dowitcher ID


Sam Zuckerman
 

I was duly chastened some time ago by Jim Chiropolos's post admonishing us to beware of dowitcher identification in the absence of vocalization. In the linked checklist from the Emeryville Marina, I've IDed a dowitcher as Short-billed/Long-billed. But the photo is decent and I wonder if anyone would like to take a stab at species identification. https://ebird.org/checklist/S96528152




Alvaro Jaramillo
 

Sam

    Hi there, yes dowitchers are always tricky. Best thing to do is try to hear them in the field, photograph, and then study those known bird photos. Your bird yesterday looks like a Short-billed Dowitcher to me.

  1. Bill looks thicker at base and thinner in middle, Long-billed tends to look a bit more uniform in with.
  2. Very important, the bill has an obvious droop at the tip. Long-billed will look more straight billed.
  3. The bill looks relatively short. There is wide overlap as female dowitchers have longer bills than males, but the edges of the distribution are indicative of species. This looks pretty short.
  4. Can’t assess breast, but Short-billed often paler breasted in non-breeding, although this may be a feature that needs to be assessed for the West, it is based mainly on griseus subspecies in the east.
  5. That sounds like a tidal spot? One migration is done, Long-billed is typically not found in tidal/salt water areas. Similarly, in the West Short-billed winters in tidal areas and is absent from entirely fresh water spots. This is actually a very solid rule but it blurs in migration, and is reliable in winter.

 

I hope that helps. By the way, if anyone is keen on Bird ID workshops (via zoom). I have three coming up, sparrows, waterfowl and gulls. More info here:

https://www.alvarosadventures.com/events.html

 

good birding!

Alvaro

 

Alvaro Jaramillo

alvaro@...

www.alvarosadventures.com

 

From: EBB-Sightings@groups.io <EBB-Sightings@groups.io> On Behalf Of Sam Zuckerman
Sent: Sunday, October 24, 2021 7:49 AM
To: EBB-Sightings@groups.io
Subject: [EBB-Sightings] dowitcher ID

 

I was duly chastened some time ago by Jim Chiropolos's post admonishing us to beware of dowitcher identification in the absence of vocalization. In the linked checklist from the Emeryville Marina, I've IDed a dowitcher as Short-billed/Long-billed. But the photo is decent and I wonder if anyone would like to take a stab at species identification. https://ebird.org/checklist/S96528152

 

 


Stephen T Bird
 

Do you have a photo showing tail feathers, or neck and breast, face better?

It appears to be a darker gray individual without streaking/speckling in the face. Better would be to identify darker tail and get a clearer shot of clean breast, face, and neck: which would push it towards scolopaceous (LBDO).

LA birders with Dunn had a nice video, though to my recollection it might not have a lot on non-breeding. Note that some of the molting that’s occurring isn’t as informative here on SBDO breeding grounds, though timing might (it’s been awhile since I’ve reviewed it).

Stephen 

On Sun, Oct 24, 2021 at 7:48 AM Sam Zuckerman <samzuckerman@...> wrote:
I was duly chastened some time ago by Jim Chiropolos's post admonishing us to beware of dowitcher identification in the absence of vocalization. In the linked checklist from the Emeryville Marina, I've IDed a dowitcher as Short-billed/Long-billed. But the photo is decent and I wonder if anyone would like to take a stab at species identification. https://ebird.org/checklist/S96528152







Stephen T Bird
 

Hadn’t seen Alvaros. Trust him more.

On Sun, Oct 24, 2021 at 9:16 AM Stephen T Bird via groups.io <isseki.ryotoku=gmail.com@groups.io> wrote:
Do you have a photo showing tail feathers, or neck and breast, face better?

It appears to be a darker gray individual without streaking/speckling in the face. Better would be to identify darker tail and get a clearer shot of clean breast, face, and neck: which would push it towards scolopaceous (LBDO).

LA birders with Dunn had a nice video, though to my recollection it might not have a lot on non-breeding. Note that some of the molting that’s occurring isn’t as informative here on SBDO breeding grounds, though timing might (it’s been awhile since I’ve reviewed it).

