Date: 4/13/26 5:43 pm From: Ronald- Thorn via groups.io <Tronthorn...> Subject: [pen-bird] Passerine migrants along the bayside
Migration along the bayside has been pretty slow and not much in the way of variety. Orange-crowned Warblers in the last week have increased in numbers. Saturday the first Wilson'sWarblers were arriving. This morning looked good for a drop-in of migrants, as during the night there were showers. At Coyote Point County Park along the Bay Trail, there were aWestern Flycatcher, Warbling Vireo, Cassin's Vireo, ( 3 ) Orange-crowned Warblers, ( 14 ) Yellow-rumped Warblers and ( 3 ) Wilson's Warblers. At Sem Lane in Belmont, there wasa Hammond's Flycatcher along the public access trail, long primary extension making tail appear short, gray head, olive-gray back, light gray underparts, white eye-ring, short andnarrow bill, flicking tail and wings, giving "peek" call notes. A Chipping Sparrow was with Golden and White-crowned Sparrows.
Ron Thorn
Date: 4/9/26 4:54 pm From: maliadances via groups.io <maliadances...> Subject: [pen-bird] California Breeding Bird Atlas statistics for San Mateo County and joining the project
Dear San Mateo County Birders,
As of yesterday, 4/8/26 these are some of the latest San Mateo County statistics reflecting the efforts of those participating in the California Bird Atlas Project.
230 Atlasers are participating in San Mateo County
2,211 checklists have been submitted to the project so far in our county
58 out of 66 Atlas blocks have received some coverage
47 species have been assigned “confirmed” breeding codes
*Very important!* I have been seeing checklists which are full of breeding codes. However, many of those checklists are not included in the Breeding Bird Atlas Project because the creator of the checklist has not joined California Bird Atlas Project. *If your intention is to have your coded checklists count, you must join the project in order for your checklists to be included in the project.* *If you have not yet joined the project,* you can do so *here* ( https://ebird.org/atlascalifornia/home ). Also be sure to read and become familiar with the correct use of the Breeding Codes https://ebird.org/atlascalifornia/about/breeding-codes
I’m very much enjoying and observing the birds during this delightful time of year!
Date: 4/9/26 3:40 pm From: maliadances via groups.io <maliadances...> Subject: [pen-bird] Fw: [CALBIRDS] California Bird Atlas Newsletter + April 16 Town Hall
[Edited Message Follows]
Hi San Mateo County Birders,
Here is the latest California BIrd Atlas Newsletter and info for the next Town Hall on April 16th
Malia
----- Forwarded Message -----
*From:* Van Pierszalowski via groups.io <van...>
*To:* "<calbirds...>" <calbirds...>
*Sent:* Monday, April 6, 2026 at 09:14:44 AM PDT
*Subject:* [CALBIRDS] California Bird Atlas Newsletter + April 16 Town Hall
Birders,
Thank you to everyone contributing to the California Bird Atlas. The latest edition of *The Atlas Dispatc h* is now live. Click *here ( https://ebird.org/atlascalifornia/news/atlas-dispatch-march-2026 )* for a full update, including Atlas-first breeding records, field highlights from across the state, and incredible photos.
We continue to be blown away by the level of engagement statewide. As of today, 66,642 Atlas checklists have been submitted across 5,131 blocks, spanning all 58 counties. 3,196 atlasers have contributed to the project, and we’re still in the first spring of a five-year Atlas period!
