East Bay Birding - Sightings

Re: Nuttall's White-Crowned Sparrows - singing at Inspiration Point

When Dominik Mosur was on the GGBA board (this would have been spring 2019, when we were still in the old office on San Pablo), I remember him coming to a board meeting very excited--walking down San Pablo avenue he had spotted an active White-crowned Sparrow nest by the Bank of America. I remember him remarking at the time how rare he thought this was (of course I thought it was amazing that any bird could breed living within such close proximity to that stretch of San Pablo....)

Eric Schroeder

Re: Nuttall's White-Crowned Sparrows - singing at Inspiration Point

Thank you Ethan for the very informative  commentary - and apologies for misrepresenting you on the past record of breeding Nuttalli at Inspiration Point. 


Re: Nuttall's White-Crowned Sparrows - singing at Inspiration Point

Hi Zac,

Thanks for posting, and I would encourage anyone that discovers strange or out of place summering White-crowned Sparrows to share, as well! 

I would like to mention that I am not actually aware when White-crowned Sparrows last bred here. Zac, you might have been misinterpreting what I said regarding my personal experiences here? 

I should also correct something I said a while ago, where I mentioned that I was not aware of any contractions in the breeding range of Nuttall's White-crowned Sparrows in the East Bay, only expansions. Either at that time I had forgotten about the Tilden birds or was not aware that they once existed, as it is true, White-crowned Sparrows were once abundant around South Park Dr., Anza View Meadow, Inspiration Pt. and there are several papers written on these birds. But in recent years the species has been mostly (completely?) absent here. 

It is interesting, the literature indicates that nuttall's White-crowned Sparrows are extremely sedentary and almost never move or disperse, but I think part of the full picture is missing. Clearly, nuttalli White-crowned Sparrows can appear at a well-birded location where they have been absent for years like Inspiration Pt., but we also have a record of summering nuttalli White-crowned Sparrow in Walnut Creek, like 5+ miles from the closest breeders, in 1986 and 1987. And of course there is this record, of an adult. male banded in Marina Bay, Richmond 2016-06-08 and refound at the Golden Gate Bridge Toll Plaza 2020-04-20 (Jonah Benningfield, https://ebird.org/checklist/S68169827). 

This winter an adult nuttalli White-crowned Sparrow appeared in the Richmond Marina that sounds quite different from the local birds, and it is still there as of last week. I don't know where it came from, but it seems a safe guess based on the song that it, too, came from somewhere else! 

Ethan Monk

Nuttall's White-Crowned Sparrows - singing at Inspiration Point

While perhaps far less exotic than my report on the hybrid bunting, a highlight of my recent visits to the Inspiration Point area was finding a singing White-crowned Sparrow of our resident Nuttalli subspecies (with a possible second bird seen with it yesterday).  Based on info from Ethan Monk, the last reported breeding record for this spot was about 10 years ago!

I'm not a researcher and my knowledge on White-crowneds is quite basic, but as a local birder, I'm aware that 3 subspecies regularly occur here. Two breed further North (pugetensis and gambelii) and overwinter in our area, while the nutalli subspecies are year-round residents of mostly coastal areas. 

I remember learning in college how nuttalli White-crowned Sparrows were the subject of groundbreaking research in the 60s through the 80s, because they have numerous song dialects (with something like 6 distinct dialects in Point Reyes alone). But Ethan pointed out today that there was once a White-crowned song dialect termed the 'Tilden Dialect', with Inspiration Point being a key study site, which I didn't know about! I thought that was super interesting. 

Skimming through some research abstracts today, I even saw this referred to in one paper as the 'Inspiration Point dialect'. It's a bit disheartening therefore to think about these birds (with their dialect) having disappeared as breeders in this spot. A lone bird singing there for the first time in years isn't much, but it's at least a little hopeful.

Decades ago, I did a few field internships at the Palomarin Field Station (run by Point Blue Conservation Science) where I banded some of these nuttalli birds. At Palomarin, we would occasionally stumble into old live traps that one groundbreaking researcher, Luis Baptista, used to catch White-crowneds. He would raise them, exposing them to different songs and compare them to wild birds to tease out how White-crowneds acquire their songs and other details. Baptista was also apparently the person who termed the 'Tilden dialect' of White-crowned Sparrows. 

