Posted by: atowhee | November 27, 2015

ANNA’S’ INVASION

ANHUMALEfeedsThere has been a discussion of the Anna’s Humingbird’s range extension in Oregon.  Here are my two-cents-worth:

The rapid expansion of the ANHU range is just one example of what we should expect with climate change and habitat changes that will accompany.  In Jackson County it is now a common summer breeding species and the males over-winter.  Torpor allows them to survive the occasional really cold spells.

How fast are birds adapting?  In 1975 the Fish & Wildlife Service published a booklet summarizing all data on Jackson County birds.  The ANHU was described thus:  “an irregular and rare winter visitor and a regular uncommon summer visitor in the Lower Rogue River and Bear Creek valleys.”

Here are some recent CBC data from the county.  Medford ANHU totals from 2008 through 2014 are:13, 28, 16, 29, 14, 18, 31 (last winter was extremely warm in southern Oregon).

Ashland (where we started the count in 2010):  2010 thru 2014:  9-25-23-26-41.

Most of the Medford count is below 2000′ elevation and includes a lot of urban and suburban birding.  Most of Ashland’s count is above 1800′ elevation and goes up above 4000′.  It includes mostly ranch, pasture and forest land.  Not as quickly as the storied Collared-Dove, but the Anna’s conquest of inland Oregon is pretty impressive for such an imp.  It is our northern-most wintering hummer and getting more so.

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