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 19735 the Fish & Willife Service published
a bookley summarizing alldata 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.
On Thu, Nov 26, 2015 at 5:24 PM, L Markoff <canyoneagle@xxxxxxxxxxx> wrote:
Regarding Anna’s Hummingbird range expansion, some of you might have
interest in a new study being done in nearby Idaho.
http://ibo.boisestate.edu/winter-hummers/
Lori Markoff
Eugene (South Hills)
