https://scvbirdalliance.org/self-guided-birding/charleston-road-marsh). Good luck to those who search tomorrow, congrats to Eve Meier and Patricia Lynch on this find and Garrett Lau on the refind, and thanks to all who reported this and provided details!  Aidan Sinha San Jose
Date: 9/17/25 10:40 pm From: Aidan Sinha via groups.io <aidansinha...> Subject: Re: [CALBIRDS] Apparent Dark-sided Flycatcher at Charleston Marsh, Santa Clara County
All,
After appearing sporadically during the day, the bird made a final appearance around 7:00 PM in the area just across Charleston Road from where it had been earlier. A bird that appeared to be the flycatcher initially showed up on a tree in the parking lot, and shortly after, those of us present were able to get definitive looks on the flycatcher as it perched up on the tops of several conifers at roughly 37°25'13.9"N 122°04'21.8"W. For those who chase tomorrow, please note that the parking lots in the area are private property and inaccessible - please view and search for the bird from the street sidewalks and from the trails around the marsh. For additional details about the area (including parking details) see the SCVBA page here ( https://scvbirdalliance.org/self-guided-birding/charleston-road-marsh ). Good luck to those who search tomorrow, congrats to Eve Meier and Patricia Lynch on this find and Garrett Lau on the refind, and thanks to all who reported this and provided details!
Date: 9/17/25 2:46 pm From: <tgmiko...> via groups.io <tgmiko...> Subject: Re: [CALBIRDS] Apparent Dark-sided Flycatcher at Charleston Marsh, Santa Clara County
As soon as anybody sees the flycatcher tomorrow, Thursday morning, please
post here to this email list immediately.
Tom Miko (Polar Bear Whisperer)
Claremont 91711
909.241.3300
On Wed, Sep 17, 2025, 2:06 PM Thomas Benson via groups.io <tbenson=
<csusb.edu...> wrote:
> Birders,
>
> An apparent Dark-sided Flycatcher was found this morning at Charleston
> Marsh in Santa Clara County and is still being seen this afternoon. Exact
> location of the bird is here: 37.4211198, -122.0729803. Parking is
> apparently limited. Original eBird report here (under Empidonx sp.):
> https://ebird.org/checklist/S273917582. This would be a first California
> record, if confirmed, so of course the CBRC would appreciate documentation:
> https://www.californiabirds.org/report_sighting.html.
> Tom
>
> Thomas A. Benson
> Secretary, California Bird Records Committee
>
>
>
Date: 9/17/25 2:17 pm From: Aidan Sinha via groups.io <aidansinha...> Subject: Re: [CALBIRDS] Apparent Dark-sided Flycatcher at Charleston Marsh, Santa Clara County
All,
For those unfamiliar with the location, the Santa Clara Valley Bird Alliance has a page about the location here ( https://scvbirdalliance.org/self-guided-birding/charleston-road-marsh ). According to the site regarding parking in the area, those who chase can use Lot C at the Shoreline Amphitheatre or the Kite Flying area parking at Shoreline. Congrats to Eve Meier and Patricia Lynch on this find! I believe in addition to being a first state record, this is also the first in the Lower 48 (at least on eBird). Good luck to all who chase!
Date: 9/17/25 2:06 pm From: Thomas Benson via groups.io <tbenson...> Subject: [CALBIRDS] Apparent Dark-sided Flycatcher at Charleston Marsh, Santa Clara County
Birders,
An apparent Dark-sided Flycatcher was found this morning at Charleston Marsh in Santa Clara County and is still being seen this afternoon. Exact location of the bird is here: 37.4211198, -122.0729803. Parking is apparently limited. Original eBird report here (under Empidonx sp.): https://ebird.org/checklist/S273917582. This would be a first California record, if confirmed, so of course the CBRC would appreciate documentation: https://www.californiabirds.org/report_sighting.html.
Tom
Thomas A. Benson
Secretary, California Bird Records Committee
Date: 9/4/25 6:45 pm From: John Sterling via groups.io <jsterling...> Subject: [CALBIRDS] Spoonbill in kern county
The Roseate Spoonbill, now in adult plumage was photographed today at the kern water bank off Hwy 5 Buttonwillow. Some water is starting to be released. I’ll be back there next week and if it’s still there I’ll get the word out about logistics for meeting to see the bird.
