John, I recall a post on this list serve a few years back (Mike Lanzone in PA?) where it was mentioned that Savannah Sparrows were a common NFC, but were rarely encountered on the ground. I suspect given the diversity of habitats that our migrants use, it would be really tricky to make direct comparisons because your ground counts are so dependent on the habitat you are in. But it might work for certain species that you sample well on the ground, as you say. And of course, something like eBird that compiles observations across sites (and skill levels, and all the other biases of bird watching), starts to get at a more regional picture of what is expected when. I like the idea of probabilistic identification (and FYI, Ted Floyd blogged about this on his ABA blog a couple months back - interesting concept). Maybe eBird contains the "prior" that one needs to generate probabilities around flight call complex "identification"?
Erik Johnson S Lafayette, LA ejohn33 AT lsu.edu ejohnson AT audubon.org On Thu, Sep 20, 2012 at 11:07 AM, John Kearney < [email protected]> wrote: > The discussion today reminds me of a similar train of thought that I’ve > been pondering lately. Namely, in today’s world of birding and ornithology, > we require a high of degree of certainty when it comes to documenting the > classification of our observations to the species level. Basically, > photographic proof has become almost essential for rare species. When it > comes to night flight calls, the certitude of species identification > becomes very problematic. I am concerned that we might apply similar > standards to NFC identification as to bird observations. Should we rather > think of NFC IDs more in terms of probabilities and error bars than > certitude? I personally feel this approach is worth pursuing if we wish to > make more of a contribution to bird migration and aeroecology. For example, > where I in live in Nova Scotia, the “zeep” warblers can be boiled down to > about 6 species that are difficult to identify. Thus while I might not be > able to distinguish the NFC of a Yellow Warbler from a Blackpoll Warbler, > it is very probable that this type of call in early August is a Yellow > Warbler and such a call in early September is a Blackpoll Warbler. This > breakdown of all the zeep warblers into probability categories is much more > useful, I believe, for understanding regional migration patterns than > having them all lumped as zeep warblers because we can’t be certain of > their identification to the species level. How we calculate these > probabilities is another question. I have been doing stop-over transects in > areas close to a recording station. Although this analysis is not > completed, I sense that there may be some interesting correlations to be > made between the species composition of nocturnal migration and stop-over > areas within a certain time frame.**** > -- > *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/ --
