Date: 3/7/17 10:46 pm From: Joel Geier <joel.geier...> Subject: [obol] Re: Trumpeter swans in the Willamette basin
Sorry, catching up on this discussion in digest mode....
Trumpeter Swan numbers in southern Polk County have been declining for several years now. A decade ago we used to see about 40 birds pretty regularly, sometimes even 60 or 65 by some counts. However I started to notice about 5 years back that proportions of juvenile birds seemed low, and that has continued through this year.
There have been a few reports from other areas suggesting possible dispersal, but the numbers don't add up. 2 or 3 birds near Halsey, 3 or 4 at Finley, 1 or 2 at Ankeny, etc. We only had 8 or 9 Trumpeters as our peak count in southern Polk County this year, so the total count of Trumpeters in the mid-valley is way below the 40+ birds that would have been expected as recently as 5 years ago. My counts in recent years have generally been low.
Ten years back I remember seeing and hearing a flock of about 10 Trumpeters over Luckiamute State Natural Area, heading east toward Ankeny. So they got over there sometimes, but it was a day-trip kind of thing.
Bill Tice mentioned that some of their traditional habitat in southern Polk Co. has been fragmented by hazelnut orchards etc. That's certainly true but I'm not seeing Trumpeters in other places that they used in years past, which haven't yet been impacted by those same changes.
I hate to bring bird conservation topics into the discussion, but last week on NPR I heard a story about the Skagit Flats up in Washington, where biologists were expressing concern about lead ammo ingestion affecting Trumpeter Swans.
Good birding, Joel
On Wed, 2017-03-08 at 01:07 -0500, <obol...> wrote:
> Subject: [obol] Re: Trumpeter swans in the Willamette basin > From: Lars Per Norgren <larspernorgren...> > Date: Tue, 7 Mar 2017 11:24:43 -0800 > > * > > I got it backwards--I meant Halsey, which is the northern part of the > H pair, in Linn County. I think I've been to Harrisburg about twice in > my life. I recall the earliest reports from Halsey about 71/72 > involved a thousand Tundra Swans. Doug Robinson counted two thousand, > this winter maybe? Alpha-numeric collars on some of these birds show > that they sometimes visit Ridgefield NWR, Roy(Banks)in Wash. Co. and > Halsey w/in the same 30 day period. The last two winters I've seen > Tundra Swans west of Tangent, near the famous eagle roost. I didn't > three and four years ago when I was visiting the area frequently. > Tundra Swans began showing up on the central Oregon coast, Alsea > to Coos Bay, in the seventies, and their number grew modestly each > year before they disappeared completely. They were recorded on every > Coos CBC for well over a decade. Now they are absent from that count > for a decade at a time. I sort of expected something similar to happen > with these small spots of Trumpeters. > Lars > On Mar 7, 2017, at 11:04 AM, Bill Tice wrote: > > > Lars brings up a good point. It would be good to add that the > Airlie Swan flock is in all likelihood spreading out as their > territory is being infringed upon by new filbert orchards and grape > vineyards. This winter they have not been in that area as > consistently as in former years. Also, Lars may have been including > the swan flock now near Halsey in mentioning Harrisburg and there have > been reports via eBird of Trumpeters near Halsey this winter. Good > stuff. Maybe a whooper Swan will show up in the valley soon?????