Date: 3/23/21 11:56 am From: Range Bayer <range.bayer...> Subject: [obol] Significant Increase in Harlequin Ducks at Yaquina Bay since 1992
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 In contrast, Alex Walker's unpublished nesting record in 1940 is given for Tillamook County, and as many as 75 Harlequins were found in June along the Lane County coast, so they may nest nearby, as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.