So maybe keep your eyes and ears out for singing White-crowneds in Tilden and other areas of the East Bay hills. While a common bird that we tend to ignore, it's worth keeping track of where they breed locally. 

I just thought I'd share this. Pardon in advance any inaccuracies (corrections welcome), but I thought this was of at least local interest. 

Zac Denning

Lazuli x Indigo Bunting Hybrid near Inspiration Point

On Saturday late afternoon, my wife Adrienne and I found a male Lazuli x Indigo Bunting hybrid, on EBMUD land about 3/4 mile from the Inspiration Point parking lot. (Please pardon the delay: I was asked to wait for additional expert feedback before reporting this bird)

The bird has a deeper royal/indigo blue tint than the pale turquoise of a pure Lazuli (especially on the face), with blue extending a bit further down the breast, with white underparts and only faint hints of orange on the upper breast. The wings include a patchy white upper wing bar, no lower wingbar, with more blue (and no white edging) on the tertials and pretty extensive blue on the coverts and secondaries. He was singing away, sounding quite Lazuli, though it was pointed out that Indigo sounds very similar, and oscines in any case learn their songs. Among the expert feedback on the bird (4 out of 5 calling this a hybrid), one person suggested this may be a backcross with Lazuli. In any case, it's certainly cool looking! See photos further below, along with a highlighted map screenshot of the area. 

Yesterday, I revisited the bird, accompanied by Jack Hayden and Lyla Arum. We also ran into Erica Kawata, who later observed the bird as well. 

The bird often sings from a small Elderberry tree at about 37.911099, -122.248667, or from the neighboring Hemlock or Coyote Brush, as well as a large dead live oak at 37.910766, -122.248322 and nearby Bay Laurels. This is very close to where the Inspiration Trail (EBMUD) intersects with the paved Nimitz Way trail (at the edge of Tilden). During the middle of the day, the bird sings less often or from deep foliage, so some patience may be required. 

Notes on getting there: 
I'd recommend walking along Nimitz Way until you reach the locked metal gate at 37.911151, -122.249665, then climbing over the gate, which takes you to the edge of what seems to be the bird's territory. The gate has a "No Trespassing" sign facing Nimitz, but as far as I'm aware anyone with an EBMUD permit is permitted to be on the other side. EBMUD trail permits are low cost, and give access to lots of trails with good birding. 

EBMUD permit holders can also take the more direct Inspiration Trail (EBMUD) from the Inspiration Point parking lot, but please note there are a lot of ticks in the tall grass along this path right now. We found at least 6 - hence my recommendation to walk on Nimitz. The ticks are also in the hybrid bunting area, so be sure to check carefully.

Thanks to Ethan Monk and others for their input.

Happy birding,

Zac Denning



Map with highlighting showing areas where the bird has been observed: 

Re: Wilson's Warblers behavior at Tilden

FWIW, I thought I saw a loon off Muir Beach in Marin County on 5/17. It wasn't close enough to see plumage well, but it certainly had the shape of a loon. I was surprised to see one hanging around this late.

Alan Howe
North Oakland

Re: Wilson's Warblers behavior at Tilden

Thanks Raleigh, good to know, always good to see NOHAs and now there is a reason to look more closely.  Now we just need some research on the effect of the different plumages on breeding success.

On 5/26/2024 7:38 AM, Raleigh McLemore via groups.io wrote:

Memorial weekend birds and memories

Rosita and I drove to Muir Picnic area short of the Mount Diablo summit yesterday.  It is a sort of annual thing to visit my birding mentors, Florence Bennett, Betty Gallagher, Mary Jane Culver and Jean Richmond.  They took me under their wings in the early 90s and once showed me the garden of Red Columbines under the trees there.  I sat on my stool remembering and thanking.  As we sat under the trees at Muir Picnic, the spirit on our friends appeared in the form of a female Anna's Hummingbird which came to feed on the Columbines.  Then Rosita pointed out behind the Columbines some tall White Larkspurs, which I had only known from MP 5.75 on Mines Road.  As we walked around the area we found a Hermit Warbler, Scrub Jays and Titmice.