Stephen 

On Sun, Oct 24, 2021 at 7:48 AM Sam Zuckerman <samzuckerman@...> wrote:
I was duly chastened some time ago by Jim Chiropolos's post admonishing us to beware of dowitcher identification in the absence of vocalization. In the linked checklist from the Emeryville Marina, I've IDed a dowitcher as Short-billed/Long-billed. But the photo is decent and I wonder if anyone would like to take a stab at species identification. https://ebird.org/checklist/S96528152










Pam Young
 

Good article on "Loral angle, supercilium, and structural placement of the eye" p34


On Oct 24, 2021, at 9:16 AM, Stephen T Bird <isseki.ryotoku@...> wrote:

Hadn’t seen Alvaros. Trust him more.

On Sun, Oct 24, 2021 at 9:16 AM Stephen T Bird via groups.io <isseki.ryotoku=gmail.com@groups.io> wrote:
Do you have a photo showing tail feathers, or neck and breast, face better?

It appears to be a darker gray individual without streaking/speckling in the face. Better would be to identify darker tail and get a clearer shot of clean breast, face, and neck: which would push it towards scolopaceous (LBDO).

LA birders with Dunn had a nice video, though to my recollection it might not have a lot on non-breeding. Note that some of the molting that’s occurring isn’t as informative here on SBDO breeding grounds, though timing might (it’s been awhile since I’ve reviewed it).

Stephen 

On Sun, Oct 24, 2021 at 7:48 AM Sam Zuckerman <samzuckerman@...> wrote:
I was duly chastened some time ago by Jim Chiropolos's post admonishing us to beware of dowitcher identification in the absence of vocalization. In the linked checklist from the Emeryville Marina, I've IDed a dowitcher as Short-billed/Long-billed. But the photo is decent and I wonder if anyone would like to take a stab at species identification. https://ebird.org/checklist/S96528152












Alvaro Jaramillo
 

Pam and others.

 

  Another article to look at, is this one on underwing patterns.

https://subalpinebirding.com/blog/strongunderwing-pattern-in-dowitchersstrong

 

I do think that we as birders, and I am guilty of this as well, accept things that are published as “truth” although in most cases no independent corroboration of these new field marks has been done. So far, the underwing feature works on birds I have photographed. However, I do not have enough in my photo collection to adequately say, yes… this is a reliable field mark.

  The loral angle, well I find it difficult to assess. Having said that, it would be a good idea for someone to take eBird photo collections of known species birds (breeding, or juveniles) and measure these on the screen. With a good enough sample size one may be able to assess again if this is reliable or not.

 

Good birding,

Alvaro

 

Alvaro Jaramillo

alvaro@...

www.alvarosadventures.com

 

From: EBB-Sightings@groups.io <EBB-Sightings@groups.io> On Behalf Of Pam Young via groups.io
Sent: Sunday, October 24, 2021 9:26 AM
To: Stephen T Bird <isseki.ryotoku@...>
Cc: EBB-Sightings@groups.io; Sam Zuckerman <samzuckerman@...>
Subject: Re: [EBB-Sightings] dowitcher ID

 

Good article on "Loral angle, supercilium, and structural placement of the eye" p34

 



On Oct 24, 2021, at 9:16 AM, Stephen T Bird <isseki.ryotoku@...> wrote:

 

Hadn’t seen Alvaros. Trust him more.

 

On Sun, Oct 24, 2021 at 9:16 AM Stephen T Bird via groups.io <isseki.ryotoku=gmail.com@groups.io> wrote:

Do you have a photo showing tail feathers, or neck and breast, face better?

 

It appears to be a darker gray individual without streaking/speckling in the face. Better would be to identify darker tail and get a clearer shot of clean breast, face, and neck: which would push it towards scolopaceous (LBDO).

 

LA birders with Dunn had a nice video, though to my recollection it might not have a lot on non-breeding. Note that some of the molting that’s occurring isn’t as informative here on SBDO breeding grounds, though timing might (it’s been awhile since I’ve reviewed it).

