Date: 3/28/26 3:47 pm From: Alexander Henry via groups.io <awhenry...> Subject: [EBB-Sightings] Early Migrant Wave March 28
Seems like we’re getting decent numbers of migrants already, Hammond’s Flycatchers, Chipping Sparrows, Nashville and Black-throated Gray Warblers, Black-headed Grosbeaks, etc. I guess they’re getting the same weather in western Mexico as we are here. Anyway don’t snooze, feels like things are a couple weeks ahead.
Date: 3/25/26 4:36 pm From: janet ellis via groups.io <jellis502003...> Subject: Re: [EBB-Sightings] eBird filters, and what to do when something is "rare"
Thank you.
On Wednesday, March 25, 2026, 3:17 PM, Kevin Schwartz via groups.io <kdschwartz...> wrote:
Thank you, Ethan for all you do for eBird! We appreciate you and this was a great write up about why things are getting flagged.
Kevin
| Kevin Schwartz, PhD
Principal Biologist/Wetland and Ecological Restoration Manager
ISA Certified Arborist (#WE-9541A)
ISA Qualified Tree Risk Assessor
CRAM Wetlands Official Practitioner
Olberding Environmental, Inc.
https://olberdingenvironmental.com/
On Wed, Mar 25, 2026, 11:22 AM Ethan Monk via groups.io <z.querula...> wrote:
And for those of you asking "WHY" – why do I have to include a description? We know the spring is early, why can’t you just accept it?
There are, I think, two good answers.
First, the philosophical/doctrinal one. If Species X arrives on the average date of March 15th, and this year the first arrivals are March 7th, even though by March 11th the species may seem “ho-hum” and clearly, they are here, historically the date is still quite significant, even though it may not be significant in the context of this specific season.
If that is not convincing, reason two is that data is always subject to revision. At any time now or in the future, an eBird reviewer can go into the database and update decisions that they think were wrong. We try not to do this frequently, because it is probably a good idea to trust the contemporaneous eBird reviewer, but that does not always happen for a number of reasons. The classic example are Golden-Plovers. In the early days of California birding, most birders thought (what is today known as) American Golden-Plovers were the common species in California, and Pacific Golden-Plovers were the rarest species. It was eventually realized that the exact opposite is the case, Pacifics are the commonest of the two species in California, and American the rarest, and a bunch of old records were revised to account for that mistaken understanding. If you were going back and reevaluating old records of American Golden-Plovers, would you be more likely to throw out records with or without field notes? I know my answer. That is not to say that in the future we will realize the early Western Flycatchers may be another species of Empidonax, for example, but rather a more stringent reviewer may decide to “clean-up” the data, or similar. And the records with no supporting field notes are more likely to be discarded, even if accurate, because… there is nothing there to support them.
Thanks.
Ethan M
On Wed, Mar 25, 2026 at 11:06 AM Ethan Monk <z.querula...> wrote:
Hi all,
Happy spring. If you use eBird, and would not mind reading for a second, that would be greatly appreciated.
As many people have noticed, it is an early spring, with many birds like Wilson's Warblers and Cassin's Vireos arriving well before they normally do. In Contra Costa County (and in many other counties, it is similar) the eBird filters are set to mark many species "rare" until several days after the all-time, record early spring arrival date. For example, the earliest historical arrivals for Cassin's Vireo in Contra Costa County history are right around March 21st-24th, so they are flagged as rare until March 27th. Early reports are more significant, and so are more deserving of scrutiny, and perhaps are more likely to be wrong (this is especially true in the age of Merlin, which uses some form of probability model when suggesting species identifications). This means that in early springs, like this one, active birders might be flagging the filter a lot, as large waves of spring migrants arriving earlier than typical will often flag as "rare."
So-- I am out eBirding, and I have found a species that flags as rare--what do I do? The "rare" designation is the system's way of telling you that it wants information to substantiate the sighting. How much information is needed is going to depend on the context, for example an aseasonal Western Tanager and a Spotted Redshank will produce the same response from the system ("rare"), but clearly require different levels of documentation. But, if something flags as rare, always always always some helpful information is needed. Writing something like "in pine tree" is only valuable in confirming that it was not a "pocket-click," and thus is not helpful really at all. In springs like this one, when many things are early, the early context can be taken into account, so not much information is needed at all, but again something is needed.
