I don't know what the trends are regarding populations of either Scaup (Scalp?) or Bufflehead but I would keep in mind that the recent heavy rain may have set off a herring spawning event (as heavy rains often do this time of year) and herring runs are known to /temporarily concentrate birds (including scaup and other bay ducks) from large areas. Also the influx of freshwater could be a catalyst for other changes in food availability thus prompting localized movement.
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some potential ideas to look into as well
On Dec 13, 2019, at 10:25, Megan Jankowski <mindfuldocumentation@...> wrote:
I feel like there are way fewer scaup on the bay then just a few years ago,
but it would be prudent to get the Oakland Christmas Bird Count data to
really show what the decline is. There is a general decline in scaup, not
just in our area:
On Fri, Dec 13, 2019 at 9:24 AM Jim Chiropolos <jnc@...> wrote:
I have worked in Emeryville for 25 years and every day I park my car by
Chevys and start the work day by looking at the bay.
For the past 24 years, in the winter, a large group of Greater Scalp
(maybe 100 to 250 plus) has always been in the bay here to greet me when I
park. This year in this location, I think the high count of scalp so far
has been 25 and usually less than 5. The scalp have been replaced by lots
and lots of Buffleheads! This week I have been counting 300 to 500
Buffleheads actively feeding from where I park in the morning. I do not
think I have ever seen this many for so long at this area. The bay bottom
here is muddy and the water is probably 2 to 4 feet deep and this is an
area that is not exposed by the tides.
I am always amazed by how little we know about common birds we see all the
time. I have questions that include:
1. Why have the greater scalp abandoned this area so far this year? (It
seems to be a year of low scalp numbers in Emeryville)
2. Why have Buffleheads moved in this year to actively feed in this area
in big numbers?
3. What do Buffleheads feed on that is different than scalp? Do
Buffleheads feed underwater using a different behavior feeding behavior or
action? Since they are smaller is the food items they feed on smaller?
4. (I have noticed over the years that Lessor Scalp prefer areas to feed
that are exposed by low tides unlike Greater Scalp that seem to prefer
5. Is what I am seeing a sign than the "Chevys" bay mud bottom ecology of
marine invertebrates or whatever the bay ducks are feeding on is different?
I know so little of bay duck behavior despite considering them a "common"
Orinda and Emeryville
PS - No sign of tufted duck after the spotting on Tuesday and the
Bar-tailed Godwit has also been missing))