California Bird Atlas is an independent 501(c)(3), and donations can be made *here ( https://donorbox.org/california-bird-atlas )*. Your support helps us grow the team, expand coverage, and continue building this incredible momentum statewide. We are deeply grateful :)
Date: 4/9/26 3:37 pm From: maliadances via groups.io <maliadances...> Subject: [pen-bird] Fw: [CALBIRDS] California Bird Atlas Newsletter + April 16 Town Hall
Hi San Mateo County Birders,Here is the latest California BIrd Atlas Newsletter and info for the next Town Hall on April 18thMalia
----- Forwarded Message ----- From: Van Pierszalowski via groups.io <van...>To: "<calbirds...>" <calbirds...>Sent: Monday, April 6, 2026 at 09:14:44 AM PDTSubject: [CALBIRDS] California Bird Atlas Newsletter + April 16 Town Hall
Birders, Thank you to everyone contributing to the California Bird Atlas. The latest edition of The Atlas Dispatch is now live. Click here for a full update, including Atlas-first breeding records, field highlights from across the state, and incredible photos. We continue to be blown away by the level of engagement statewide. As of today, 66,642 Atlas checklists have been submitted across 5,131 blocks, spanning all 58 counties. 3,196 atlasers have contributed to the project, and we’re still in the first spring of a five-year Atlas period! If you haven’t joined the eBird Atlas project yet, you can do so here. We also hosted our first CBA Town Hall on March 19. A recording is available on our YouTube channel here. Our next Town Hall is April 16. We’ll share project updates, take questions, and feature Megan Jankowski (CBA Review Coordinator) presenting on how to find breeding birds. Register for the Zoom here. Submit questions here. California Bird Atlas is an independent 501(c)(3), and donations can be made here. Your support helps us grow the team, expand coverage, and continue building this incredible momentum statewide. We are deeply grateful :) Thanks, all - we’re just getting started! Happy Atlasing,Van Pierszalowski
Executive DirectorCalifornia Bird Atlas <van...> Angeles, CA
Date: 4/7/26 6:00 pm From: Barbara Kossy via groups.io <bkossy...> Subject: [pen-bird] Fitzgerald Marine Reserve near the parking lot
During a low to middling low tide the reef was a great spot for a bit of birding. There were about 100 elegant terns on the reef, resting and occasionally taking to the sky. At least 10 Caspian terns were on the edges of the group, two were seen mating. I counted 7 Black Oystercatchers, 1 female Red-breasted Merganser, lots of Western Gulls, and Short-billed gull. (I think. Gray legs, black band on bill.) Brow Pelicans cruised overhead. A few Ravens walked the reef and occasionally harassed the terns. Nearby the harbor seals were hauling out and the tide came up. A few were pregnant, there were a couple of young pups, and some seals were cavorting in the protected waters. As the tide came up the terns moved onto the sand.
A Moss Beach note: Red -shouldered hawks are in the area carrying prey, I assume to a nest. I don't know where the nest is, but it's probably not far from the old nest that was near the bridge over the creek.
Date: 4/7/26 4:50 pm From: San Mateo County Bird Alliance via groups.io <office...> Subject: [pen-bird] Thurs. April 9 - CA Condors
*Thursday, April 9 Monthly Meeting– Zoom*
*Northern California Condor Restoration Program, Chris West*
Chris West is the Northern California Condor Program Manager and Yurok Wildlife Department Senior Biologist. He began working with California condor as an intern at Ventana Wildlife Society in 1999 after graduating from the University of California at Santa Cruz. His passion for condors led to his master’s research at Humboldt State University investigating condor vigilance behavior while feeding. He began employment with the Yurok Tribe in 2008, working to set up the first reintroduction site in the Pacific Northwest, and is now the Manager of the Northern California Condor Restoration Program, a joint Program between the Yurok Tribe and the National Park Service.
Date: 4/3/26 12:34 pm From: Ronald- Thorn via groups.io <Tronthorn...> Subject: [pen-bird] Pigeon Point seawatch 4/2
Yesterday, I did a seawatch from Pigeon Point. Conditions for viewing was mostly clear out to the horizon and a brisk northwest at 10-15 mph. Here is a list of what was noted in thetwo hour seawatch. Low number of ( 54 ) Surf Scoters. ( 5 ) Whimbrels, ( 18 ) Surfbirds, constant movement of Common Murres with ( 7,100 ) and still coming by when I departed, ( 3 ) Pigeon Guillemots, ( 5 ) Rhinoceros Auklets, ( 3 ) Elegant Terns. I was surprised in the number of ( 56 ) 1st cycle Heerman's Gulls moving north, as I may only note one or twoat this time of the year, ( 68 ) Western Gulls, ( 120 ) California Gulls, ( 1 ) Glaucous-winged Gull, ( 123 ) Common Loons, all in alternate plumage were on the move, the numberof Red-throated and Pacific Loons very low for this time of the year, ( 28 ) Red-throated Loons, ( 9 ) were in alternate plumage, ( 1 ) Pacific Loon, the first I have noted in alternateplumage, ( 6 ) Western Grebes. Sooty Shearwaters have arrived, ( 204 ) were headed south three-quarters the way out to the horizon, arrivals off of Pt. Pinos, Monterey Countywere ( 500 ) Sooty Shearwaters on Mar. 31. ( 160 ) Brown Pelicans, ( 70 ) Brandt's Cormorants, ( 2 ) Pelagic Cormorants and a Great Blue Heron flying over the water.
