> ** Steve wrote -
> >
> > Fair enough, however still, they're intelligent birds, and my understanding
> > is that most of the Westward movement appears to be up north of the great
> > plains and in Canada. The planting of trees in the Great Plains should
> > have nothing to do with that. I would think that the plantings would
> > accelerate the Wesward migration further South.
>
> Bingo. We are forgetting our physiogeography. The Great Plains extend only
> marginally northward into Canada, mostly into s. Saskatchewan, and only a bit
> into s.e. Alberta and s.w. Manitoba. The jays are not using the plains as a
> conduit. They are using the vast belt of boreal forest rimming the northern
> edge of the prairie which starts in s.e. Manitoba, cuts across c. Saskatchewan,
> and extends into n.c. Alberta, n.e. BC, and extreme s.e. Yukon. So Steve is
> correct. Note also that this is likely to be a unispecies movement - there is
> simply not enough of the dense coniferous forest favoured by Steller's Jays
> to entice them very far east of the Rockies, IMO.

Wow, and I never even studied physiogeography! I just looked at a map...
;-)

Steve Mansfield steve at nwnet.net
NorthWestNet Network Engineer 425-649-7467