For many spring early arrivals, consider writing ~one sentence describing field marks you observed that led you to the ID. Otherwise, I will send you an email asking for more documentation, and that just creates more work for you and for me :) Even better if you can include something that indicates you understand why a species is rare, but this is not necessary. Going back to the Western Tanager example, say you see an early adult male Western Tanager tomorrow... what would be an ideal description? Well, it is a week or so early, about in line with many other early arriving species this spring. Something like "Early-- red head, bright yellow body, black wings" would probably get the job done. Even better, although absolutely not necessary, if you could write something like "this is an early spring... red head, bright..." That way people looking back on the eBird checklist in future years will have some additional context.
Thank you for considering.
Ethan Monk(a Contra Costa County eBird Reviewer)
Date: 3/25/26 3:17 pm From: Kevin Schwartz via groups.io <kdschwartz...> Subject: Re: [EBB-Sightings] eBird filters, and what to do when something is "rare"
Thank you, Ethan for all you do for eBird! We appreciate you and this was a
great write up about why things are getting flagged.
Kevin
*Kevin Schwartz, PhD*
*Principal Biologist/Wetland and Ecological Restoration Manager*
ISA Certified Arborist (#WE-9541A)
ISA Qualified Tree Risk Assessor
CRAM Wetlands Official Practitioner
Olberding Environmental, Inc.
https://olberdingenvironmental.com/
On Wed, Mar 25, 2026, 11:22 AM Ethan Monk via groups.io <z.querula=
<gmail.com...> wrote:
> And for those of you asking "WHY" – why do I have to include a
> description? We know the spring is early, why can’t you just accept it?
>
> There are, I think, two good answers.
>
> First, the philosophical/doctrinal one. If Species X arrives on the
> average date of March 15th, and this year the first arrivals are March 7th,
> even though by March 11th the species may seem “ho-hum” and clearly, they
> are here, historically the date is still quite significant, even though it
> may not be significant in the context of this specific season.
>
> If that is not convincing, reason two is that data is always subject to
> revision. At any time now or in the future, an eBird reviewer can go into
> the database and update decisions that they think were wrong. We try not to
> do this frequently, because it is probably a good idea to trust the
> contemporaneous eBird reviewer, but that does not always happen for a
> number of reasons. The classic example are Golden-Plovers. In the early
> days of California birding, most birders thought (what is today known as)
> American Golden-Plovers were the common species in California, and Pacific
> Golden-Plovers were the rarest species. It was eventually realized that the
> exact opposite is the case, Pacifics are the commonest of the two species
> in California, and American the rarest, and a bunch of old records were
> revised to account for that mistaken understanding. If you were going back
> and reevaluating old records of American Golden-Plovers, would you be more
> likely to throw out records with or without field notes? I know my answer.
> That is not to say that in the future we will realize the early Western
> Flycatchers may be another species of Empidonax, for example, but rather a
> more stringent reviewer may decide to “clean-up” the data, or similar. And
> the records with no supporting field notes are more likely to be discarded,
> even if accurate, because… there is nothing there to support them.
>
> Thanks.
>
> Ethan M
>
> On Wed, Mar 25, 2026 at 11:06 AM Ethan Monk <z.querula...> wrote:
>
>> Hi all,
>>
>> Happy spring. If you use eBird, and would not mind reading for a second,
>> that would be greatly appreciated.
>>
>> As many people have noticed, it is an early spring, with many birds like
>> Wilson's Warblers and Cassin's Vireos arriving well before they normally
>> do. In Contra Costa County (and in many other counties, it is similar) the
>> eBird filters are set to mark many species "rare" until several days after
>> the all-time, record early spring arrival date. For example, the earliest
>> historical arrivals for Cassin's Vireo in Contra Costa County history are
>> right around March 21st-24th, so they are flagged as rare until March 27th.
