Hi All, I forgot to mention that the link I provided for Cochran's work is for the transmitters he is using but it talks about a different project. For the acoustic study he analyzed the same channel for calls instead of counting wing-beats. These transmitters have 2 channels, one a tracking signal and the other the audio stream.
Mike Michael Lanzone [email protected] On Fri, May 11, 2012 at 11:26 AM, Michael Lanzone <[email protected]>wrote: > Jessie and Mike, I will answer both of your posts in more detail later > when I have time, but to my knowledge there has only been one person to > collect definitive data on call rates of birds during nocturnal migration > (from know individuals). It was on was on Swainson's Thrushes where he had > a transmitter attached to it during nocturnal migration transmitting back > to a vehicle to be recorded via radio. I saw a partial manuscript on this > several years ago, I hope it gets published, its an invaluable study. Here > is a short excerpt from Cochran's study- > http://www.inhs.illinois.edu/inhsreports/sep-oct97/migrants.html > > One of the published papers out there dealing with this is the Farnsworth > et.al. paper- "A comparison of nocturnal call counts of migrating birds > and reflectivity measurements on Doppler radar" > > Mike > > Michael Lanzone > [email protected] > > > > > On Fri, May 11, 2012 at 11:14 AM, Mike Farmer <[email protected]> wrote: > >> Thanks everyone....I wish there was a central place for all your >> knowledge for us newbies to peruse. It would make getting started >> easier....but maybe less fun in the floundering? >> >> I’ve had this discussion with a bunch of people just starting to record >> or who have given up after attempting to record. It seems to be a >> naturally progression that newby’s like myself take. First, we are amazed >> at how well the detectors will find such small packets of energy above the >> background noise. Then we go into near depression because a beautiful OVEN >> bird zeep is some how missed. Then horror that my big night of 500 calls >> could have been 750 if I would just wade through 20,000 false positives >> instead of 3,000. >> >> The OLDBIRD detectors and Raven Pro detector....to name the only two I >> have used....are amazing detectors. State of the art for what they do. >> But the background noise is varying so rapidly and randomly that some calls >> are missed and false detection are many. >> >> It is at this point that the newby must decide. What am I trying to >> do? For me, I finally realized that I want as unbiased a sample of the >> birds calling over my house as I can get and I want a sufficient sample. >> A good number, that is. I’m not so concerned that I get every call that >> my mic hears as long as I don’t miss OVEN birds at a higher rate than CCSP, >> for instance. But I also don’t want just 10% of the calls because >> although that may be good enough for the many CCSP, it may not be enough >> OVEN birds calls to analysize. >> >> Notice that I said that I want an unbiased sample of the birds >> calling.....not that I am getting an unbiased sample of the birds flying >> over my house. Sure, I would want that but apparently you professionals >> haven’t even determined what the call rate of each species is. So we >> newbies have to realize that we are in no way counting how many birds fly >> over our house. Right? Do I have that right? >> >> But when I read your professional papers and talk to the gurus like BIll >> Evans, I see that we can talk about changes in the proportion of the calls >> of each species. At least until you professionals give us more ways to >> crunch the statistics. >> >> Sorry for the mini-rant. I think newbies should be less frustrated by >> missed calls than we just naturally seem to be. The pursuit of perfection >> should not be the enemy of the good. >> >> -Mike Farmer >> -Oldbird and Raven Pro detectors are great....newbies, use them! >> >> *From:* Lewis Grove <[email protected]> >> *Sent:* Friday, May 11, 2012 8:26 AM >> *To:* Andrew Albright <[email protected]> >> *Cc:* Mike Farmer <[email protected]> ; NFC-L <[email protected]> >> *Subject:* Re: [nfc-l] Austin, Tx - Hourly count - Through May 7, 2012 >> >> Hi Andrew and all, >> >> Automated detection of calls is a tricky business, though it is >> relatively easy to figure out the proportion of calls that you are actually >> pulling out - just count calls manually, screen by screen and then see how >> many your detectors find. We looked at 90 different random 15-minute >> segments from three different recording sites, using multiple observers to >> find the total number of calls present. >> >> Basically, depending on the software package and the parameter >> combinations you use (SNR and occupancy are the big ones other than having >> your time and frequency bounds correct), you can get wildly different >> proportions, ranging from near zero to near 100% of calls. I can't >> remember the exact numbers but I believe Tseep-x finds something just shy >> of 50% of the warbler/sparrow calls present in a file. Other factors come >> in to play here too - background noise (insects) particularly. >> >> Hopefully all of this data (there's a lot) will someday see the light of >> day in a journal - it's overdue. >> >> Lewis >> >> >> On Fri, May 11, 2012 at 8:19 AM, Andrew Albright < >> [email protected]> wrote: >> >>> 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/ >>> >>> -- >>> >>> >> >> >> -- >> Lewis Grove >> PhD Student, Wildlife Ecology >> President, Graduate Student Association >> SUNY *E*nvironmental *S*cience and *F*orestry >> (814) 880 - 5667 >> >> >> -- >> *NFC-L List Info:* >> Welcome and Basics <http://www.northeastbirding.com/NFC_WELCOME> >> Rules and Information <http://www.northeastbirding.com/NFC_RULES> >> Subscribe, Configuration and >> Leave<http://www.northeastbirding.com/NFC-L_SubscribeConfigurationLeave.htm> >> *Archives:* >> The Mail Archive<http://www.mail-archive.com/[email protected]/maillist.html> >> Surfbirds <http://www.surfbirds.com/birdingmail/Group/NFC-L> >> BirdingOnThe.Net <http://birdingonthe.net/mailinglists/NFCL.html> >> *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/ --
