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 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/ --
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