>> Early reports are more significant, and so are more deserving of scrutiny,
>> and perhaps are more likely to be wrong (this is especially true in the age
>> of Merlin, which uses some form of probability model when suggesting
>> species identifications). This means that in early springs, like this one,
>> active birders might be flagging the filter a lot, as large waves of spring
>> migrants arriving earlier than typical will often flag as "rare."
>>
>> So-- I am out eBirding, and I have found a species that flags as
>> rare--what do I do? The "rare" designation is the system's way of telling
>> you that it wants information to substantiate the sighting. How much
>> information is needed is going to depend on the context, for example an
>> aseasonal Western Tanager and a Spotted Redshank will produce the same
>> response from the system ("rare"), but clearly require different levels of
>> documentation. But, if something flags as rare, always always always some
>> helpful information is needed. Writing something like "in pine tree" is
>> only valuable in confirming that it was not a "pocket-click," and thus is
>> not helpful really at all. In springs like this one, when many things are
>> early, the early context can be taken into account, so not much information
>> is needed at all, but again something is needed.
>>
>> For many spring early arrivals, consider writing ~one sentence describing
>> field marks you observed that led you to the ID. Otherwise, I will send you
>> an email asking for more documentation, and that just creates more work for
>> you and for me :) Even better if you can include something that indicates
>> you understand why a species is rare, but this is not necessary. Going back
>> to the Western Tanager example, say you see an early adult male Western
>> Tanager tomorrow... what would be an ideal description? Well, it is a week
>> or so early, about in line with many other early arriving species this
>> spring. Something like "Early-- red head, bright yellow body, black wings"
>> would probably get the job done. Even better, although absolutely not
>> necessary, if you could write something like "this is an early spring...
>> red head, bright..." That way people looking back on the eBird checklist in
>> future years will have some additional context.
>>
>> Thank you for considering.
>>
>> Ethan Monk
>> (a Contra Costa County eBird Reviewer)
>>
>
>
>
>
Date: 3/25/26 11:22 am From: Ethan Monk via groups.io <z.querula...> Subject: Re: [EBB-Sightings] eBird filters, and what to do when something is "rare"
And for those of you asking "WHY" – why do I have to include a description?
We know the spring is early, why can’t you just accept it?
There are, I think, two good answers.
First, the philosophical/doctrinal one. If Species X arrives on the average
date of March 15th, and this year the first arrivals are March 7th, even
though by March 11th the species may seem “ho-hum” and clearly, they are
here, historically the date is still quite significant, even though it may
not be significant in the context of this specific season.
If that is not convincing, reason two is that data is always subject to
revision. At any time now or in the future, an eBird reviewer can go into
the database and update decisions that they think were wrong. We try not to
do this frequently, because it is probably a good idea to trust the
contemporaneous eBird reviewer, but that does not always happen for a
number of reasons. The classic example are Golden-Plovers. In the early
days of California birding, most birders thought (what is today known as)
American Golden-Plovers were the common species in California, and Pacific
Golden-Plovers were the rarest species. It was eventually realized that the
exact opposite is the case, Pacifics are the commonest of the two species
in California, and American the rarest, and a bunch of old records were
revised to account for that mistaken understanding. If you were going back
and reevaluating old records of American Golden-Plovers, would you be more
likely to throw out records with or without field notes? I know my answer.
That is not to say that in the future we will realize the early Western
Flycatchers may be another species of Empidonax, for example, but rather a
more stringent reviewer may decide to “clean-up” the data, or similar. And
the records with no supporting field notes are more likely to be discarded,
even if accurate, because… there is nothing there to support them.
Thanks.
Ethan M
On Wed, Mar 25, 2026 at 11:06 AM Ethan Monk <z.querula...> wrote:
> Hi all,
>
> Happy spring. If you use eBird, and would not mind reading for a second,
> that would be greatly appreciated.
