Chris and Joan speak of what many of us have individually observed and then discussed in passing in the birding trails this spring. I'm sure, as we write, there are doctoral candidates and others near the posting areas, who are awaiting data from this May, and will give us the broad analysis we want. A great source for the raw data is, of course, eBird. This discussion highlights the importance of each of our accurate reports to ebird. While we all hope that somehow the apparent absence of birds in Joan's -- and the rest of our -- usual spots, can be explained by an increase of birds in other locations, the data, good or bad, can help us help the birds. That is, legislators/policy makers love numbers and can use them as tools for change, positive change of many kinds. Either way, being part of a citizen-science venture like ebird, whether recreational birder or professional is good for the birds we all love. Looking forward to reading those dissertations and papers. Good birding and good reporting! David Staten Island
On Jun 4, 2013, at 12:18 PM, "Christopher T. Tessaglia-Hymes" <[email protected]> wrote: > Good afternoon! > > This morning, I sent the following email to NFC-L, the Night Flight Call > eList, and thought some on NYSbirds-L might find this of interest or have > some input. > > Sincerely, > Chris T-H > > Begin forwarded message: > >> Date: June 4, 2013 9:46:52 AM EDT >> To: NFC-L <[email protected]> >> Subject: Minimal Migration or Population Decline? >> >> Good morning, >> >> I am curious to know if recording stations in the Northeast have >> experienced, numerically – with respect to quantity of night flight calls, a >> reduced number of migrants this spring as compared to past years. My >> perception is that there was a noticeable lack of birds moving throughout >> certain regions of the Northeast this spring. Conversely, did recording >> stations elsewhere (perhaps in the mid-west) record higher numbers of >> migrants this spring? >> >> On the ground, for example, I don't ever remember a year when I only heard >> or saw 2-3 Blackpoll Warblers. Period. Usually, I would hear or see several >> Blackpoll Warblers on any given day over the course of a few days during the >> peak movement for this species. Of course, maybe a mass die-off of Blackpoll >> Warblers and other migrants went unnoticed this past fall or this spring, >> similar to the infamous mass die-off from 2-3 October 2011 at the Laurel >> Mountain wind facility in West Virginia. See: >> http://www.birdfellow.com/journal/2011/10/29/in_the_news_484_blackpoll_warblers_die_at_wind_farm. >> Note: it is suggested these birds succumbed to exhaustion from becoming >> trapped in the sphere of fog-reflected light produced by a lighted >> substation, which was accidentally left on overnight at the facility, rather >> than actual deaths caused by direct turbine strikes. >> >> I know there was a memorable weather-related fallout on the Gulf Coast of >> Texas this past 25-27 April 2013. See: >> http://www.texasbirdimages.com/home/2013-fallout---cameron-county/nueces-co-list---april-25-2013. >> It makes me wonder if it is at all possible for unfortunately-timed severe >> weather-related events, during key trans-Gulf crossings, to result in >> population-wide declines of neotropical migrants. >> >> Or, is this just an anomalous year as a result of the negative phase of the >> North Atlantic Oscillation, producing unfavorable conditions for nocturnal >> movement of small passerines into the Northeast. In possible scenarios like >> this, do boreal neotropical migrants favor an alternate springtime route >> that may carry them North, up the Mississippi Flyway to a point North of the >> Great Lakes, allowing them to then catch the prevailing West wind in an >> Easterly direction to their breeding grounds? If such a scenario were to >> play out, how do first spring individuals learn of these routes? Do they >> follow the masses? >> >> Interestingly, I'm finding that the cuckoos seem most unaffected by minor >> Northerly airflow at night (such as the night of 2-3 June). I'm sure their >> body size and wing length have everything to do with the ability to migrate >> into a headwind as compared to smaller passerines, such as warblers. Last >> night, in calm to light winds, I recorded 7 different Black-billed Cuckoos >> and a single Yellow-billed Cuckoo, plus a single Virginia Rail, one Alder >> Flycatcher, one Swainson's Thrush, and a single Indigo Bunting. >> >> Unfortunately, I was not recording sooner this spring in Etna, NY, so don't >> have a good comparison of this year to last year (for peak migration); >> however, I did get out as much as possible to a migrant stopover patch on >> most mornings (see the Hawthorn Orchard: >> http://www.birds.cornell.edu/cayugabirdclub/hawthorn.htm and check eBird for >> this site). My perception from daytime observation was a serious lack of >> neotropical migrants, yet with a reasonable amount of resources (insect >> larvae) for them to feed upon. This was one of the more memorable >> springtimes for me, with respect to flowering trees. I don't recall a time >> in the recent past of a springtime with the same amazingly full quantity of >> flowers remaining on the trees for as long as they did, yet with so few >> migrants. Though, perhaps in actuality there may have been fewer food >> resources (insect larvae) available than in past years, due to the cooler >> weather this spring (in the Northeast). >> >> If weather conditions correlate as closely to food resource availability as >> is probably the case, perhaps the birds use weather-related cues to avoid >> migration routes that may lead through regions with a dearth of food >> resources as compared to routes through other regions with high food >> resources. Or, perhaps there was a mass die-off in the Gulf this spring or >> the Atlantic and/or Gulf last fall, or at nighttime lighted facilities on >> unfortunately fog-enshrouded nights. It all seems so speculative without >> looking at long-term population trends in different regions. I think it will >> be interesting to watch for the comparative results from this year's >> Breeding Bird Surveys to past Surveys and of Surveys to come in future >> years, as well as the gradual accumulation of records in eBird. >> >> Thanks for any thoughts and input on this! >> >> Sincerely, >> Chris T-H >> >> -- >> Christopher T. Tessaglia-Hymes >> Field Applications Engineer >> Bioacoustics Research Program, Cornell Lab of Ornithology >> 159 Sapsucker Woods Road, Ithaca, New York 14850 >> W: 607-254-2418 M: 607-351-5740 F: 607-254-1132 >> http://www.birds.cornell.edu/brp > > -- > Christopher T. Tessaglia-Hymes > Field Applications Engineer > Bioacoustics Research Program, Cornell Lab of Ornithology > 159 Sapsucker Woods Road, Ithaca, New York 14850 > W: 607-254-2418 M: 607-351-5740 F: 607-254-1132 > http://www.birds.cornell.edu/brp > > -- > NYSbirds-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! > -- -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birdingonthe.net/mailinglists/NYSB.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