Thanks to rain and possible lightning in Indianapolis and a delay of the car racing, I decided to go to Martinez this morning for birds.  It was wonderful.  I finally found a single Red-necked Phalarope in the Waterbird Way Pond, along with Tree, Barn and Cliff Swallows.  The Stilts and Avocets were noisy. Mallards with ducklings and Gadwall, too. Across the pond I was able to find a continuing pair of Cinnamon Teals.  Using binoculars only this was good for me.  I am unable to lift a scope right now, having received my third defibrillator Wednesday morning.

I birded McNabney Marsh from the taco truck corner.  A Brown Pelican headed off toward the northwest corner and out of view.  I found three very small Avocets with mom and dad.  I think the babies were swimming based on how deep the water seemed to be for the parents.  I started counting and found fifty or so Mute Swans.  Down a channel to the west were at least two swanlets.  I know cygnets is the correct word, but these seemed to be too small for that term.  When I finished counting I looked back and finally re-found the Avocet chicks on a mudflat, looking happy to have solid ground under them.

I next drove east on Waterfront Road.  Short of the bridge over Walnut Creek and the end of public access, I found another Cinnamon Teal pair in the mud puddles along the edge of the road.  Marsh Wrens were singing.  I then stopped to take a short walk out the TransMontaigne Pipeline trail.  I went as far as Eric's memorial; if you have ever been, you will know what I mean.  A singing Mockingbird may have been helping to protect a Killdeer nest with four eggs.  More Stilts and Avocets in the largest pond out there along with Snowy and Great Egrets.  As I walked back a male Blue-winged Teal flew from a very small wet area west of the trail.  It flew to the larger pond to the east and seemed to join a female.

On the way home I stopped to visit with Chris and Teri Wills.  While sharing stories outside their garage, a male Hooded Oriole came to one of their feeders, Red-tailed Hawks soared, a CA Quail came to the yard and a female Cowbird perched above the feeders.

Wonderful birds and memories.  Happy Memorial Day.

Hugh B. Harvey
Walnut Creek

Re: Wilson's Warblers behavior at Tilden

Reply to the question of adult bird plumage being variable.  In Harriers at least it appears that the "Grey Ghost" of the adult harrier is less a sure thing than I thought.  Not speaking to the reason for variability it seems that observations show adult male harriers may have considerable color variation.  The beautiful "grey ghost" is a bit rarer among adult harriers than we thought:


Not a bird brain or expert but food for thought in any case.

Re: Wilson's Warblers behavior at Tilden

Well, this is San Francisco, any gender is free to dress as they like!

This seems to be the place to mention a nature show I saw years ago--don't remember exactly, but it was reputable, on KQED i think--that said that in England some male harriers retained their juvenile plumage, so they were ignored by the breeding males, and could stick around and sneak in to mate.  The show claimed about half of the males shared this feature, so evidently a successful strategy.  This was remarkable enough that I thought it would have diffused in the birding world, and others would have run across it as well, but nothing.  A brief foray into Harrier ID (Hen Harriers) mentions nothing about this, so I have to doubt the show, and lose one of my favorite stories.  Anyone else have any contact with this idea?

William Hudson

Fremont birding

Hello birders,
I was off in Cozumel when Sharon Jue first reported the Bell's Vireo at Pacific Linear Park so it wasn't until today that I was able to make the pilgrimage to pay homage. Just as advertised, the Vireo was busy ringing the Bell when I arrived. I got a couple satisfactory photos and perhaps a decent recording. Also of possible interest (at least to me): an immature White-tailed Kite was already off the nest and kiting for prey over the fields, showing its buffy chest. I have no idea where the adults might have been. Four swallow species were hawking over the far pond. A Common Gallinule was tending to a single chick.

I then moseyed over to Lake Elizabeth and walked the perimeter of the marsh area, including the southeast shore of the lake, the bike path south along the railroad tracks, and then Stivers natural area. Best bird was a singing Yellow-breasted Chat. I eventually got a couple ok photos and a passable sound recording before it flew over to the island. I also heard a Western Tanager at one point. Otherwise, it was the usual suspects.

Ebird list for Pacific Commons here: https://ebird.org/checklist/S177025015
Lake Elizabeth checklist here: https://ebird.org/checklist/S177065084

Bird on,

Bruce Mast

Re: Wilson's Warblers behavior at Tilden

Wow, that’s interesting. I had no idea. I wonder how many ‘males’ I’ve identified in my previous eBird reports that are actually female...

