The gap is one of habitat choice. Allen's seem to prefer drier coastal
scrub, Rufous wetter, greener places. Allen's is only confirmed as breeding
in Curry Co. on the extreme southern Oregon Coast where the habitat is
most similar to California. I am told that one of the ways to distinguish
Allen's and Rufous in the breeding season in California is by habitat.

It's the notch in the tail that gives Rufous it's distinctive chatter
at the bottom of its dive.

>
>Mike,
>
>What still puzzles me is whether there is a gap in the breeding range of
>Selasphorus hummers on the Oregon coast and, if so, just where it is. My
>impression is that Rufous Hummers are common nesters all along the
>Washington coast.
>
>Also, the contrast between the chattering squeal of Rufous and the whine
>of Allen's. Could it be due to the sharpness of the angle that Rufous
>Hummers make at the bottom of their dive versus the shallower pendulum
>curves on Allen's? Or is it due to some structural difference.
>
>Gene Hunn.
>

--
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* Mike Patterson, Astoria, OR * God abhors a naked singularity
* mpatters at ednet1.osl.or.gov * S.Hawking
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