Evan Centani's Observation of Swans at Ankeny got me to wondering.
There have been Trumpeter Swans in the vicinity of Airlie every winter since
the mid-seventies. Ankeny NWR is very nearby, yet I'm not sure I've ever read a
report of Trumpeters from there. It seems like small numbers of Trumpeters are
now being reported from Finley, more than two but less than half a dozen,
suggesting a single family. The large flock of Tundra Swans at Harrisburg has
been wintering there since at least the early 70s, yet I've never read of a
Trumpeter among them.
Maybe some of this is an artifact of observer effort and opportunity. The
swans at both Airlie and Finley can on occasion be observed at very close
range. When hundreds of swans are visible a mile away at Sauvie Island, there
is little incentive to give them close scrutiny. A family sized group of
Trumpeter Swans has been reported off and on in the general vicinity of Forest
Grove for decades, and I believe folks have seen them around the former Trojan
nuclear power plant, a place that is seldom mentioned on Obol. I'm struck by
the stability of these small numbers. Over the decades the Trumpeters have
neither gone up in numbers, nor disappeared.
Lars