John
John Sterling
530 908-3836
26 Palm Ave
Woodland, CA 95695
Date: 9/2/25 10:09 am From: Kimball Garrett via groups.io <cyanolyca818...> Subject: [CALBIRDS] CBRC news: Stejneger's Scoter added to California state list
Birders,
The California Bird Records Committee has accepted the record of a
Stejneger's Scoter photographed at the end of Zils Road near Watsonville,
Santa Cruz Co on 15 January 2014. This species is placed on the list after
White-winged Scoter, with a "P" code (photographed, no specimen) and
an asterisk (on review list). The California list now stands at 691 species
(including 17 naturalized non-native species).
[Those not interested in CBRC "sausage making" may wish to skip the
following]
In its initial circulation in 2019 this record received 7 Accept votes and
2 Not-Accept votes. When recirculated its support declined to only 3 Accept
votes. With the publication of some important identification material since
that time, and increased field experience by some Committee members and
outside consultants, the Committee agreed after its January 2025 meeting to
circulate the record again. This new circulation resulted in a 8 Accept to
1 Not Accept vote, and thus the record now stands as accepted. Those
expressing concern about the identification as Stejneger's agreed that the
bird (an adult male) showed characters of Stejneger's but that some key
characters (e,g., exact bill color and bill knob shape) were not easy to
scrutinize given the quality of the photographs. Also, a recent paper
documenting a putative White-winged x Stejneger's hybrid at Nome, Alaska
raised the possibility that the California bird could have been a hybrid.
In the end the Committee consensus dismissed the likelihood the bird was a
hybrid and agreed that the bill color and shape, white "eye slash" shape,
and black sides and flanks confirmed it as Stejneger's.
For further reading on this identification issue, see:
Dunn, J. L.,, Gibson, D. D., Iliff, M. J., Rosenberg, G.H., and Zimmer, K.
J. 2012. Alaska records of the Asian White-winged Scoter. Western Birds
43:220-228.
https://archive.westernfieldornithologists.org/archive/V43/WB43(4)-Dunn_et_al.pdf Garner, M., Lewington, I., and Rosenberg, G. 2004. Stejneger’s Scoter in
the Western Palearctic and North America. Birding World 17: 337-347.
Huhtinen, H., Andrejeff, S., and Kononen, J. 2025. Distinguishing Velvet,
White-winged and Stejneger’s Scoter in female-type plumage based on bill
feathering. Dutch Birding 47: 27-34.
López-Velasco, D., Lonergan, P. and Mullarney, K. 2025. Presumed
Stejneger’s x White-winged Scoter hybrid at Cape Nome, Alaska, in June
2024. Dutch Birding 47:35-38.
Date: 8/14/25 7:51 am From: Kimball Garrett via groups.io <cyanolyca818...> Subject: [CALBIRDS] California Bird Records Committee News
Birders,.
The California Bird Records Committee has accepted the record of a Song Thrush (*Turdus philomelos*) from Southeast Farallon Island, San Francisco Co 11-12 November 2024. Joe Morlan has updated the CBRC website to reflect this addition, placed between Eyebrowed Thrush and Rufous-backed Robin the list sequence. Addition of this species brings the California bird list to 690 species.
With the publication of the 66th Supplement to the AOS Check-list of North American Birds (Ornithology, v.142, "July" 2025 -- though publication delayed to mid-August), some other changes have been made to the state list. These include (1) Species sequence changes within families Columbidae, Laridae, and Accipitridae (2) Family sequence changes with Gruiformes and Pelecaniformes (3) Change of Spotted Dove scientific name to *Spilopelia chinensis* (4) Transfer of Cooper's Hawk and American Goshawk to the genus *Astur* (5) Restoration of Bluethroat to the genus *Luscinia* (6) Change of English names for species in the genus *Amazona* from "Parrot" to "Amazon"
Also, (1) The split of Herring Gull (*Larus argentatus*) into three species results in the new name American Herring Gull (*L. smithsonianus*) for our regular California birds, and the addition of Vega Gull (*L. vegae*) to the California state list PENDING ACCEPTANCE OF ONE OR MORE EXISTING RECORDS BY THE C.B.R.C. (2) The split of Warbling Vireo (*Vireo gilvus*) into two species results in the new name Western Warbling-Vireo (*V. swainsoni*) for our regular California birds, and the addition of Eastern Warbling-Vireo (*V. gilvus*) to the California state list PENDING ACCEPTANCE OF ONE OR MORE EXISTING RECORDS BY THE C.B.R.C.