>
> As many people have noticed, it is an early spring, with many birds like
> Wilson's Warblers and Cassin's Vireos arriving well before they normally
> do. In Contra Costa County (and in many other counties, it is similar) the
> eBird filters are set to mark many species "rare" until several days after
> the all-time, record early spring arrival date. For example, the earliest
> historical arrivals for Cassin's Vireo in Contra Costa County history are
> right around March 21st-24th, so they are flagged as rare until March 27th.
> Early reports are more significant, and so are more deserving of scrutiny,
> and perhaps are more likely to be wrong (this is especially true in the age
> of Merlin, which uses some form of probability model when suggesting
> species identifications). This means that in early springs, like this one,
> active birders might be flagging the filter a lot, as large waves of spring
> migrants arriving earlier than typical will often flag as "rare."
>
> So-- I am out eBirding, and I have found a species that flags as
> rare--what do I do? The "rare" designation is the system's way of telling
> you that it wants information to substantiate the sighting. How much
> information is needed is going to depend on the context, for example an
> aseasonal Western Tanager and a Spotted Redshank will produce the same
> response from the system ("rare"), but clearly require different levels of
> documentation. But, if something flags as rare, always always always some
> helpful information is needed. Writing something like "in pine tree" is
> only valuable in confirming that it was not a "pocket-click," and thus is
> not helpful really at all. In springs like this one, when many things are
> early, the early context can be taken into account, so not much information
> is needed at all, but again something is needed.
>
> For many spring early arrivals, consider writing ~one sentence describing
> field marks you observed that led you to the ID. Otherwise, I will send you
> an email asking for more documentation, and that just creates more work for
> you and for me :) Even better if you can include something that indicates
> you understand why a species is rare, but this is not necessary. Going back
> to the Western Tanager example, say you see an early adult male Western
> Tanager tomorrow... what would be an ideal description? Well, it is a week
> or so early, about in line with many other early arriving species this
> spring. Something like "Early-- red head, bright yellow body, black wings"
> would probably get the job done. Even better, although absolutely not
> necessary, if you could write something like "this is an early spring...
> red head, bright..." That way people looking back on the eBird checklist in
> future years will have some additional context.
>
> Thank you for considering.
>
> Ethan Monk
> (a Contra Costa County eBird Reviewer)
>
Date: 3/25/26 11:06 am From: Ethan Monk via groups.io <z.querula...> Subject: [EBB-Sightings] eBird filters, and what to do when something is "rare"
Hi all,
Happy spring. If you use eBird, and would not mind reading for a second, that would be greatly appreciated.
As many people have noticed, it is an early spring, with many birds like Wilson's Warblers and Cassin's Vireos arriving well before they normally do. In Contra Costa County (and in many other counties, it is similar) the eBird filters are set to mark many species "rare" until several days after the all-time, record early spring arrival date. For example, the earliest historical arrivals for Cassin's Vireo in Contra Costa County history are right around March 21st-24th, so they are flagged as rare until March 27th. Early reports are more significant, and so are more deserving of scrutiny, and perhaps are more likely to be wrong (this is especially true in the age of Merlin, which uses some form of probability model when suggesting species identifications). This means that in early springs, like this one, active birders might be flagging the filter a lot, as large waves of spring migrants arriving earlier than typical will often flag as "rare."
So-- I am out eBirding, and I have found a species that flags as rare--what do I do? The "rare" designation is the system's way of telling you that it wants information to substantiate the sighting. How much information is needed is going to depend on the context, for example an aseasonal Western Tanager and a Spotted Redshank will produce the same response from the system ("rare"), but clearly require different levels of documentation. But, if something flags as rare, always always always some helpful information is needed. Writing something like "in pine tree" is only valuable in confirming that it was not a "pocket-click," and thus is not helpful really at all. In springs like this one, when many things are early, the early context can be taken into account, so not much information is needed at all, but again something is needed.
For many spring early arrivals, consider writing ~one sentence describing field marks you observed that led you to the ID. Otherwise, I will send you an email asking for more documentation, and that just creates more work for you and for me :) Even better if you can include something that indicates you understand why a species is rare, but this is not necessary. Going back to the Western Tanager example, say you see an early adult male Western Tanager tomorrow... what would be an ideal description? Well, it is a week or so early, about in line with many other early arriving species this spring. Something like "Early-- red head, bright yellow body, black wings" would probably get the job done. Even better, although absolutely not necessary, if you could write something like "this is an early spring... red head, bright..." That way people looking back on the eBird checklist in future years will have some additional context.
