Topics

Where are the Lake Merritt Scaup?


Jim Chiropolos
 

Work took me to lake Merritt today and I looked at the lake from two areas quickly and saw less than 60 scaup. Intrigued, I looked at ebird Lake Merritt sightings this month and I think the high scaup number (both lessor and greater) is 100 and for the winter 250 or so (one report - thanks Alex). The areas I looked included two of the three spots the large flock usually was. Past years, I think the lake, would hold a flock of 250 to 500 or so all winter (guess on my part)

So, I ask the question? Did I miss the big scalp flock since I did not scan the entire lake?

Or is the flock not there as the eBird reports - or do people just look for the barrows goldeneye and then are done - but has anyone birded the entire lake to establish the scaup flock size?
I worry that maybe one of the following could be occurring:
1. Lake Merritt is changing and the habitat is not holding scalp as it used to.
2. Scaup numbers overall are down - I don't bird the waterfront much these days so I do not have a sense of scaup numbers on the bay
3. Scaup are not using the lake in February

Does anyone have historical scaup flock sizes for lake merritt so we can track the flock size and where we are this year. Lake Merritt is one of the birding gems of the east bay and it would be good to know the scaup flock size as they are one of the "keystone" wintering species for the lake.

If anyone does a comprehensive scalp lake survey - can you send me your totals offline in response to this post? IT probably would be good to note it as a comprehensive lake survey in the ebird list comments - we need one of these at least every year and month if someone uses the lake as a local patch - its too far from home for me.....

I did see 8 red-breasted mergansers on the lake and I think this is a high end number for this species on the lake. I like seeing big scaup flocks on the lake in winter. This is where I learned to recognize greater scaup from lessor scalp by the nature center so it is a special place for me (and there still is a mixed group of greater and lessor scaup coming in for food.....).

Thanks,
Jim Chiropolos
Orinda

( PS on the topic of decreasing duck numbers I did not look for Barrows Goldeneyes in the channel but it has saddened me how from over 10 or more using Barrows Goldeneye were present in the winter in the channel about 10 years ago we are maybe down to one pair or so with numbers seemingly decreasing every year . The Merritt channel human habitat is very different from 10 years ago...…)


Rosemary Johnson
 

I walked the lake yesterday. I found around 100 scaup total, most in small groups of 10-20. There were more ruddy ducks. I did find 16 goldeneyes. I didn't recall seeing any mergansers. I did see canvasbacks though.

Complete list at https://ebird.org/checklist/S81803830.

On 02/16/2021 5:29 PM Jim Chiropolos <jnc@wje.com> wrote:


Work took me to lake Merritt today and I looked at the lake from two areas quickly and saw less than 60 scaup. Intrigued, I looked at ebird Lake Merritt sightings this month and I think the high scaup number (both lessor and greater) is 100 and for the winter 250 or so (one report - thanks Alex). The areas I looked included two of the three spots the large flock usually was. Past years, I think the lake, would hold a flock of 250 to 500 or so all winter (guess on my part)

So, I ask the question? Did I miss the big scalp flock since I did not scan the entire lake?

Or is the flock not there as the eBird reports - or do people just look for the barrows goldeneye and then are done - but has anyone birded the entire lake to establish the scaup flock size?
I worry that maybe one of the following could be occurring:
1. Lake Merritt is changing and the habitat is not holding scalp as it used to.
2. Scaup numbers overall are down - I don't bird the waterfront much these days so I do not have a sense of scaup numbers on the bay
3. Scaup are not using the lake in February

Does anyone have historical scaup flock sizes for lake merritt so we can track the flock size and where we are this year. Lake Merritt is one of the birding gems of the east bay and it would be good to know the scaup flock size as they are one of the "keystone" wintering species for the lake.

If anyone does a comprehensive scalp lake survey - can you send me your totals offline in response to this post? IT probably would be good to note it as a comprehensive lake survey in the ebird list comments - we need one of these at least every year and month if someone uses the lake as a local patch - its too far from home for me.....

I did see 8 red-breasted mergansers on the lake and I think this is a high end number for this species on the lake. I like seeing big scaup flocks on the lake in winter. This is where I learned to recognize greater scaup from lessor scalp by the nature center so it is a special place for me (and there still is a mixed group of greater and lessor scaup coming in for food.....).

Thanks,
Jim Chiropolos
Orinda

( PS on the topic of decreasing duck numbers I did not look for Barrows Goldeneyes in the channel but it has saddened me how from over 10 or more using Barrows Goldeneye were present in the winter in the channel about 10 years ago we are maybe down to one pair or so with numbers seemingly decreasing every year . The Merritt channel human habitat is very different from 10 years ago...…)


gabikirk@...
 

What a great question, as I have noticed the same. The huge scaup flock was on the lake earlier this winter but seems to have disappeared not long after New Years. Normally you can find decent number of scaups farther into the winter, in fact I distinctly remember seeing some as late as May last year. Weirdly though I also have not seen scaup in large numbers at some of my regular shoreline sites in recent weeks either (Arrowhead Marsh and Middle Harbor). There were hundreds at Arrowhead earlier this winter and no more. Where did they go??

