Date: 3/14/17 9:17 am
From: Jeff Gilligan <jeffgilligan10...>
Subject: [obol] Re: Scaup species along Columbia River
The great increase in Greater Scaup, and diving ducks in general along the Columbia River (particularly near Portland) is a relatively recent. I am not sure when it started, perhaps about 20 years ago. (Gabrielson and Jewett mentioned the diving ducks on the river int here book so I was surprised that I was unable to find many.). The stretch of the river from just east of the Portland airport to and including Hayden Island was part of my section of the Portland Christmas Bird Count for many years. I always scanned the river. I would see grebes and the occasional loon and a few Double-crested Cormorants, but very few ducks. Often the little cove near the manufactured home park on Hayden Island was the only place where there would be any diving ducks. Harry Nehls and I have discussed this. Harry said that he had heard that a fresh water mussel (or was it a clam) had colonized the river. Perhaps Harry or someone else can chime in and correct me or add more information.

Jeff Gilligan

> On Mar 13, 2017, at 3:09 PM, Russ Namitz <namitzr...> wrote:
> I have always assumed that large rafts of Scaup sp. along rivers in Oregon were almost entirely LESSER SCAUP (e.g. Scaup flock off Marine Drive at PDX airport, Dean Creek Wildlife Area east of Reedsport) and I have confirmed that first-hand while stopping to scan through these flocks. As I was driving along the Columbia River around the Biggs area in Sherman County yesterday, I assumed the large raft was also predominately Lesser Scaup, but in fact, when I scoped the flock, I estimated 80% of the 1000 birds were GREATER SCAUP. Perhaps this is not news to old time Oregon birders, but I was surprised.
> Good birding,
> Russ Namitz

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