Common Loon at Lake Merritt, Oakland on 5/24/24

Greetings Birders,

Yesterday, Friday afternoon, I spotted what turned out to be a Common Loon fishing and preening in the middle of Lake Merritt. Many thanks to Zac Denning for helping to ID the type of loon and to Lee Aurich who came out to photograph it (enjoy links to his photos below). 




Happy Birding!


Re: Wilson's Warblers behavior at Tilden

The second "male" was almost certainly a female in a male-like plumage. In
fact the vast majority of adult females of the West Coast population have a
male-like plumage aspect. I first became aware of this when I witnessed

Eastern populations are more dimorphic with many if not most females have a
recognizably different plumage although most still have an outline or trace
of a dark cap.

On Fri, 24 May 2024 20:21:10 -0700, "Melani King via groups.io"
<melani@...> wrote:

I spent several hours today at Tilden Park near Jewel Lake. It was breezy and more quiet than the past two visits there but I observed something that I'm wondering if anyone else has seen or has an explanation. I was alerted by the usual chip vocalization and saw two males carrying food. They were moving almost continuously and
one was fluttering its feathers frequently like fledglings do when begging. I didn’t see a female but I think there was a nest in the lower vegetation that I observed one of these birds go into. Birds of the World mentions polygyny in some montane populations but this is two males. Is there any possibility that they were competing
for the female? Or?

I got several photos of them with beaks full of food and a poor quality one of both of them on a branch.
Joseph Morlan, Pacifica, CA

Wilson's Warblers behavior at Tilden

I spent several hours today at Tilden Park near Jewel Lake. It was breezy and more quiet than the past two visits there but I observed something that I'm wondering if anyone else has seen or has an explanation. I was alerted by the usual chip vocalization and saw two males carrying food. They were moving almost continuously and one was fluttering its feathers frequently like fledglings do when begging. I didn’t see a female but I think there was a nest in the lower vegetation that I observed one of these birds go into. Birds of the World mentions polygyny in some montane populations but this is two males. Is there any possibility that they were competing for the female? Or?

I got several photos of them with beaks full of food and a poor quality one of both of them on a branch.

Re: apparent Costas x Anna's hummingbird hybrid in Alameda County


Thank you for getting another opinion and sharing the thoughts on that odd hummingbird. 

When these two species intermix, could either species be male or female, or is there a more expected/common direction that they hybridize? (Awkwardly phrased, but hopefully you get my intent.) 

Erica Rutherford

Downy Woodpecker feeding her young

I was north of the Tilden Little Farm this afternoon and a couple of birders pointed out a nest in a nearby tree.  I have walked past this location several times and not noticed.  Both the male and female Downy Woodpeckers were flying back and forth feeding grubs to more than one youngsters who have not yet fledge.  The young birds were able to stick their heads out the nest hole, one at a time.  Amazing sight.

Photo of the female feeding one of here young on Flickr. 
Claude Lyneis
Flickr Photos at https://flic.kr/ps/36it5P

Rose-breasted Grosbeak in backyard near Fruitvale

Hello EBBirders,

A very kind community member, Gail, reached out to GGBA to share she had a Rose-breasted Grosbeak in her backyard bird feeder near Fruitvale in Oakland. She's not on eBird nor the listservs but generously offered to let us spread the word. 

If you are interested in requesting access you can email her at gail1grassi@....

Note, the bird was singing but Merlin was calling it a Robin so trust your ears out there.    

Happy birding!


Re: Hooded Oriole mimicry

I took a quick look at the Peterson guide to bird sounds of western North America, by Nathan Pieplow, and it said:
"Hooded Orioles have a reputation for singing less than other orioles, but song is perhaps overlooked because it is rather soft and jumbled. Imitations of other species often make up the majority of song." 
I did not look at the Birds of the World account at the Cornell site.
John Harris
Oakdale, CA. 

Hooded Oriole mimicry

I heard a Hooded Oriole mimic an American Robin several times in my neighborhood in Alameda this morning. I’ve never heard this before so I did a quick google search of Hooded Oriole mimicry and the only examples I could find was them mimicking Gila Woodpeckers and Ash-throated Flycatchers in Arizona.

Good birding!

Chris Waterman

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