Tuesday, November 11, 2014

Map Monday: Pilot Test

In an effort to revitalize this ailing blog, I'm going to try out a series of posts exploring bird distribution. I plan to post a nugget every Monday.

Let's talk about Varied Thrushes. They're cool, right? Correct answer: right. Basically, someone took an American Robin, spiffed it up with Arabian geometric designs, and replaced its jolly song with a haunting New Age whistle. Oh, and instead of lawns, Varied Thrushes inhabit fog-shrouded coastal forests. Doesn't get much cooler than that.

It so happens that this is shaping up to be an above-average year for wintering Varied Thrushes in southern California. Normally, SoCal represents the southern tip of the thrush's winter range. Orange County is blessed by perhaps one Varied Thrush in the average winter. At least ten have been spotted in the county so far this season. In the words of Doug Willick, 2014-2015 may be "one of the best flight years in memory" for Varied Thrushes in southern California.

First, let's look at a classic range map, swiped from BirdFellow.com.

Now, the analogous map from eBird. The most significant difference is the eastern occurrences--Varied Thrush is not unprecedented in the winter in the East, but it is by no means regular or expected.

Next, an eBird map showing the breeding range. The core of the breeding range seems to be British Columbia and southern Alaska. Central California (i.e., Big Sur region) seems to be the southern tip.

Next, the winter range (sightings from October through March).

And finally, a map of southern California showing individual sightings of Varied Thrush. The red pins are sightings from the last month. Many are already appearing in the coastal plain!

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