Date: 3/20/26 8:57 am From: Cathy Bleier via groups.io <csbleier...> Subject: [EBB-Sightings] Richmond shoreline toxics tour tomorrow (3/21) and next Saturday
Date: 3/10/26 11:06 pm From: Lee Friedman via groups.io <lfried6...> Subject: [EBB-Sightings] An Unusual Sighting of Breeding Bird behaviors
Like many of us, I am contributing to the California Atlas Project of breeding birds. I find that I am noticing and appreciating bird behaviors—sightings—that I might have overlooked earlier. Yesterday I observed at Lake Anza a pair of Dark-eyed Juncos displaying two breeding phases simultaneously: copulation and gathering nest materials. The male happened to be banded as well (although numbers not legible). These can be seen in the linked photograph:
Afterwards, the female continued transporting her beak full of nesting material with no apparent dropage. Taken in block Richmond SE at Lake Anza in Tilden Regional Park, CA on March 9, 2026. (Note to Atlasers: Lake Anza is divided into two different blocks by a north-south line that goes down the middle of the Lake.)
Date: 3/10/26 12:24 pm From: Peter Pyle via groups.io <ppyle...> Subject: [EBB-Sightings] Noyo Pelagics 2026 dates - buttons now working + N Cal Pelagic Trips
Greetings Bay Area on this nice spring day (for upwelling and the ocean, at least...).
Our buttons for full-day Noyo Pelagics trips are now ready for sign-ups for the previously mentioned dates:
We had a fine half-day trip on March 1st including an unexpected Scripps's Murrelet and early Humpback Whales (see report at the link above). We will be offering more half-day trips on a short-notice (7-10 day) basis as good-weather windows approach; if you may be interested in these you can monitor Mendobirds or sign up for the Mendo-Pelagics io group serve (<https://groups.io/g/Mendocino-Pelagics>). See https://noyopelagics.com/about-our-trips/ for more on our half-day, full-day, and educational trips.
We have attempted this year to organize some back-to-back trips along the NorCal coast, or with a day or two in between. Unfortunately at this time there are no trips planned to Cordell Bank since the Bodega Bay skipper sold his boat this winter. Hopefully something will work out there soon. For now, we have some back-to-back or even week-long opportunities for multiple trips from Sausalito, Fort Bragg, and Eureka. I have listed these below (with sign-up information below the dates); if you know of ABA folks or others around the country that may be interested, please pass this along. Logan has also set up a Google calendar which he will finalize tonight at:
Hope to see you up here for a trip, or two, or more!
Good birding, Peter
Northern California Pelagic Trip dates:
Fort Bragg (Noyo Pelagics) - April 4th (Saturday) Sausalito - SF waters trip April 18th (Saturday) - currently full but see below* Fort Bragg (Noyo Pelagics) - April 26th (Sunday) Eureka Rob Fowler - May 2nd (Saturday) Fort Bragg (Noyo Pelagics) - May 9th (Saturday) - Eureka RRAS - May 10th (Sunday) Fort Bragg (Noyo Pelagics) - May 30th (Saturday) Eureka Rob Fowler - June 13th (Saturday) Sausalito Al's Adventures - Farallon Islands trips weekly June 13 - August 8 Fort Bragg (Noyo Pelagics) - June 14th (Sunday) Eureka RRAS - June 20th (Saturday) Fort Bragg (Noyo Pelagics) - June 26th (Friday) Eureka RRAS - July 18th (Saturday) Fort Bragg (Noyo Pelagics) - July 20th (Monday) Eureka Rob Fowler - July 25th (Saturday) Fort Bragg (Noyo Pelagics) - August 3rd (Monday) Eureka RRAS - August 15th (Saturday) Eureka Rob Fowler - August 29th (Saturday) Fort Bragg (Noyo Pelagics) - August 30th (Sunday) Eureka RRAS - September 5th (Saturday) Sausalito Al's Adventures - SF trip September 13th (Sunday) Eureka Rob Fowler - September 19th (Saturday) Eureka Rob Fowler - October 3rd (Saturday) Eureka RRAS - October 10th (Saturday) Fort Bragg (Noyo Pelagics) - October 17th (Saturday) Eureka Rob Fowler - October 24th (Saturday) Fort Bragg (Noyo Pelagics) - November 1st (Sunday) Eureka Rob Fowler - November 14th (Saturday) Eureka RRAS - November 21st (Saturday) Eureka Rob Fowler - December 5th (Saturday)
*The 4/18 trip from Sausalito is full but there are still spaces left on the back-up date (4/21). Contact Logan Kahle <logan...> if interested in this back-up trip.
