Shai, Thank you for the dive into your bookshelves.
For those who are away from the libraries :), or don’t have back issues of North American Birds, you can go to the SORA site (Searchable Ornithological Research Archive) maintained by the University of New Mexico (sora.unm.edu). Many ornithological journals, including North American Birds are available there as pdfs. The issue Shai cites is among them and the bird in question is also discussed in the Seasonal Highlights section, as well as a color photo in the Pictorial Highlights section as well as the page Shai references. Joe DiCostanzo Sent from my iPad > On Jun 15, 2018, at 3:12 PM, Shaibal Mitra <shaibal.mi...@csi.cuny.edu> wrote: > > Swore I wouldn't do it, but I just pulled my stacks of North American Birds > off the shelf. > > The NJ bird was photographed at Stone Harbor, near Cape May, by Michael > O'Brien on 14 Jul 2003, and reproduced in Volume 57, p. 473 of North American > Birds. The caption reads, "One of the most interesting birds of the season to > be documented in the [Hudson-Delaware] Region, indeed one of the most > intriguing in many years, was the apparent longipennis Common Tern, a > Siberian nester never before recorded in the Atlantic basin, which was > studied carefully at Stone Harbor Pt. 14 Jul (ph. MO'B, m/ ob.). Old World > authorities have reviewed the series of photographs by O'Brien and concur > with the identification as longipennis, probably a bird in its second summer." > > The RI bird was around that time, and it is possible that I conflated it with > the NJ bird vis a vis the NAB photo, but I've put in the call to an observer > of that bird (which was definitely well photographed) to pin it down, too. > > Shai > ________________________________________ > From: Shaibal Mitra > Sent: Friday, June 15, 2018 2:23 PM > To: NYSBIRDS (NYSBIRDS-L@cornell.edu) > Subject: RE: [nysbirds-l] Dark billed, dark legged Common Terns on Long Island > > Again, nobody is saying we know for sure what these birds are. But those who > know the most about the records in question find them intriguing, and, having > studied variation in hirundo collectively with great interest for many > decades, remain uncomfortable with that null hypothesis. Another hypothesis > that people have offered is hirundo x Arctic Tern hybrid; genetic > incompatibility might result in deviations in various traits associated with > normal breeding condition. Another possibility (which could account for the > oddity that most/all have been "second-summer types" (based on white in the > forehead, mottling on the underparts, and atypical primary replacement > pattern) is that just a couple of birds have been rattling up and down the > Atlantic and have gotten old and lonely. > > The cool thing about the better candidates is that they would absolutely > stand out from hirundo in multiple ways, even if their bills and legs were > colored exactly like typical hirundo: > > They are long-winged--as judged relative to their bodies, resembling Arctic > Tern in this way > They are very long-tailed--at least one with tail streamers extending beyond > the tips of their already relatively long wings > They are intensely gray below--more intensely gray than even high breeding > hirundo; this is especially notable on second-summer types, because > second-summer type hirundo tend to be less intensely gray than even dull > breeding adult hirundo > They have shorter, subtly different shaped bills than typical > hirundo--obviously just a supporting character, easily matched by variant > hirundo, but interesting because supposedly typical of longipennis > > Their dark bills catch the eye but as Joe noted are not that exceptional for > hirundo, even in June. In contrast, their dark legs are vastly more unusual > at this date. In my experience, dark legs are extremely rare among hirundo in > May-June, even within each of the odd-ball categories: adults that arrive > with dark bills, second-summer types, and first-summers. > > Getting back to the question at hand, yes, there have been carefully > scrutinized, documented, and published longipennis candidates from NJ, LI, > RI, and MA (I recall less clearly one from the UKin this time frame also). I > have collected (but not assembled and analyzed) the particulars on these over > the years. The place to look for the best information is not eBird or other > online sites, but rather North American Birds, the relevant state > publications, and the original documents, photos, and correspondence I've > archived (and promise some day to publish). > > The first one I remember was from Rhode Island; it was photographed and > published in North American Birds. The issues are right there on my shelf, > but I don't have time or interest to search right now. > This was earlier, I think, than one from NJ in 2003. > Another was studied and photographed by Scott Whittle and me at Moriches > Inlet in June 2009. > 2011 brought not only the LI bird we've been discussing, but another at > Muskeget Island, off Nantucket, studied by Vern Laux and photographed by > Peter Trimble. > > From an email from Dick Veit: "Factors distinguishing this [Muskeget] bird > from other terns include (aside from the blackish bill) reddish brown legs, > upperparts darker gray than local common terns, bill rather short, head more > rounded, rather "domed", underparts darkish gray (though not as dark as they > would be in May), tail feathers longer than wingtips at rest, legs seemed > slightly shorter than commons, though not as short as on arctic." > > All this typing is cramping my scope-focusing hand. I think I might just head > down to an inlet, any inlet! > > Best, > Shai > > > ________________________________________ > From: bounce-122640877-11143...@list.cornell.edu > [bounce-122640877-11143...@list.cornell.edu] on behalf of Joseph DiCostanzo > [jdic...@nyc.rr.com] > Sent: Friday, June 15, 2018 1:31 PM > To: Robert Lewis > Cc: NYSBIRDS (NYSBIRDS-L@cornell.edu) > Subject: Re: [nysbirds-l] Dark billed, dark legged Common Terns on Long Island > > I went to the ABA’s Birding News site that lists RBA’s around the country and > did a search for longipennis. For the months of May and June of this year, > most of the returns of the search seemed to refer to a dragonfly with that > scientific name. There was one bird report from the Aleutians and all other > reports came from reports on Long Island related to this discussion. > > I also searched for Siberian Tern and got nothing. > > Joe DiCostanzo > > Sent from my iPad > > On Jun 15, 2018, at 11:44 AM, Robert Lewis > <rfer...