Date: 8/11/25 8:49 am From: <tgmiko...> via groups.io <tgmiko...> Subject: Continuing 8/11/2025 Re: [CALBIRDS] Bar tailed Godwit Los Angeles 8/10/2025
Same area between stretch of beach immediately south of the Ballona Creek and the creek, itself. Find the crowd of birders and you will find the bird.
Thomas Geza Miko Claremont, LA County 909.241.3300
On Sun, Aug 10, 2025, 10:32 <tgmiko...> via groups.io <tgmiko= <gmail.com...> wrote:
> 33.966985,-118.447248 seen along Ballona Creek, but earlier this morning > it was in a large mixed flock on the nearby beach at 33.961218,-118.455940 > which is the first stretch of beach south of where the creek empties into > the ocean. Parking in this entire neighborhood is always in demand. Please > don't leave valuables in your car. This bird was found reported yesterday > by Larry Schmall. > What may have been the same bird was seen and photographed on Thursday. > That Bird was standing behind another bird so not all field marks were > visible in the photo. > > Thomas Geza Miko > Claremont, LA County > 909.241.3300 > > >
Date: 8/11/25 4:39 am From: <lehman.paul...> via groups.io <lehman.paul...> Subject: [CALBIRDS] San Diego pelagics: 2 Guadalupe Murrelets, 3 Manx, Masked/Nazca Booby, 30+ Townsend's Storm-Petrels
Back-to-back pelagic trips out of San Diego on 9 August and 10 August both recorded some good rarities and some locally high counts. On 9 Aug, a cooperative first-cycle Masked/Nazca Booby was in a plumage that is difficult to perhaps impossible to ID to species, and booby experts so far disagree over its identification; a Manx Shearwater was well seen some 20 miles offshore, and a high count of 30+ Townsend's Storm-Petrels was centered over the 30-Mile Bank, where also a locally high count of 12 Black-footed Albatrosses. On 10 Aug, two recognizably different Guadalupe Murrelets were three miles apart on the 30-Mile Bank, two more Manx Shearwaters were in roosting flocks of Back-venteds some six miles offshore, good counts of Townsend's Storm-Petrels and Black-footed Albatrosses continued, and there were about a dozen Craveri's Murrelets. As always, the Townsend's Storm-Petrels provided for an identification challenge, with also good numbers of darker-rumped and a few white-rumped Leach's present as well.
Good photos of many of these birds will be available starting later today or tomorrow via eBird. Any comments on the ID of the immature booby are welcomed.
Date: 8/10/25 10:32 am From: <tgmiko...> via groups.io <tgmiko...> Subject: [CALBIRDS] Bar tailed Godwit Los Angeles 8/10/2025
33.966985,-118.447248 seen along Ballona Creek, but earlier this morning it was in a large mixed flock on the nearby beach at 33.961218,-118.455940 which is the first stretch of beach south of where the creek empties into the ocean. Parking in this entire neighborhood is always in demand. Please don't leave valuables in your car. This bird was found reported yesterday by Larry Schmall. What may have been the same bird was seen and photographed on Thursday. That Bird was standing behind another bird so not all field marks were visible in the photo.
Thomas Geza Miko Claremont, LA County 909.241.3300
Date: 8/6/25 5:07 pm From: ed pandolfino via groups.io <erpfromca...> Subject: Re: [CALBIRDS] Pied-billed Grebe sinking behavior references?
A plug for BOW...
Anyone with even a passing interest in the biology, ecology, or behavior of birds should have a subscription to Birds of the World. At $49/year, a bargain at twice the price. https://birdsoftheworld.org/bow/subscribe Ed PandolfinoSacramento, CA
On Wednesday, August 6, 2025 at 04:09:23 PM PDT, Zac Denning via groups.io <zdenning1...> wrote:
Hi Joel,
Grebes have fine control over their buoyancy. They can sink at will by squeezing air out of their plumage (by flattening their feathers) as well as by expelling air from their internal air sacs. According to Birds of the World, the structure of their contour feathers includes coiled barbules that may serve to trap water and this may also give them a sleeker, more hydrodynamic profile, creating less turbulence as they glide through the water.Â
These adaptations allow them to float or sink to varying depths with ease. Unlike ducks, they don’t have to propel themselves at speed to keep from popping back up to the surface.