On 12/19/2025 7:36 AM, Peter Pyle wrote: > Greetings Bay Area birders - > > We have finalized our dates for full-day Noyo Pelagics trips (below). > > We are running 2-3 more trips in April-July due to great success last > year with albatrosses (up to 1000 Black-foots, many Laysans, and three > separate Short-taileds) and Pterodroma petrels (6+ Hawaiians, 90+ > Murphys, 15 Cook's, and one likely Herald) during these months. I am > also working with the organizers of pelagic trips from Bodega Bay and > Eureka to try and schedule some "runs" of back-to-back-to-back trips > over 3-5 days moving up or down the coast. I have suggested the four > dates below for these but they may occur at other times. > > Our payment system for these trips at https://noyopelagics.com/ is not > yet set up. I'll send an announcement when it is, hopefully by mid > January. We wanted to get the dates out now so birders can start > thinking about joining us on one or more trips. Hope to see you at > Noyo in '26! > > Peter > > April 4th (Saturday) (Easter weekend) > April 26th (Sunday) > May 9th (Saturday) - coordinate with Humboldt and Bodega? > May 30th (Saturday) > June 14th (Sunday) - coordinate with Humboldt and Bodega? > June 26th (Friday) > July 20th (Monday) - coordinate with Humboldt and Bodega? > August 3rd (Monday) > August 30th (Sunday) - coordinate with Humboldt and Bodega? > October 17th (Saturday) > November 1st (Sunday) >
Date: 3/9/26 9:30 am From: Ethan Monk via groups.io <z.querula...> Subject: [EBB-Sightings] [CALBIRDS] California Bird Atlas Update + March 19 Town Hall
Date: 3/7/26 1:00 pm From: Claude Lyneis via groups.io <cmlyneis...> Subject: [EBB-Sightings] Black-skimmer at Stege Marsh
Friday, on a clear warm afternoon the Black-skimmers (about 10) were out on the mud just west of the bay trail along Stege Marsh. It was another chance to get some photographs. This was the first time I got a photo showing the fine detail of the bill. Also as I was leaving, there was a young Peregrine Falcon on the power line east of the bay trail. I saw one there about 1 month ago, but this seemed to be a different falcon.
At approximately 2:30 on March 6 a mature Bald Eagle was soaring above the water. I also saw an Osprey flying east of the water. The usual suspects were also in evidence, including a pair of Red-tailed Hawks.
Date: 3/3/26 10:24 am From: Sam Zuckerman via groups.io <samzuckerman...> Subject: [EBB-Sightings] Gulls Extravaganza at Pt San Pablo
Saturday morning I birded the Point San Pablo marina on a falling tide. Gulls descended on the breakwater, including Glaucous-winged, American Herring, and Thayer's in addition to our more-common Western and California. Most of the gulls were first or second winter, some transitioning to breeding plumage, presenting difficult identification challenges. And that doesn't even take into consideration hybridization! I took alot of photos but gave up identification in most cases. For anyone who enjoys ID challenges -- or is simply a birder with a masochistic streak -- the checklist is here (https://ebird.org/checklist/S304715477) with a bunch of photos posted under gull sp. By all means, let me know if you think you know what some of these gulls are.