Ron Thorn
Date: 4/2/26 12:11 pm From: Christopher Hayward via groups.io <p_t_nymph...> Subject: [pen-bird] Bald Eagle and Rufous Hummingbird, Half Moon Bay Yard, 4/2/26
Hi All,
This morning while checking Hummingbirds in our yard it was exciting to have a Bald Eagle soaring high overhead, only the second one I've seen from the yard and a first for Malia.
On 3/28 I had a good but brief look at an all reddish backed Hummingbird feeding in our Bottlebrush, it was chased off before I could grab my camera. This morning I had what appears to be a different Male Rufous Hummingbird perched with it's back to me before again being chased off by our very territorial male Anna's, but I did manage a couple of photos this time. It looks to be a different bird from a few days ago, this individual has some green flecks on the head and back, the Hummer a few days ago was completely red backed, worth watching for Male Rufous Hummingbirds along the coast right now, we have had numerous sightings over the years in the yard here from late March into April.
Some photos on our checklist, link below.
Date: 3/31/26 5:33 pm From: Ronald- Thorn via groups.io <Tronthorn...> Subject: [pen-bird] Palm Warbler in Belmont
I checked Redwood Shores to see if any passerine migrants had come in after the rain passed through. No shortage of Yellow-rumped Warblers! The public access trail at the endof Sem Lane in Belmont, there was a Palm Warbler. It flew out of the area of the basketball court over to the other side of the creek. It perched in a dried clump of Sweet Fennel. Ithas pretty much come along in it's prealternate molt showing a chestnut crown and light streaking on the underparts. A tinge of yellow on the throat and breast. Yes, constant movingof the tail up and down! There were ( 157 ) Black Skimmers in Redwood Shores. Radio Road ( 130 ) and ( 27 ) at Preserve Park during high tide.
Ron Thorn
Date: 3/30/26 12:56 am From: Barbara Kossy via groups.io <bkossy...> Subject: Re: [pen-bird] Bald eagle
That's great!
Barbara Kossy
Moss Beach, California
Mobile: 650-430-1094
On Mon, Mar 30, 2026, 7:44 AM Katherine Raspet <walkmonkey...> wrote:
> There’s been quite a few sightings over the last few weeks, particularly
> around Fitzgerald Marine Reserve.
>
> -Cricket
>
> On Mar 29, 2026, at 10:37 PM, Barbara Kossy via groups.io <bkossy=
> <coastside.net...> wrote:
>
>
> My husband said he saw a bald eagle over southern Moss Beach.
> Did anyone see it.
> He's seen many, so i trust his identification.
> He included this photo in his message to me.
> Barbara Kossy
>
> <1000054315.jpg>
>
>
>
> Barbara Kossy
> Moss Beach, California
> Mobile: 650-430-1094
>
>
>
>
>
Date: 3/29/26 10:37 pm From: Barbara Kossy via groups.io <bkossy...> Subject: [pen-bird] Bald eagle
My husband said he saw a bald eagle over southern Moss Beach. Did anyone see it. He's seen many, so i trust his identification. He included this photo in his message to me. Barbara Kossy
Barbara Kossy Moss Beach, California Mobile: 650-430-1094
Date: 3/29/26 6:26 pm From: Ronald- Thorn via groups.io <Tronthorn...> Subject: [pen-bird] Sightings the past week
An adult male Eurasian Wigeon was with American Wigeon on the Ravenswood Salt Pond R1/R 2, 3/21-24. There were also ( 11 ) Lesser Yellowlegs among Greater Yellowlegs at the P.G.E. boardwalk. ( 14 ) Savannah Sparrows in a weed patch were most likely made up of migrants. Access is from the frontage road. In Redwood Shores, an immature male Eurasian x American Wigeon hybrid I noted on 1/5 at the end of Canvasback Way was in the marsh behind the dog park along Radio Road 3/22-25. There has not been much ofpasserine migration along the bayside. An early Nashville Warbler was at the Redwood Shores Library on 3/24. There has been a number of Orange-crowned Warblers passingthrough Redwood Shores. On 3/27, Leonie and I had a gray-headed one along Radio Road.
