Hi All, We do occasionally pick up robins on some of our recordings, but they are few and far between in the night hours (pre 3am) and that is on well over 20k hours of recordings here and in the Appalachians. I tend to hear many more from 3-5am. However, on several occasions here I have observed (visually) on top of Laurel Ridge in PA and Backbone Mtn and Allegheny Front in MD and WV robins during the middle of the night, one time 100s of them flying low in the middle of the night. They were largely silent, I may have heard ~5 calls of 5-600 birds, but may have certainly masked by the high calling rate that night. These birds were forced low because of fog and there was a heavy flight those nights with a lot of flight calling activity, and these spots were lighted and I could readily ID many of the birds coming over with binoculars and naked eye. Almost all of our recording stations are not lit and we purposely do not record in lighted areas as that does inflate call rates, however it would be interesting to compare some of these locations with the darker ones, a study that I had talked about last year, possibly by this fall I can get a few more stations online to do such a comparison. I wonder if robins either call less nocturnally, fly much higher, coastal effects cause a higher calling rate and/or their calls are softer and may be masked by thrushes.
Best, Mike Michael Lanzone Biotechnology and Biomonitoring Lab Supervisor Carnegie Museum of Natural History Powdermill Avian Research Center 1847 Route 381 Rector, PA 15677 724.593.5521 Office [email protected] On Tue, Apr 6, 2010 at 4:34 PM, Jeff Wells <[email protected]> wrote: > Maybe but you would think that under certain conditions with low cloud > cover, etc., that over the years I would have picked them up. Maybe it is > one of those things that happens more often late and early in the year when > I am not recording as much….. > > > > Jeff > > > > *From:* Michael O'Brien [mailto:[email protected]] > *Sent:* Tuesday, April 06, 2010 4:29 PM > > *To:* Jeff Wells > *Cc:* [email protected] > *Subject:* Re: [nfc-l] Night flight call station results-Maine-April 1-3 > > > > Maybe the robins over your station are typically too high to be heard in > the middle of the night. Just a thought. > > > > Re terns, I have also only herd Caspian. I have heard them both spring in > and fall inland, but I don't recall ever hearing them along the coast. > > > > Michael > > > ----- Original Message ----- > From: "Jeff Wells" <[email protected]> > To: "Michael O'Brien" <[email protected]> > Cc: [email protected] > Sent: Tuesday, April 6, 2010 4:08:38 PM GMT -05:00 US/Canada Eastern > Subject: RE: [nfc-l] Night flight call station results-Maine-April 1-3 > > Very cool! Makes sense when you see large numbers of robins flying over in > the early morning hours that they would be birds that have been moving at > night. Funny though that over the years I don’t recall picking up any within > the 10 PM-2 AM window that I think of as indicating birds moving through the > night as opposed to in the early morning hours when it is not as clear > whether they just started migrating or are descending. > > > > Speaking of birds that move through the night but are not as readily > detected, have any of you picked up terns other than Caspian Tern migrating > at night? It’s obvious that they migrate at night based on the way they just > appear one morning in a location but it seems like you don’t hear them. > Though at least Caspian Terns in the fall when they have still-dependent > young regularly call back and forth with the trailing young birds at night. > > > > Jeff > > > > *From:* Michael O'Brien [mailto:[email protected]] > *Sent:* Tuesday, April 06, 2010 3:59 PM > *To:* Jeff Wells > *Cc:* [email protected] > *Subject:* Re: [nfc-l] Night flight call station results-Maine-April 1-3 > > > > Jeff, > > > > I'm interested in your assertion that American Robin is strictly a diurnal > migrant. Perhaps that is true in some areas, but in Cape May it certainly is > not. We regularly see massive American Robin flights at night, in fall at > least. These flights often continue or resume in the first few hours of the > morning and again in the last hour or so of the day. During particularly > heavy flights, the movements may continue longer into the day, but my > estimation is that the bulk of the movement always takes place at night. I > find their behavior to be much like that of Bobolink, only they seem to be > less vocal. It would be interesting to know what others have observed and if > the situation is different elsewhere. My guess is that the main difference, > if any, is that robins call more frequently in certain situations and fly > more quietly in others. > > > > good listening! > > Michael O'Brien > > > > > ----- Original Message ----- > From: "Jeff Wells" <[email protected]> > To: [email protected] > Sent: Tuesday, April 6, 2010 2:42:45 PM GMT -05:00 US/Canada Eastern > Subject: [nfc-l] Night flight call station results-Maine-April 1-3 > > I started my automated recording station for the season here in Maine on > Thursday night, April 1st. Although there were few calls each of the last > three nights, the numbers increased a little each night from about 10 the > night of the 1st to about 30 last night. There were a few Hermit Thrushes > the first night, 6 the 2nd and 12 the night of the 3rd. There were a few > Killdeer each night, a Wood Duck, and 4-10 sparrows each night with Song and > White-throat plus a couple that may be American Tree Sparrow and a junco or > two. A few other items of interest: > > > > -several nights had Herring Gull calls in the middle of the night that I > assume are night migrating birds; > > > > -several nights had the squeal flight calls of American Robins around > midnight. Although I sometimes have what I assume to be local on-the-ground > robins sing and give ground alarm calls in the middle of the night, they > don't give the squeal calls. The acoustics of the recorded squeal calls also > seem more like birds overhead. I suspect that, as unlikely as it seems, that > these were night-flying robins when by all accounts the species is only a > diurnal migrant; > > > > -one night I had what sounded like a bit of song of a night-flying Hermit > Thrush. I typically get some night-flying birds in May that break out in > song or partial song while flying overhead but I had never picked that up > for Hermit Thrush. > > > > I posted some of the call files on my blog at: www.borealbirds.org/blog > > > > Jeff Wells > > > > > -- NFC-L List Info: http://www.NortheastBirding.com/NFC_WELCOME http://www.NortheastBirding.com/NFC_RULES ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://birdingonthe.net/mailinglists/NFCL.html 3) http://www.surfbirds.com/birdingmail/Group/NFC-L Please submit your observations to eBird: http://ebird.org/content/ebird/ --
