Date: 3/23/21 11:56 am
From: Range Bayer <range.bayer...>
Subject: [obol] Significant Increase in Harlequin Ducks at Yaquina Bay since 1992
Hi,

In my earlier post today ("Large Numbers of Harlequin Ducks West Of Yaquina
Bay Bridge. Many Gulls at Herring Spawn Site"), I forgot to look up my
earlier paper (Bayer, R. D. 1994. Harlequin Duck records mostly from
Lincoln County,Oregon. Journal of Oregon Ornithology 3:243-260) that is
freely available to download through ScholarsArchive@OSU (
https://ir.library.oregonstate.edu/concern/articles/dj52w9646).

This was based on all Lincoln Co. records compiled through 1992. From the
Abstract: "612 Harlequin Duck records are given for Lincoln County, and
another 74 records are listed for other coastal counties. In Lincoln
County, Harlequins are found mostly in winter, there were often more males
than females, *the most ever counted was 14 *[which was at Yaquina Bay, see
p. 247], and there is no indication that they nested. In contrast, Alex
Walker's unpublished nesting record in 1940 is given for Tillamook County,
and as many as 75 Harlequins were found in June along the Lane County
coast, so they may nest nearby, as Gordon (1984) reports."

Now, Harlequin maximum counts are regularly in the 30's as indicated in
eBird (see my earlier post).

That is a big jump from a maximum of 14 over many years to 41 and in the
30s in recent years. I haven't compiled Lincoln Co. records since 1992 to
determine when the increase may have occurred. But a tedious, time
consuming search for "Harlequin" in the Search Box at
http://yaquina.info/ybn/bird/bird.htm may show when. That search box is
for records given in the bird field notes given in the newsletter of
Yaquina Birds and Naturalists.for 1993-2015 (
http://yaquina.info/ybn/bird/bird.htm#1993-2015). Alas, I can't do this
now.

Happy birding,

Range Bayer, Newport, Oregon.

 
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