 

Stephen 

 

On Sun, Oct 24, 2021 at 7:48 AM Sam Zuckerman <samzuckerman@...> wrote:

I was duly chastened some time ago by Jim Chiropolos's post admonishing us to beware of dowitcher identification in the absence of vocalization. In the linked checklist from the Emeryville Marina, I've IDed a dowitcher as Short-billed/Long-billed. But the photo is decent and I wonder if anyone would like to take a stab at species identification. https://ebird.org/checklist/S96528152

 

 







 


Sam Zuckerman
 

Thanks to Pam, Stephen and especially Alvaro for responses to the dowitcher query. The bird in the photo was roosting with godwits, Western Sandpipers, Dunlin, turnstones, and thousands of other shorebirds on the southern rip-rap seawall on Emeryville Peninsula across Powell Street from the marina. I don't have other photos of this bird. I'm persuaded by Alvaro's discussion of SBDO vs. LBDO bills that this bird is Short-billed, although for now I'm leaving the ID Short-billed/Long-billed on the eBird checklist. Clearly, habitat is an important clue, but we know that the salt water/fresh water distinction doesn't always hold. Alas, the bird was roosting and didn't make any sound. In any case, it would have been drowned out by the Willets!
On 10/24/2021 9:40 AM Alvaro Jaramillo <chucao@...> wrote:


Pam and others.


  Another article to look at, is this one on underwing patterns.

https://subalpinebirding.com/blog/strongunderwing-pattern-in-dowitchersstrong


I do think that we as birders, and I am guilty of this as well, accept things that are published as “truth” although in most cases no independent corroboration of these new field marks has been done. So far, the underwing feature works on birds I have photographed. However, I do not have enough in my photo collection to adequately say, yes… this is a reliable field mark.

  The loral angle, well I find it difficult to assess. Having said that, it would be a good idea for someone to take eBird photo collections of known species birds (breeding, or juveniles) and measure these on the screen. With a good enough sample size one may be able to assess again if this is reliable or not.


Good birding,

Alvaro


Alvaro Jaramillo

alvaro@...

www.alvarosadventures.com


From: EBB-Sightings@groups.io <EBB-Sightings@groups.io> On Behalf Of Pam Young via groups.io
Sent: Sunday, October 24, 2021 9:26 AM
To: Stephen T Bird <isseki.ryotoku@...>
Cc: EBB-Sightings@groups.io; Sam Zuckerman <samzuckerman@...>
Subject: Re: [EBB-Sightings] dowitcher ID


Good article on "Loral angle, supercilium, and structural placement of the eye" p34




On Oct 24, 2021, at 9:16 AM, Stephen T Bird <isseki.ryotoku@...> wrote:


Hadn’t seen Alvaros. Trust him more.

 

On Sun, Oct 24, 2021 at 9:16 AM Stephen T Bird via groups.io <isseki.ryotoku=gmail.com@groups.io> wrote:

Do you have a photo showing tail feathers, or neck and breast, face better?

 

It appears to be a darker gray individual without streaking/speckling in the face. Better would be to identify darker tail and get a clearer shot of clean breast, face, and neck: which would push it towards scolopaceous (LBDO).

 

LA birders with Dunn had a nice video, though to my recollection it might not have a lot on non-breeding. Note that some of the molting that’s occurring isn’t as informative here on SBDO breeding grounds, though timing might (it’s been awhile since I’ve reviewed it).

 

Stephen 

 

On Sun, Oct 24, 2021 at 7:48 AM Sam Zuckerman <samzuckerman@...> wrote:

I was duly chastened some time ago by Jim Chiropolos's post admonishing us to beware of dowitcher identification in the absence of vocalization. In the linked checklist from the Emeryville Marina, I've IDed a dowitcher as Short-billed/Long-billed. But the photo is decent and I wonder if anyone would like to take a stab at species identification. https://ebird.org/checklist/S96528152

 

 









Sam Zuckerman
samzuckerman@...
510-375-3861


rfs_berkeley
 

What I had understood, from conversations years ago with PRBO (now Pt Blue) biologists is that substrate and not salinity is the issue.  That Short-billed strongly prefer an admixture of sand and a firm substrate; that Long-billed did well in muddy softer substrate.  He thought that Long-billed was the more abundant bird in many of the tidal marshes and actually the more abundant species, at least in the North Bay, in Winter.

Now this information is perhaps 15 years old. 

Has substrate been discussed among shorebird biologists?

   -Rusty Scalf

    Berkeley


  1. That sounds like a tidal spot? One migration is done, Long-billed is typically not found in tidal/salt water areas. Similarly, in the West Short-billed winters in tidal areas and is absent from entirely fresh water spots. This is actually a very solid rule but it blurs in migration, and is reliable in winter.