Take care,

Gabi Kirk
Oakland


Steven Tucker
 

At this point in winter I suspect a large number of scaup that winter in the region are following herring runs around the bay - that could account, at least in part, for declines at sites where they were plentiful a month or two ago.


Steve Tucker
San Jose 

On Wednesday, February 17, 2021, 11:07:39 AM PST, <gabikirk@...> wrote:


What a great question, as I have noticed the same. The huge scaup flock was on the lake earlier this winter but seems to have disappeared not long after New Years. Normally you can find decent number of scaups farther into the winter, in fact I distinctly remember seeing some as late as May last year. Weirdly though I also have not seen scaup in large numbers at some of my regular shoreline sites in recent weeks either (Arrowhead Marsh and Middle Harbor). There were hundreds at Arrowhead earlier this winter and no more. Where did they go??

Take care,

Gabi Kirk
Oakland





Maureen Lahiff
 

According to Birds of the World:

Lesser Scaup spring departures can start mid February.
Their migrations are really spread out.

Greater Scaup are usually thought to start moving north in March,
but there's some question about starting to migrate north in mid February.

While day length is a big driver,
maybe there are food quality issues this year????

Maureen Lahiff


-----Original Message-----
From: gabikirk@...
To: EBB-Sightings@groups.io
Sent: Wed, Feb 17, 2021 11:07 am
Subject: Re: [EBB-Sightings] Where are the Lake Merritt Scaup?

What a great question, as I have noticed the same. The huge scaup flock was on the lake earlier this winter but seems to have disappeared not long after New Years. Normally you can find decent number of scaups farther into the winter, in fact I distinctly remember seeing some as late as May last year. Weirdly though I also have not seen scaup in large numbers at some of my regular shoreline sites in recent weeks either (Arrowhead Marsh and Middle Harbor). There were hundreds at Arrowhead earlier this winter and no more. Where did they go??

Take care,

Gabi Kirk
Oakland





Alexander Henry
 

The explanation provided by Steve Tucker is seemingly supported by eBird data; with the recent Herring Run in late January in Marin County on the northwest side of the Bay, I think some of the large concentrations of scaup which were in the East Bay earlier in the winter moved to the other side of the Bay.


Alex Henry
Berkeley


On Wed, Feb 17, 2021 at 11:38 AM Steven Tucker via groups.io <talkingtrees80=yahoo.com@groups.io> wrote:
At this point in winter I suspect a large number of scaup that winter in the region are following herring runs around the bay - that could account, at least in part, for declines at sites where they were plentiful a month or two ago.


Steve Tucker
San Jose 

On Wednesday, February 17, 2021, 11:07:39 AM PST, <gabikirk@...> wrote:


What a great question, as I have noticed the same. The huge scaup flock was on the lake earlier this winter but seems to have disappeared not long after New Years. Normally you can find decent number of scaups farther into the winter, in fact I distinctly remember seeing some as late as May last year. Weirdly though I also have not seen scaup in large numbers at some of my regular shoreline sites in recent weeks either (Arrowhead Marsh and Middle Harbor). There were hundreds at Arrowhead earlier this winter and no more. Where did they go??

Take care,

Gabi Kirk
Oakland








Bill Bousman
 

Jim and others,

I don't know if some of the numbers from the South Bay help, we do have a lot of scaup that winter there.

Please excuse me for my wonkish analyses (or just delete).  I've attached a .png figure that you should be able to see on your computer.  I have been engaged since the 1990s looking at temporal data (translation, when are bird here and when not).  What I show in this figure are the cumulative sightings for two locations in Santa Clara County.  The first data set is Alviso Slough Trail (which surrounds Pond A9 through A15 in Alviso).  That dataset is from 2007-16; the highest daily count was 6672 scaup on 29 Oct 2009.  The second data set is the rest of the South Bay in Santa Clara County, including the Alviso ponds, but there is no duplication of the Alviso ponds survey dates.  The second dataset has sightings from 1993-2016; the highest daily count was 22,500 scaup on 24 Dec 2000.  I use the word "sighting" to indicate how many birds are found in one day, that is, if I tally 3,000 scaup (here I group all Greaters, all Lessers, and all not identified to species), then that means I had 3,000 sightings.  A week later I may have recorded more or less sightings and I add them to the dataset.  So for the figure here, the total number of scaup sightings is 154,536 sightings over the time period.

The data show that most scaup have been recorded arriving in the first or second week of October and their numbers remain constant until the first week in February (the linear regression line has an r^2 value of 0.99).  There is a "break" at the beginning of February and wintering birds continue to be seen, but only at 15% of the fall and early winter rate.  My inference is that the fall birds arrive pretty much at one time in early October, most leave in early February, but some remain towards the end of March.  But these are just numbers.  I may believe my inference, but there may be far more going on than I can see from these data.

