Date: 5/15/19 10:12 am
From: Matt Brady <podoces...> [Mendobirds] <Mendobirds-noreply...>
Subject: [Mendobirds] Re: Recent White-crowned Sparrow report
Hi Feather, Mendocino County has two eBird filters: one for the immediate
coast and one for the inland county. This is why things like Black
Oystercatcher, Western Gull, and Brandt's Cormorant do not appear on the
filter when you start a checklist for a Ukiah birding spot. I'm not sure
where the exact boundary is, but the coastal filter is pretty narrow, and
this checklist (https://ebird.org/view/checklist/S56238383) happened to
fall in the Inland filter. White-crowned Sparrows (subspecies 'nuttalli')
breed in a very narrow strip of coastal sage and chaparral along the
immediate coast, but are unusual even a mile inland during the late spring
and summer breeding season. So while White-crowns are expected along the
coast, this report is actually a little bit notable!

If you look at the eBird map for June and July (
https://ebird.org/map/whcspa?neg=true&env.minX=&env.minY=&env.maxX=&env.maxY=&zh=false&gp=false&ev=Z&mr=6-7&bmo=6&emo=7&yr=all&byr=1900&eyr=2019)
you'll notice that the vast majority of records fall within a mile or so of
the coast, but there are a handful of inland records in the county. Most of
them are undocumented, unfortunately, so it's hard to tell if they were
late or early migrants or entered in error. You'll also notice that there
are quite a few records from the coast range farther north, in Humboldt
County. A different subspecies, the 'pugetensis' subspecies, breeds there,
but it doesn't make it into the mountains of northern Mendocino County. A
third subspecies, 'oriantha' breeds in the Sierra Nevada.

Matt Brady
Baton Rouge LA (but formerly Potter Valley)

 
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