 

 


Peter Pyle
 

Hi Rusty and all -

The findings on substrate are correct but this and salinity are confounded so it is difficult to then say that there is not a salinity effect as well. However it goes, in winter, Short-billed Dowitchers are quite confined to estuarine habitats here in the Bay Area, whereas Long-billeds are more broadly distributed, including in fresher water habitats. The two can occur together where creeks empty into estuaries, though I still see the two species segregate in these situations to some extent.

Personally I'd not feel that comfortable identifying this dowitcher based on the one image. Nothing ever wrong with silent "SB/LBDO"s in winter. I also have a hard time with the loral angle character - if it is there, it seems quite dependent on the bird's disposition and posture. For me the best thing in winter is bill length, with >60% non-overlap, so among a flock of birds there will be some that are out of range from the other species, and with experience you can get these and then make assumptions about the rest of the flock.

Enjoy the rain, we've got a good one going,

Peter

At 10:46 AM 10/24/2021, rfs_berkeley wrote:

What I had understood, from conversations years ago with PRBO (now Pt Blue) biologists is that substrate and not salinity is the issue. That Short-billed strongly prefer an admixture of sand and a firm substrate; that Long-billed did well in muddy softer substrate. He thought that Long-billed was the more abundant bird in many of the tidal marshes and actually the more abundant species, at least in the North Bay, in Winter.

Now this information is perhaps 15 years old.

Has substrate been discussed among shorebird biologists?

-Rusty Scalf

Berkeley

* That sounds like a tidal spot? One migration is done, Long-billed is typically not found in tidal/salt water areas. Similarly, in the West Short-billed winters in tidal areas and is absent from entirely fresh water spots. This is actually a very solid rule but it blurs in migration, and is reliable in winter.




SteveLombardi
 

Long-billed eBird postings for Nov-Decindicate that Long-billed are quite common around the bay, presuming that most of these postings are accurate.
https://ebird.org/map/lobdow?neg=true&env.minX=&env.minY=&env.maxX=&env.maxY=&zh=false&gp=false&ev=Z&mr=on&bmo=11&emo=12&yr=all&byr=1900&eyr=2021

Surprises me. I assumed that most this habitat was too briny for Long-billed. Are they finding little brackish or fresh water spots to exploit?


Edward Vine
 

I had similar information in the 1970s that you had - also from PRBO: generally, LBDOs along the coast and SMDOs inland. Similar guidance for Yellowlegs: Greater along the coast and Lesser inland.

Not sure if things have changed since then.

Ed

On Sun, Oct 24, 2021 at 12:13 PM Peter Pyle <ppyle@...> wrote:
Hi Rusty and all -

The findings on substrate are correct but this and salinity are
confounded so it is difficult to then say that there is not a
salinity effect as well. However it goes, in winter, Short-billed
Dowitchers are quite confined to estuarine habitats here in the Bay
Area, whereas Long-billeds are more broadly distributed, including in
fresher water habitats. The two can occur together where creeks empty
into estuaries, though I still see the two species segregate in these
situations to some extent.

Personally I'd not feel that comfortable identifying this dowitcher
based on the one image. Nothing ever wrong with silent "SB/LBDO"s in
winter. I also have a hard time with the loral angle character - if
it is there, it seems quite dependent on the bird's disposition and
posture. For me the best thing in winter is bill length, with >60%
non-overlap, so among a flock of birds there will be some that are
out of range from the other species, and with experience you can get
these and then make assumptions about the rest of the flock.

Enjoy the rain, we've got a good one going,

Peter

At 10:46 AM 10/24/2021, rfs_berkeley wrote:

>What I had understood, from conversations years ago with PRBO (now
>Pt Blue) biologists is that substrate and not salinity is the
>issue.  That Short-billed strongly prefer an admixture of sand and a
>firm substrate; that Long-billed did well in muddy softer
>substrate.  He thought that Long-billed was the more abundant bird
>in many of the tidal marshes and actually the more abundant species,
>at least in the North Bay, in Winter.
>
>Now this information is perhaps 15 years old.
>
>Has substrate been discussed among shorebird biologists?
>
>    -Rusty Scalf
>
>     Berkeley
>
>>    * That sounds like a tidal spot? One migration is done,
>> Long-billed is typically not found in tidal/salt water areas.
>> Similarly, in the West Short-billed winters in tidal areas and is
>> absent from entirely fresh water spots. This is actually a very
>> solid rule but it blurs in migration, and is reliable in winter.
>>
>>
>>
>>
>
>






--
Edward Vine

Lawrence Berkeley National Laboratory
Building 90R2002
Berkeley, CA 94720-8136

Phone:     1-510-486-6047
Email:    elvine@...