If you have a Birds Of The World subscription, this is covered for Pied-billed Grebe under Behavior > Locomotion > Swimming and Diving:Â https://birdsoftheworld.org/bow/species/pibgre/cur/behavior Zac DenningAlbany, CA
On Wed, Aug 6, 2025 at 11:51 AM wagtail1997 via groups.io <orcorba...> wrote:
Group,Mason Regional Park (Irvine, Orange County, CA) has a high density of Pied-billed Grebes right now. At least 3 of the 14 are showing quick sinking behavior. I've studied that for the last two weeks and come up with videos on the behavior, analysis of the sinking, a summary of possible mechanisms, ecology, and more. All that is missing is to actually find a scientific paper on the behavior, even after doing some online searches for such studies. Anyone have a reference that I can add to my show notes? The Grebe's legs and feet have a role in the late stages of the sinking. The head behavior is interesting and lags the submersion of the rest of the body.  I raise more questions than I can answer about the behavior.  https://youtu.be/v95FQgHPxq8 Â
Joel WeintraubIrvine Ca
Grebes have fine control over their buoyancy. They can sink at will by
squeezing air out of their plumage (by flattening their feathers) as well
as by expelling air from their internal air sacs. According to Birds of the
World, the structure of their contour feathers includes coiled barbules
that may serve to trap water and this may also give them a sleeker, more
hydrodynamic profile, creating less turbulence as they glide through the
water.
These adaptations allow them to float or sink to varying depths with ease.
Unlike ducks, they don’t have to propel themselves at speed to keep from
popping back up to the surface.
On Wed, Aug 6, 2025 at 11:51 AM wagtail1997 via groups.io <orcorba=
<cox.net...> wrote:
> *Group,*
> *Mason Regional Park (Irvine, Orange County, CA) has a high density of
> Pied-billed Grebes right now. At least 3 of the 14 are showing quick
> sinking behavior. I've studied that for the last two weeks and come up
> with videos on the behavior, analysis of the sinking, a summary of possible
> mechanisms, ecology, and more. All that is missing is to actually find a
> scientific paper on the behavior, even after doing some online searches for
> such studies. Anyone have a reference that I can add to my show notes?
> The Grebe's legs and feet have a role in the late stages of the sinking.
> The head behavior is interesting and lags the submersion of the rest of the
> body. I raise more questions than I can answer about the behavior. **https://youtu.be/v95FQgHPxq8 > <https://youtu.be/v95FQgHPxq8>* > Joel Weintraub
> Irvine Ca
>
>
>
Date: 8/6/25 11:51 am From: wagtail1997 via groups.io <orcorba...> Subject: [CALBIRDS] Pied-billed Grebe sinking behavior references?
Group,
Mason Regional Park (Irvine, Orange County, CA) has a high density of Pied-billed Grebes right now. At least 3 of the 14 are showing quick sinking behavior. I've studied that for the last two weeks and come up with videos on the behavior, analysis of the sinking, a summary of possible mechanisms, ecology, and more. All that is missing is to actually find a scientific paper on the behavior, even after doing some online searches for such studies. Anyone have a reference that I can add to my show notes? The Grebe's legs and feet have a role in the late stages of the sinking. The head behavior is interesting and lags the submersion of the rest of the body. I raise more questions than I can answer about the behavior. https://youtu.be/v95FQgHPxq8 Sent from my iPhone
Joel Weintraub
Irvine Ca
Date: 8/4/25 11:13 am From: Chuck & Lillian via groups.io <misclists...> Subject: Re: [CALBIRDS] Rufous/Allen's Hummingbird eBird mess
Good catch, Tristan!
What Tristan refers to is an excellent data-based example of the logical fallacy 'petitio principii,' aka 'petitioning the principle,' 'assuming the principal, 'circular reasoning' and formerly 'begging the question.' The last has recently degraded in common usage to mean "leaving unanswered the question.'
It boils down in logical syllogism construction to having your conclusion, or a critically important part of it, embedded, usually unnoticeably, within one or your premises. This is one of the more common logical fallacies, probably committed millions of times a day. It exists in some of the 'logical arguments for the existence of God' that have bounced around in western Christian writings for the last 500 years.
It probably happens in many, many other data-bases contexts, but I'm not sure I've heard of it before this.
Good birding! Chuck Almdale North Hills, Ca.
At 12:38 AM 8/4/2025, Tristan McKee via groups.io wrote: >The endless cycle of identifying birds by distribution and then >using that data to study bird distribution is one of the most >significant Achilles' heels in modern ornithology.