Ron Thorn, Leonie Batkin
Date: 3/26/26 12:42 pm From: Ronald- Thorn via groups.io <Tronthorn...> Subject: [pen-bird] Pigeon Point seawatch 3/25
Yesterday morning, I did a seawatch from Pigeon Point. Chris Hayward arriving at the end of the seawach contributed adding more Brant to the count. Although the conditions weregood with a brisk northwest wind and clear visibility out to the horizon, no tubenoses were noted. Sooty Shearwaters should be arriving soon. Noted during the three hour seawatch.Brant were passing behind the rock off of the lighthouse, numbers that I have not noted in quite awhile were ( 1,013 ) Brant. Other northbound birds were ( 956 ) Surf Scoters,( 4 ) Black Scoters, ( 13 ) Red-breasted Mergansers, ( 102 ) Red-throated Loons, the first I have noted in alternate plumage were ( 14 ) Common Loons, ( 1 ) Pacific Loon, ( 27 )Whimbrels, ( 1 ) Long-billed Curlew, ( 1 ) Semipalmated Plover. I had already noted ( 107 ) Sanderlings, when a steady stream passed behind the rock, it was difficult get a good count. There were between ( 550-600 ) Sanderlings, I have never had that experience before from years seawatching at the point! The first Bonaparte's Gulls noted were ( 24 ), ( 6 ) Short-billed Gulls, casual visitor on the coast ( 2 ) Ring-billed Gulls, ( 82 ) California Gulls, ( 2 ) Herring Gulls, ( 1 ) Iceland ( Thayer's ) Gull, ( 73 ) Western Gulls, ( 1 ) Heerman'sGull, ( 5 ) Caspian Terns, ( 21 ) Elegant Terns, ( 1,600 ) Common Murres, ( 18 ) Pigeon Guillemots and ( 4 ) Rhinoceros Auklets.
Ron Thorn
Date: 3/25/26 5:15 pm From: Al Eisner via groups.io <eisner...> Subject: Re: [pen-bird] Merlin Audio recordings - Rufous and Allen's Hummingbirds - please read.
On Wed, 25 Mar 2026, <johndebell...> via groups.io wrote:
> Thanks Malia! > Merlin is a wonderful tool, and I use it daily to enhance my bird-walking experience, and I have often learned somewhat obscure bird calls or songs from it. But it makes many mistakes, and not only likely "close-calls" as you've described. It thinks I am an oak titmouse, almost half of the time that I am imitating a chickadee, and while "pishing" at other times, occasionally thinks I'm a barn owl. I've observed it identifying Stellar's jays as red-tailed hawks when they do their frequent imitations, and I've catched it identifying a small barking dog as a Canada goose. I would never assume that it has reliably ID'd any call or song that cannot be independently verified, and believe it should never be depended upon to do so, but it is still an extremely useful tool that I find both enjoyable and helpful in the field.
Hi, John:
One test is whehher small birds you ar trying to pish into viee think you are a Barn Owl. That could br a problem. :)
Date: 3/25/26 3:41 pm From: Christopher Hayward via groups.io <p_t_nymph...> Subject: [pen-bird] Lesser Black-backed Gull, Gazos Creek State Beach, 3/25/26
Hi All,
Today around noon there was a Lesser Black-backed Gull in the gull flock at Gazos Creek State Beach, the gull flock was not visible from the parking lot but just north around the point where the creek enters the ocean. The flock was only 100 gulls or so making it fairly easy to pick out the Lesser Black-backed.
Also worth noting that at Pigeon Point earlier there were big numbers of Brant Geese flying north in large groups, I noted perhaps 200 or more in a casual sea watch.
Photos of the Lesser Black-backed Gull link below.
Merlin often IDs the single very high pitched single note call robins
sometimes give as cedar waxwing, fwiw. I’ve had it identify people talking
in the distance as GHOW.
