Date: 2/19/18 5:52 am From: Lars Per Norgren <larspernorgren...> Subject: [obol] Re: American Robin migration
I've lived just inside the Coast Range forest for 25 years, 25miles
nw of Portland. I notice that Robins cease to be present here in
late October and reappear in late February. I used to think it was
an extremely local event. Then some posts on Obol a year or two
ago made me realize it is all over the NW . In 2002 I drove to Wallowa
Lake at this time of year and spent the weekend there. There were
Robins there, simultaneous to my home 350 miles to the west.
There was a Robin at our house one day in January this year,
but today (2/19) there is plenty of snow. lpn
On Feb 19, 2018, at 12:15 AM, Nathaniel Wander wrote:
> I too noticed robins on my NW Portland patch this afternoon for the first time since fall.
> I'm not sure exactly how this works out in terms of who ends up breeding where, but I believe that American Robins are leap-frog migrators. That is to say, northernmost populations over-leap middle latitude ones in to travel to their wintering grounds and middle-latitude breeders similarly over-leap the most southerly breeders.
> Nathaniel Wander
> Portland, OR
> Max Planck is supposed to have said:
> A new scientific truth does not triumph by convincing its opponents and
> making them see the light, but rather because its opponents eventually die
> and a new generation grows up that is familiar with it.
> Andreas Wagner observed of Planck's remark:
> Science, like nature, advances one funeral at a time. (Arrival of the Fittest, p.197)