How does this affect sage sparrow distribution?

Cheers,
Paul Duval

On Wed, 16 Apr 1997 steppie at wolfenet.com wrote:

> Sage Thrashers are indeed locally distributed in the Columbia Basin.Height
> of sage in my opinion, is not so much a factor, for this species is common
> in the very dwarfish (less than 24" high) 3-tip sage communities on north
> and east slopes on the Yakima Training Center. What is important is
> vegetation structure. Native grasses (Poa, Agropyron) supply this critical
> structure. Shrub density is needed, but not height. In lowest and driest
> parts of the basin, native grasses are rare-introduced cheatgrass seems to
> have gained a permanent place there, at the expense of native grasses. In
> higher and wetter parts of the basin, native grasses have persisted in more
> locales, even with grazing. This is particularly true on north slopes. Sage
> Thrashers have maintained good populations in these areas.
>
> This notion of vegetation complexity in the shrub-steppe zone is analgous to
> the complex structure found in old-growth forests. Reduce or eliminate this
> highly varied structure and a reduction in bird and other animal species
> dependent on that complexity decline or disappear.
>
> Andy Stepniewski
> Wapato WA
>
>