Date: 12/30/18 6:10 pm
From: Aidan Kiley via CTBirds <ctbirds...>
Subject: [CT Birds] Fairfield/Bridgeport Scaup reminder
Hi all,

As we are getting further into winter duck season, I wanted to mention a
few things about scaup ID, specifically on the Fairfield/Bridgeport flock.

Captain's Cove in Bridgeport is a known traditional wintering spot for
numbers of Lesser Scaup. The ratio varies year to year and month by month
each year, but typically, the majority of scaup at this location are
Lesser. Greaters are also present, but in smaller numbers.

eBird makes it easy to report and track numbers of each scaup species, but
also gives way to making assumptions about the ratios, a problem, since
eBird is in itself a scientific database that obviously strives for
accuracy in data. Watching eBird checklists over time, I see a number of
reports that do not seem to align with the current generally known
distribution of scaup at those times, such as Captain's Cove reports with
only Greater or mostly Greater with no detail as to how that conclusion was
reached.

Recently at Jennings' Beach, part of the Captain's aythya flock
(containing the Tufted) has been present offshore. Having searched through
them on multiple different days, I noted that the vast majority of them are
Lessers. eBird checklists of this current flock that report mainly (or
only) Greater cause conflict in the data, resulting in inaccuracies one way
or the other. Please use caution in what numbers of these species you are
reporting from Jennings' or Captain's-- make a careful estimate, and if
not, enter them as Greater/Lesser Scaup. It's not at all useful to simply
enter Greater or Lesser without going through the flock.

Another caution about Jennings' is that we tend to think of flocks of
scaup on the Sound itself as mostly Greaters. This is usually true, but
this current aythya flock off of Jennings' is an exception.

Scaup identification makes this more challenging. Greg Hanisek has sent
detailed posts in the past about their identification.

Also on a (somewhat) unrelated note, there is a female scaup off of
Jennings' that nearly completely lacks any white on the face. Its face
looks completely brown from a distance. Using additional features is
important in identifying the Tufted.

Aidan Kiley
Fairfield
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