Thank you for this interesting post Chris. This has been a dominate topic of discussion among many birders in the Adirondacks. Sean O'Brien and I have been talking every few days wondering what has happened to many neotropical migrants this year. I mentioned the low numbers of Blackpoll Warblers and Yellow-bellied Flycatchers on Whiteface Mountain in my earlier post today, but numbers of most neotropical migrants appear way down. Sean keeps remarking that there is no dawn chorus this year. Even my non-birder husband has been noting the lack of birds this spring. Normally, you can't sleep past 4:30 a.m. in our house at this time of year because of the remarkable dawn sounds outside our bedroom window, but it feels more like late summer every morning with the lack of songs. I was aware of the weather-related fallout on the Gulf Coast of Texas in April, and I had to wonder, with so many birds too exhausted to be afraid of humans, how many may have perished unseen over the Gulf?
Migration seemed highly unusual this year. Normally, species like Blue-headed Vireo would suddenly fill the forests overnight. This year, I found ONE, and then a week went by and I found a second one, then several days went by and they began to arrive in a trickle. Species were, for the most part, late arriving and they trickled in. We have been waiting for the forests to fill, but it hasn't happened and it is now June 4th. In a section of Massawepie Mire that is normally filled with breeding Canada Warblers, we heard one on Saturday. It is definitely worrisome. As you mentioned, BBS surveys may help document the apparent population declines. Thanks again for your thoughts about possible reasons for such worrisome declines. I too, would be interested to hear the thoughts of other birders on this topic. Joan Collins Long Lake, NY From: bounce-98052797-13418...@list.cornell.edu [mailto:bounce-98052797-13418...@list.cornell.edu] On Behalf Of Christopher T. Tessaglia-Hymes Sent: Tuesday, June 04, 2013 12:18 PM To: NYSBIRDS-L Subject: [nysbirds-l] Fwd: Minimal Migration or Population Decline? 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 <nf...@list.cornell.edu> 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_warbl ers_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: <http://www.northeastbirding.com/NYSbirdsWELCOME> Welcome and Basics <http://www.northeastbirding.com/NYSbirdsRULES> Rules and Information <http://www.northeastbirding.com/NYSbirdsSubscribeConfigurationLeave.htm> Subscribe, Configuration and Leave Archives: The Mail Archive <http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html> <http://www.surfbirds.com/birdingmail/Group/NYSBirds-L> Surfbirds BirdingOnThe.Net <http://birdingonthe.net/mailinglists/NYSB.html> Please submit your observations to <http://ebird.org/content/ebird/> 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/nysbirds-l@cornell.edu/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/ --