Date: 8/4/25 12:39 am From: Tristan McKee via groups.io <atmckee...> Subject: Re: [CALBIRDS] Rufous/Allen's Hummingbird eBird mess
Thank you, Paul and Don. This thought-provoking example underlines the very
important issue of how specific we should ideally be in our bird
identifications when geographic likelihood is a potential factor. Slash and
"sp." categories are not pretty or satisfying, but in many cases they allow
for more accurate comparative statements in biogeography. Refraining from
identifying subspecies except when physical traits warrant it would be a
reflection of the same choice.
The other day, I encountered about 165 Dark-eyed Juncos, mostly juveniles,
on Blake Mountain in eastern Humboldt County. Most were just seen as flocks
of small sparrows flying around with white outer tail feathers; let's say
that I saw 30 of them well enough to see that they were Oregon Juncos. I
think it is very common for observers to just record this as 165 Oregon
Juncos. Do Slate-colored or Cismontane juncos ever disperse far enough to
occur here in late summer? In retrospect, it would have been more helpful
for me to have recorded it as 30 Oregon and 135 Dark-eyed juncos, because
then if any Slate-coloreds did turn up (and as the observations built up
over the years), I'd be able to say something meaningful; for instance,
that one in 500 juncos in late July at Blake Mountain was a Slate-colored.
If I had been recording all juncos automatically as Oregons until I
happened to stumble on an occasional Slate-colored, then I'd have
absolutely no way of determining their relative abundance. As a parallel
example, one observer might pick through all the Californian Brant they see
and find that, say, one in 10,000 was a light-bellied Brant--which is a
meaningful statement--but if others just record all the Brant they see as
Black Brant by distribution, then we might look at ebird and see that
200,000 were reported as Black Brant and one was a light-bellied--which
does NOT tell us anything accurate about their relative abundance. Thus,
the optimal solution would be for the observers who did not critically
assess the Brant to record them only as Brant, preserving the usefulness of
the count made by the observer who did critically assess them. However, I
do realize that this is easier said than done, since people have variable
amounts of time and interest in sorting out their bird numbers and a lot of
bird lists to make!
The endless cycle of identifying birds by distribution and then using that
data to study bird distribution is one of the most significant Achilles'
heels in modern ornithology.
The general Selasphorus distribution patterns that Don described for
Monterey apply roughly to the rest of coastal Northern California, except
that at any given point moving north along the coast, there are
significantly fewer migrant Allen's originating from the north, whereas
there is still a large source population of Rufous in a generally
north-eastern direction.
Again we might conclude that the OPTIMAL data-collection strategy would be
to NEVER factor geographic likelihood into our Selasphorus identifications,
and for all California observers to record all Selasphorus except those
that are identified by physical traits as "sp.". This might allow for
meaningful statements to made about relative abundance: even if, e.g. ,
only 50 Allen's and five Rufous hummingbirds were identified out of a
thousand Selasphorus in a given county, we could still say that about 10%
were Rufous. However, Selasphorus are a particularly prickly special case
because of age/sex stratification, extreme difficulty of identification,
and the fact that many immature male Rufous Hummingbirds have green backs,
leading to the very real scenario that Allen's would rarely be identified
in the field at all if distribution was not taken into account.
I do not have an ideal solution to the statewide Selasphorus problem but
look forward to reading further assessments of it and strategies for
approaching it.
Thanks, everyone.
Tristan McKee
Arcata, CA
On Sun, Aug 3, 2025, 5:29 PM Don Roberson via groups.io <creagrus=
<montereybay.com...> wrote:
> Here in Monterey County, along the central California coast, we have the
> filter for Rufous Hummingbird set at zero from 16 May-30 July. This year
> we had 2 or 3 records of adult male Rufous in mid-to-late July, which is
> expected, and the only age/sex that we would typically approve in eBird
> without photos. Using banding information, we permit small numbers of
> first-arriving juv Rufous from 30 July-10 August, at which time juv Allen’s
> are essentially gone. The only overlap in juvs seems to be the first week
> of August. Only after 10 August do Rufous become the dominate Selasphorus.
> Of course, we do not have (yet) any ‘sedentarius’ Allen’s that complicate
> the picture in southern California. Here, it is nominate ‘sasin’ Allen’s
> that are a declining breeding populations between Feb-July. The migration
> of Rufous in August-September — mostly juvs — still seem to me in expected
> annual numbers along the coast.
>
> Thanks, Don
>
>
>
>
>
