Thanks Mike—that’s why I mentioned that I already have WCSP here—and they’ve been here for three weeks at least. I’m in Oregon. So, for this year at least, I’m leaning towards an alternate migration route.
From: Mike Farmer [mailto:[email protected]] Sent: Friday, May 11, 2012 1:44 PM To: Caitlin Coberly; 'NFC-L' Subject: Re: [nfc-l] Austin, Tx - Listening stations - Through May 7, 2012 Caitlin, I think you are right. If a sparrow is going to migrate during favorable north winds in the fall in Austin, It is going to have to take advantage of fewer good days than if it wants to migrate north on the constant south winds of spring. You would expect the spring flight to be more constant. Not so many big big 1000 to 2000 call nights. As to the second question, here is a chart of the relative percent of sparrow calls for fall versus spring. I only have two seasons. But I started late in the fall season so I missed many sparrows and yet fall is still much bigger. Only CCSP seems bigger in spring yet the 2011 chart for the fall clearly shows that I started in the middle of CCSP migration. So I missed many. Of course, this assumes spring migration is over for sparrows. The seasonal checklists say yes. But maybe it’s late this year? Or they just migrate another way in the spring? As Mike says, it takes years of data to show anything. This could all just be within the sampling error. But perhaps someone out there knows something about sparrow migration that may explain it. -Mike Farmer From: Caitlin Coberly <mailto:[email protected]> Sent: Thursday, May 10, 2012 10:15 PM To: 'Mike Farmer' <mailto:[email protected]> ; 'NFC-L' <mailto:[email protected]> Subject: RE: [nfc-l] Austin, Tx - Listening stations - Through May 7, 2012 Mike-- A couple of questions: 1) The Sparrow migration is steadier in spring. Or is it that you have had nearly constant winds this spring? Are the winds nearly always more constant in spring? 2) Are WC and WT SP using a different migration path? Where have they shown up? I have WC here already—as of 3 weeks ago. No WT, but they don’t occur here. Totally cool plots. Thank you! From: [email protected] [mailto:[email protected]] On Behalf Of Mike Farmer Sent: Thursday, May 10, 2012 3:01 PM To: NFC-L Subject: [nfc-l] Austin, Tx - Listening stations - Through May 7, 2012 Well, the most fascinating thing about any new hobby is the surprises that occur. And this one is no different. We first started recording on Sept 29th of last fall. We had missed most of the fall migration by starting so late. Except we got a truly huge sparrow migration that came down after each north front. Several times, nights with 1000 to 2000 calls were recorded. So we were so sure that we would get 1000s upon 1000s in the peak of spring. Well, not quite. Instead we have just recorded a steady rise in more and more birds on each night with favorable south winds as we went toward and now through the peak of migration. No night at any one of three stations giving more than 500 calls. And the peak of migration seeing a steady 200 to 350 a night for a period of 7 straight days. The sparrow migration is steadier in spring. Not so erruptive, it seems. But where are the White-crowns and the White-throated? I guess they decided not to migrate back this year. We have almost no WTSP this spring. And only 10% of the WCSP fall migration. And not near as many CHSP as occurred in fall. Or VESP, for that matter. Maybe they are still to come? It’s inscrutable. Do they take another path north? The attached graphs show what it’s like to migrate in spring through Austin as a sparrow. They are remarkably smooth graphs when looking at each species as a proportion of each day’s flight. Each species with enough samples would seem to fit a bell-shaped curve just fine. Or maybe a left or right skewed one at least. Especially if the north wind nights with small flights are removed from the data. -Mike Farmer equipment Mic – Oldbird 21c Software – Oldbird tseep, thrush, GlassOFire, Raven Pro, Excel -- NFC-L List Info: <http://www.northeastbirding.com/NFC_WELCOME> Welcome and Basics <http://www.northeastbirding.com/NFC_RULES> Rules and Information <http://www.northeastbirding.com/NFC-L_SubscribeConfigurationLeave.htm> Subscribe, Configuration and Leave Archives: <http://www.mail-archive.com/[email protected]/maillist.html> The Mail Archive <http://www.surfbirds.com/birdingmail/Group/NFC-L> Surfbirds <http://birdingonthe.net/mailinglists/NFCL.html> BirdingOnThe.Net Please submit your observations to eBird <http://ebird.org/content/ebird/> ! -- -- NFC-L List Info: http://www.NortheastBirding.com/NFC_WELCOME http://www.NortheastBirding.com/NFC_RULES http://www.NortheastBirding.com/NFC-L_SubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NFC-L 3) http://birdingonthe.net/mailinglists/NFCL.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