Bill Bousman
Menlo Park

On 2/16/2021 5:29 PM, Jim Chiropolos wrote:
Work took me to lake Merritt today and I looked at the lake from two areas quickly and saw less than 60 scaup. Intrigued, I looked at ebird Lake Merritt sightings this month and I think the high scaup number (both lessor and greater) is 100 and for the winter 250 or so (one report - thanks Alex). The areas I looked included two of the three spots the large flock usually was. Past years, I think the lake, would hold a flock of 250 to 500 or so all winter (guess on my part)

So, I ask the question? Did I miss the big scalp flock since I did not scan the entire lake?

Or is the flock not there as the eBird reports - or do people just look for the barrows goldeneye and then are done - but has anyone birded  the entire lake to establish the scaup flock size?
I worry that maybe one of the following could be occurring:
1. Lake Merritt is changing and the habitat is not holding scalp as it used to.
2. Scaup numbers overall are down - I don't bird the waterfront much these days so I do not have a sense of scaup numbers on the bay 
3. Scaup are not using the lake in February

Does anyone have historical scaup flock sizes for lake merritt so we can track the flock size and where we are this year. Lake Merritt is one of the birding gems of the east bay and it would be good to know the scaup flock size as they are one of the "keystone" wintering species for the lake.

If anyone does a comprehensive scalp lake survey - can you send me your totals offline in response to this post? IT probably would be  good to note it as a comprehensive lake survey in the ebird list comments - we need one of these at least every year and month if someone uses the lake as a local patch - its too far from home for me.....

I did see 8 red-breasted mergansers on the lake and I think this is a high end number for this species on the lake. I like seeing big scaup flocks on the lake in winter. This is where I learned to recognize greater scaup from lessor scalp by the  nature center so it is a special place for me (and there still is a mixed group of greater and lessor scaup coming in for food.....).

Thanks,
Jim Chiropolos
Orinda

( PS on  the topic of decreasing duck numbers I did not look for Barrows Goldeneyes in the channel but it has saddened me how from over 10 or more using Barrows Goldeneye were present in the winter in the channel about 10 years ago we are maybe down to one pair or so with numbers seemingly decreasing every year . The Merritt channel human habitat is very different from 10 years ago...…)





Joe Morlan
 

Jim,

There is a direct correlation between reduced numbers of ducks and the
discontinuing of the twice daily duck feedings at Lake Merritt a few years
ago, due in part to some people’s complaints that the birds were not
migrating (not true), and also to a lack of city funds. In addition there
have been additional claims that feeding ducks is bad for them and
unfortunately several government entities have bought into this false
narrative. E.g. duck feeding is now banned with enforcement at the famous
Palo Alto duck pond with the predictable result that most of the ducks are
no longer there.

More on the controversy from across the pond....

https://www.bbc.com/news/uk-england-derbyshire-50081386




On Tue, 16 Feb 2021 17:29:51 -0800, "Jim Chiropolos" <jnc@wje.com> wrote:

Work took me to lake Merritt today and I looked at the lake from two areas quickly and saw less than 60 scaup. Intrigued, I looked at ebird Lake Merritt sightings this month and I think the high scaup number (both lessor and greater) is 100 and for the winter 250 or so (one report - thanks Alex). The areas I looked included two of
the three spots the large flock usually was. Past years, I think the lake, would hold a flock of 250 to 500 or so all winter (guess on my part)

So, I ask the question? Did I miss the big scalp flock since I did not scan the entire lake?

Or is the flock not there as the eBird reports - or do people just look for the barrows goldeneye and then are done - but has anyone birded the entire lake to establish the scaup flock size?
I worry that maybe one of the following could be occurring:
1. Lake Merritt is changing and the habitat is not holding scalp as it used to.
2. Scaup numbers overall are down - I don't bird the waterfront much these days so I do not have a sense of scaup numbers on the bay
3. Scaup are not using the lake in February

Does anyone have historical scaup flock sizes for lake merritt so we can track the flock size and where we are this year. Lake Merritt is one of the birding gems of the east bay and it would be good to know the scaup flock size as they are one of the "keystone" wintering species for the lake.

If anyone does a comprehensive scalp lake survey - can you send me your totals offline in response to this post? IT probably would be good to note it as a comprehensive lake survey in the ebird list comments - we need one of these at least every year and month if someone uses the lake as a local patch - its too far from home for
me.....

I did see 8 red-breasted mergansers on the lake and I think this is a high end number for this species on the lake. I like seeing big scaup flocks on the lake in winter. This is where I learned to recognize greater scaup from lessor scalp by the nature center so it is a special place for me (and there still is a mixed group of
greater and lessor scaup coming in for food.....).

Thanks,
Jim Chiropolos
Orinda

( PS on the topic of decreasing duck numbers I did not look for Barrows Goldeneyes in the channel but it has saddened me how from over 10 or more using Barrows Goldeneye were present in the winter in the channel about 10 years ago we are maybe down to one pair or so with numbers seemingly decreasing every year . The Merritt
channel human habitat is very different from 10 years ago...…)
--
Joseph Morlan, Pacifica, CA