On Wed, Mar 25, 2026 at 11:48 Alvaro Jaramillo via groups.io <chucao=
<coastside.net...> wrote:
> Jan
>
>
>
> Cedar Waxwings often just fly over, calling. At times these can be daily
> along the coast in Half Moon Bay, and common. Yet you seldom see them
> perching, just flying over. I wonder if the instrument was detecting these
> fly overs? As well, the flight calls are high pitched and many folks can’t
> hear them, but the machine might? Just throwing out thoughts.
>
>
>
> Alvaro
>
>
>
> Alvaro Jaramillo
>
> <alvaro...>
>
> www.alvarosadventures.com
>
>
>
> *From:* <peninsula-birding...> <peninsula-birding...> *On
> Behalf Of *cossypha via groups.io
> *Sent:* Wednesday, March 25, 2026 1:42 PM
> *To:* <nlgoodman...>
> *Cc:* <peninsula-birding...>
> *Subject:* Re: [pen-bird] Merlin Audio recordings - Rufous and Allen's
> Hummingbirds - please read.
>
>
>
> Most of these audio id programs use machine learning algorithms for ID;
> they do not know the full range of any species' vocalizations let alone any
> population differences or mimicry. They learn by sorting a large number of
> samples into the most likely bins. I recently tested a device at my home,
> called BirdWeather, that does similar things; at first it was wildly
> inaccurate, giving me species that would trigger a lot of excitement if
> they were found in this area, but over the course of a week it improved,
> zeroing in on the common species in my yard. However it persistently told
> me there were Cedar Waxwings present, which do come through once in a while
> but were definitely not present that week. It never detected Bewick's Wren
> although they are always here; possibly because of the complexity and
> individual variation of their song? Don't know about Merlin per se but it
> would have the same issues although possibly a better performance.
>
>
>
> Bottom line; you need to verify these audio ids, particularly in a new
> location or in the case of migrants moving through.
>
>
>
> Jan Leonard
>
>
>
> On Wed, Mar 25, 2026 at 9:35 AM Naomi Goodman via groups.io <nlgoodman=
> <hotmail.com...> wrote:
>
> I had the same experience at Burleigh-Murray earlier in March. I've
> attached a recording of a hummer that Merlin IDd as Rufous. It had a mostly
> rufous back with a small green patch. It doesn't surprise me that Merlin
> can't distinguish these two species calls. The sonograms of the
> "Dzeet-Chippety" calls in Peterson's Guide look very similar. If the calls
> are variable, it might be a tall order to improve the ID. What
> characteristics do you use to distinguish between the calls?
>
>
>
>
Date: 3/25/26 12:19 pm From: David Suddjian via groups.io <dsuddjian...> Subject: Re: [pen-bird] Merlin Audio recordings - Rufous and Allen's Hummingbirds - please read.
A valuable perspective when using Merlin is not to consider that it is
identifying anything, but that it is just suggesting an ID which needs to
be verified. So, instead of "Merlin says . . ." it is "Merlin suggests . .
."
David Suddjian
On Wed, Mar 25, 2026 at 10:41 AM <johndebell...> via groups.io
<johndebell...> wrote:
> Thanks Malia!
> Merlin is a wonderful tool, and I use it daily to enhance my
> bird-walking experience, and I have often learned somewhat obscure bird
> calls or songs from it. But it makes many mistakes, and not only likely
> "close-calls" as you've described. It thinks I am an oak titmouse, almost
> half of the time that I am imitating a chickadee, and while "pishing" at
> other times, occasionally thinks I'm a barn owl. I've observed it
> identifying Stellar's jays as red-tailed hawks when they do their frequent
> imitations, and I've catched it identifying a small barking dog as a Canada
> goose. I would never assume that it has reliably ID'd any call or song
> that cannot be independently verified, and believe it should never be
> depended upon to do so, but it is still an extremely useful tool that I
> find both enjoyable and helpful in the field.
>
>
>
Date: 3/25/26 10:48 am From: Alvaro Jaramillo via groups.io <chucao...> Subject: Re: [pen-bird] Merlin Audio recordings - Rufous and Allen's Hummingbirds - please read.
