Mike - I enjoy reading your reports, so keep 'em coming! I'm no expert, but I think when I asked the question before it seems that the general idea is that nfc are easier to detect in the first couple of hours and then around dawn as birds will be flying at lower elevations (and they can get so high that you can't detect nfc). But I don't know how much data supports this hypothesis and it's quite possible that it's from East Cost migration which could be significantly different from that seen in Texas.
I have one question - have you ever gone through an hour or a night of your data to see/hear how well the automatic detection works? Also, what % of nfc can you not assign to a certain species? Sincerely, Andrew On Thu, May 10, 2012 at 4:15 PM, Mike Farmer <[email protected]> wrote: > Since March 1, our Austin city station has recorded 4250 night calls. The > quieter station 10 miles to the west had 6372. See the attached graph > showing the number of calls per hour of the night. This is for the quiet > station. > > This chart seems rather too convenient. I am suspicious of it. What is > known about this kind of timing? The curve matches the inverse of the > relative quiet of a typical night. Life is just quieter in the middle of > the night. So can’t a lot of this be a detector and noise effect? Or do > the birds actually fly and call more in the middle of the night? > > Also this data doesn’t adjust for daylight savings shift in the third week > of March or the fact that dusk shifts to later times as spring progresses. > What we really want to plot is the hour after dusk not the actual time. But > has anyone here figured out a formula for the number of minutes each night > that dusk shifts? You can google this and get a bunch of graphs but there > must be a formula ..... probably involving a bunch of cosines and other > witchcraft? > > -Mike Farmer > > > equipment > > Mic – Oldbird 21c > > Software – Oldbird tseep, thrush, GlassOFire, Raven Pro, Excel > > -- > NFC-L List Info: > Welcome and Basics > Rules and Information > Subscribe, Configuration and Leave > Archives: > The Mail Archive > Surfbirds > BirdingOnThe.Net > Please submit your observations to 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/ --
