Subject: re: boreal chickadees
Date: Jun 7 14:37:42 1994
From: Eugene Hunn - hunn at u.washington.edu


Jerry,

I've puzzled over that question for quite some time. You would think
there would at least be an appreciable movement of Boreal Chickadees to
low elevation feeders in the Methow, etc., but there are very few if any
such winter records. Note that Jewett et al. described the Cascade
Boreal Chickadees as a separate subspecies, distinct from those of the
Selkirks & the Canadian Rockies. Perhaps the Casdade population is a
small outlier that doesn't have the wherewithal to generate "invasions"
such as a regular back in the mid-west & east where the periphery of the
range is "fed" from a huge northern hinterland.

Gene Hunn. (hunn at u.washington.edu)

On Mon, 6 Jun 1994, Jerry Tangren wrote:

> On the discussion of boreal chickadees, why don't we encounter the
> phenomena of boreal chickadee invasions such as occur in eastern North
> America? Is the potential source of birds too small, the ecology of
> western forests different, or has the notion of invasions been
> overblown?
>
> Jerry Tangren
>