Jan
Cedar Waxwings often just fly over, calling. At times these can be daily along the coast in Half Moon Bay, and common. Yet you seldom see them perching, just flying over. I wonder if the instrument was detecting these fly overs? As well, the flight calls are high pitched and many folks can’t hear them, but the machine might? Just throwing out thoughts.
From: <peninsula-birding...> <peninsula-birding...> On Behalf Of cossypha via groups.io
Sent: Wednesday, March 25, 2026 1:42 PM
To: <nlgoodman...>
Cc: <peninsula-birding...>
Subject: Re: [pen-bird] Merlin Audio recordings - Rufous and Allen's Hummingbirds - please read.
Most of these audio id programs use machine learning algorithms for ID; they do not know the full range of any species' vocalizations let alone any population differences or mimicry. They learn by sorting a large number of samples into the most likely bins. I recently tested a device at my home, called BirdWeather, that does similar things; at first it was wildly inaccurate, giving me species that would trigger a lot of excitement if they were found in this area, but over the course of a week it improved, zeroing in on the common species in my yard. However it persistently told me there were Cedar Waxwings present, which do come through once in a while but were definitely not present that week. It never detected Bewick's Wren although they are always here; possibly because of the complexity and individual variation of their song? Don't know about Merlin per se but it would have the same issues although possibly a better performance.
Bottom line; you need to verify these audio ids, particularly in a new location or in the case of migrants moving through.
I had the same experience at Burleigh-Murray earlier in March. I've attached a recording of a hummer that Merlin IDd as Rufous. It had a mostly rufous back with a small green patch. It doesn't surprise me that Merlin can't distinguish these two species calls. The sonograms of the "Dzeet-Chippety" calls in Peterson's Guide look very similar. If the calls are variable, it might be a tall order to improve the ID. What characteristics do you use to distinguish between the calls?
Date: 3/25/26 10:41 am From: cossypha via groups.io <leonard.janetl...> Subject: Re: [pen-bird] Merlin Audio recordings - Rufous and Allen's Hummingbirds - please read.
Most of these audio id programs use machine learning algorithms for ID;
they do not know the full range of any species' vocalizations let alone any
population differences or mimicry. They learn by sorting a large number of
samples into the most likely bins. I recently tested a device at my home,
called BirdWeather, that does similar things; at first it was wildly
inaccurate, giving me species that would trigger a lot of excitement if
they were found in this area, but over the course of a week it improved,
zeroing in on the common species in my yard. However it persistently told
me there were Cedar Waxwings present, which do come through once in a while
but were definitely not present that week. It never detected Bewick's Wren
although they are always here; possibly because of the complexity and
individual variation of their song? Don't know about Merlin per se but it
would have the same issues although possibly a better performance.
Bottom line; you need to verify these audio ids, particularly in a new
location or in the case of migrants moving through.
Jan Leonard
On Wed, Mar 25, 2026 at 9:35 AM Naomi Goodman via groups.io <nlgoodman=
<hotmail.com...> wrote:
> I had the same experience at Burleigh-Murray earlier in March. I've
> attached a recording of a hummer that Merlin IDd as Rufous. It had a mostly
> rufous back with a small green patch. It doesn't surprise me that Merlin
> can't distinguish these two species calls. The sonograms of the
> "Dzeet-Chippety" calls in Peterson's Guide look very similar. If the calls
> are variable, it might be a tall order to improve the ID. What
> characteristics do you use to distinguish between the calls?
>
>
>
Date: 3/25/26 9:41 am From: <johndebell...> via groups.io <johndebell...> Subject: Re: [pen-bird] Merlin Audio recordings - Rufous and Allen's Hummingbirds - please read.
Thanks Malia! Merlin is a wonderful tool, and I use it daily to enhance my bird-walking experience, and I have often learned somewhat obscure bird calls or songs from it. But it makes many mistakes, and not only likely "close-calls" as you've described. It thinks I am an oak titmouse, almost half of the time that I am imitating a chickadee, and while "pishing" at other times, occasionally thinks I'm a barn owl. I've observed it identifying Stellar's jays as red-tailed hawks when they do their frequent imitations, and I've catched it identifying a small barking dog as a Canada goose. I would never assume that it has reliably ID'd any call or song that cannot be independently verified, and believe it should never be depended upon to do so, but it is still an extremely useful tool that I find both enjoyable and helpful in the field.