Edward Vine
 

Oops. Should have been SBDOs, not SMDOs.

Ed

On Mon, Oct 25, 2021 at 4:47 PM Edward Vine via groups.io <elvine=lbl.gov@groups.io> wrote:
I had similar information in the 1970s that you had - also from PRBO: generally, LBDOs along the coast and SMDOs inland. Similar guidance for Yellowlegs: Greater along the coast and Lesser inland.

Not sure if things have changed since then.

Ed

On Sun, Oct 24, 2021 at 12:13 PM Peter Pyle <ppyle@...> wrote:
Hi Rusty and all -

The findings on substrate are correct but this and salinity are
confounded so it is difficult to then say that there is not a
salinity effect as well. However it goes, in winter, Short-billed
Dowitchers are quite confined to estuarine habitats here in the Bay
Area, whereas Long-billeds are more broadly distributed, including in
fresher water habitats. The two can occur together where creeks empty
into estuaries, though I still see the two species segregate in these
situations to some extent.

Personally I'd not feel that comfortable identifying this dowitcher
based on the one image. Nothing ever wrong with silent "SB/LBDO"s in
winter. I also have a hard time with the loral angle character - if
it is there, it seems quite dependent on the bird's disposition and
posture. For me the best thing in winter is bill length, with >60%
non-overlap, so among a flock of birds there will be some that are
out of range from the other species, and with experience you can get
these and then make assumptions about the rest of the flock.

Enjoy the rain, we've got a good one going,

Peter

At 10:46 AM 10/24/2021, rfs_berkeley wrote:

>What I had understood, from conversations years ago with PRBO (now
>Pt Blue) biologists is that substrate and not salinity is the
>issue.  That Short-billed strongly prefer an admixture of sand and a
>firm substrate; that Long-billed did well in muddy softer
>substrate.  He thought that Long-billed was the more abundant bird
>in many of the tidal marshes and actually the more abundant species,
>at least in the North Bay, in Winter.
>
>Now this information is perhaps 15 years old.
>
>Has substrate been discussed among shorebird biologists?
>
>    -Rusty Scalf
>
>     Berkeley
>
>>    * That sounds like a tidal spot? One migration is done,
>> Long-billed is typically not found in tidal/salt water areas.
>> Similarly, in the West Short-billed winters in tidal areas and is
>> absent from entirely fresh water spots. This is actually a very
>> solid rule but it blurs in migration, and is reliable in winter.
>>
>>
>>
>>
>
>






--
Edward Vine

Lawrence Berkeley National Laboratory
Building 90R2002
Berkeley, CA 94720-8136

Phone:     1-510-486-6047
Email:    elvine@...





--
Edward Vine

Lawrence Berkeley National Laboratory
Building 90R2002
Berkeley, CA 94720-8136

Phone:     1-510-486-6047
Email:    elvine@...


Joe Morlan
 

On Mon, 25 Oct 2021 16:47:00 -0700, "Edward Vine" <elvine@lbl.gov> wrote:

I had similar information in the 1970s that you had - also from PRBO: generally, LBDOs along the coast and SMDOs inland. Similar guidance for Yellowlegs: Greater along the coast and Lesser inland.
This is definitely wrong. Short-billed Dowitchers are decidedly rare
inland in California at any season. They are fairly common in estuaries
with tidal mudflat in migration. In winter they occur only in the largest
estuaries such as San Francisco Bay, San Diego Bay, etc.

Long-billed Dowitchers outnumber Short-billed in the winter with most
occurring in fresh water habitat inland, but also in coastal estuaries
where they may occur with Long-billed. There Long-billed tend to
concentrate at creek mouths with emergent vegetation where they keep up a
constant series of contact notes. They tend to segregate from Short-billed
which prefer open mudflat without vegetation where they usually forage
silently, calling only when spooked or in flight.

Both Greater and Lesser Yellowlegs prefer fresh water habitats with
emergent vegetation. Greaters vastly outnumbering Lessers throughout
California in migration and especially in winter when Lessers become
extremely rare.
--
Joseph Morlan, Pacifica, CA