Date: 3/25/26 9:35 am From: Naomi Goodman via groups.io <nlgoodman...> Subject: Re: [pen-bird] Merlin Audio recordings - Rufous and Allen's Hummingbirds - please read.
I had the same experience at Burleigh-Murray earlier in March. I've attached a recording of a hummer that Merlin IDd as Rufous. It had a mostly rufous back with a small green patch. It doesn't surprise me that Merlin can't distinguish these two species calls. The sonograms of the "Dzeet-Chippety" calls in Peterson's Guide look very similar. If the calls are variable, it might be a tall order to improve the ID. What characteristics do you use to distinguish between the calls?
Today Chris and I birded Burleigh Murray State Park from the parking lot to a ways beyond the barn. Just a heads up…..
We saw (9) different adult male selasphorus hummingbirds which appeared to be on territory that were making vocalizations and sounds, mainly the hard ticking chip, as well as wing buzz. I used Merlin to record these sounds and made 7 recordings. And here are the results:
Merlin ID’d Rufous Hummingbird in 4 of the recordings.
Merlin ID’d Allen’s Hummingbird in 2 of the recordings.
Merlin vacillated between Rufous and Allen’s ID in 1 recording, while we watched and heard one individual bird buzz away defending it’s territory and return to it’s perch several times.
We spent time with these birds making sure we could get a view of the full backs of the birds, which were green.
I noted the 9 adult male selasphorus hummingbirds as Allen’s Hummingbirds as we know they breed at this location and by their behavior. Rufous Hummingbirds are migrants. I mention this because a very small percent of Rufous Hummingbirds can have a green back. But per Merlin, is it possible that 4 potentially 5, out of 9 adult male selasphorus hummingbirds seen today could have been green-backed Rufous Hummingbirds?
Last year an adult Allen’s male that stayed in our yard for a month or longer was consistently ID’d as both Allen’s and Rufous within multiple single recordings I made using Merlin. I was hoping Merlin would have improved. But today showed that there are still issues when it comes to ID’ing Rufous/ Allen’s Hummingbirds.
This is the time of year, folks start reporting Rufous Hummingbirds. If you are using Merlin to help with the ID, please be cautious. In the case of adult male selasphorus hummingbirds, if you do not have a lot of field experience differentiating between the sounds, vocalizations, subtle field marks, and display behaviors of these 2 species, you need to try your best to get a full-on back view to make sure the back is solid orange for Rufous Hummingbird. Not just a side view, as the amount of orange on the sides of the rump on an Allen’s can be mis-interpreted as a solid orange back. And not just a quick view of a bird zooming around quickly!
Always, when using Merlin – try to get a good visual on the bird you are recording.
I know a lot of newer birders who rely on Merlin are not on Pen-bird, please share with anyone who may benefit from this post.
Date: 3/20/26 12:57 pm From: maliadances via groups.io <maliadances...> Subject: [pen-bird] California Breeding Atlas news, info and how to join
Dear Pen-birders,
As many of you already know, California’s first statewide Breeding Bird Atlas launched on January 1, 2026. And I know many of you have already joined and are currently submitting Atlas Checklists! For those of you who have not yet joined, here is more information. This landmark effort is being led by *California Bird Atlas* ( https://www.californiabirdatlas.org/ ) (CBA), an independent nonprofit, in collaboration with state agencies, thousands of volunteers, and dozens of partner organizations.
The California Atlas Executive Director, Van Pierszalowski stated as of Mar 17th , the atlas has surpassed *50,000 Atlas checklists* across more than *4,300 blocks* from over *2,700 birders*.
And as of this morning, Mar 20 th , *San Mateo County has submitted 1692 Atlas checklists*. And a quick look at 7 Bay Area counties, we rank 2 nd for the number of Atlas Checklists already submitted to eBird.
Let me know if you have any questions about this project. And a big thanks to those who have already joined and are submitting Atlas Checklists. Happy Spring!
In Foster City, a Swamp Sparrow was in the brush along the fence on the west side of Lakeside Drive before the Mariner's Point Driving Range off of East Third Avenue. At the Ravenswood Salt Ponds on 3/7 among ( 309 ) Greater Yellowlegs were ( 24 ) Lesser Yellowlegs.
Ron Thorn