@yahoo.com<mailto:rfer...@yahoo.com>> wrote: > > Perhaps I missed it, but there seems to be an obvious question here: have > bids like this been reported from neighboring states? > > Bob Lewis > Sleepy Hollow Y > > > On Thursday, June 14, 2018, 10:49:25 AM EDT, Shaibal Mitra > <shaibal.mi...@csi.cuny.edu<mailto:shaibal.mi...@csi.cuny.edu>> wrote: > > > As I mentioned in my earlier note to the list on this subject (8 Jun 18, > copied at the very end of the present note), the jury is certainly still out > on the status of longipennis Common Terns on the east coast. Joe's highly > informed contributions are a very welcome addition to the process and > underscore several areas to focus on in resolving the matter. First, it is > clearly true that to claim an extralimital longipennis, the evidence must be > very strong and include multiple characters beyond dark bills and dark legs. > I have a lot to contribute on this front, because I have made a point of > studying non-breeding terns for more than 20 years, during which time I have > collected detailed data on large samples of carefully scored first-summers > and "second-summer types" (a category which, as Joe notes, consists of an odd > amalgam of a subset of some but not all two year-olds, older adults short of > full breeding condition, and very old, senescent adults)--not only of Common > Terns, but also of Arctic, Roseate, Least, Black, and others. > > For now I just want to make two very simple points in response to the queries > Joe raises toward the end of his note. > > First, I'd like to address Joe's skepticism about judging wing length > visually. I once wrote a long, detailed note to the ID Frontiers list > defending the critical, visual assessment of shape (i.e., the relative sizes > of morphological structures; that piece concerned warblers, or maybe willets, > or maybe I did it separately for both?). I might be able to dig it/them up, > but for now I remember demonstrating that large samples of in-hand > measurements counter-intuitively often obscure real differences between > similar species, males and females, etc. The reason is that handbooks > over-emphasize extreme data, neglecting quantitative measures of variance and > covariance, and because most observers are unprepared or unwilling to think > quantitatively. At the same time, sharp-eyed birders can unerringly > distinguish Blackpoll and Pine Warblers at a glance by shape, even though > practically all their measurements, viewed individually in huge samples, > overlap. With regard to terns, I can recognize visually how the length of an > individual's primary projection compares to the chord of its dorsum with > enough precision to distinguish Common and Arctic Terns very confidently. So > I would caution against categorically dismissing this line of evidence. > > Second, the true statuses of non-breeding seabirds remain an amazing mystery, > and the few glimpses we've had so far have been really exciting. Most > obviously, the local status of Arctic Tern has been completely re-written in > the past 20 years based precisely on attention to loafing flocks of > non-breeding terns. Furthermore, scrutiny of these flocks has yielded many > other rarities, some of them as unexpected as longipennis might seem: Elegant > Tern, Cayenne Tern, acuflavidus Sandwich Terns during June, Little Gulls > during June, etc. My point is that although the improbability of longipennis > needs to be answered with strong evidence, much stranger things have > happened. I still examine every Arctic Tern I see with the remote potential > of Antarctic Tern in mind; the non-breeders hang out together down there, so > maybe a few stick together up here, too. Ditto for examining first-summer > Least Terns for Littles and first-summer Black Terns for White-winged and > Whiskered. > > Brian Patteson recently saw a Tahiti Petrel off of Hatteras! > > Shai Mitra > Bay Shore > > > ________________________________________ > From: > bounce-122637763-11143...@list.cornell.edu<mailto:bounce-122637763-11143...@list.cornell.edu> > > [bounce-122637763-11143...@list.cornell.edu<mailto:bounce-122637763-11143...@list.cornell.edu>] > on behalf of Joseph DiCostanzo > [jdic...@nyc.rr.com<mailto:jdic...@nyc.rr.com>] > Sent: Thursday, June 14, 2018 9:08 AM > To: Robert Lewis > Cc: nysbirds-l > Subject: Re: [nysbirds-l] Dark billed, dark legged Common Terns on Long Island > > Bob, > > Molt, (and I am including change in soft part colors such as bill and leg > color under the term “molt”) is hormonally controlled. There is also > considerable variation between individuals in the timing of molt. The timing > and sequence of molt is no where as neat and fixed as many references might > lead you to believe. Having worked extensively with a banded population, > where the age of individuals is known from their banding histories, I know > how much variation there is. I have seen birds with extensive white foreheads > (or heavy speckling) and extensive carpal bars that I knew from their bands > were two years old. I have also seen two year olds that were > indistinguishable from normal adults. I have also seen that I knew were > three, or four years old (or older based on their bands) that showed speckled > foreheads and traces of carpal bars. I have seen adults in August at the > breeding colony on Great Gull Island that were already in full winter plumage > (black bill, dark legs, carpal bar). Individuals that don’t match the > expected are unusual, but they do occur. > > As for the lack of a carpal bar on these dark billed, dark legged > individuals, you are assuming that feather molt (carpal bar) and soft part > colors (legs and bill) must be in total lock-step with each other. There is > no reason they couldn’t be out of sync in some instances. As for primary > length, this is being based on photos, not actual measurements of the bird in > hand. How is the primary length being assessed? I am guessing versus tail > length. How does anyone know the tail length? > > These dark billed, dark legged Common Terns get reported every year at this > season, just at the time young Common Terns are coming back from South > America. Where are these supposed longipennis birds coming from? The race > breeds in Siberia and winters in the Indian Ocean east to Australia. If > longipennis were going to occur here on the East Coast, the fall seems a more > likely time than the spring migration. It seems far more likely that these > birds are aberrant hirundo retaining aspects of their winter/non-breeding > plumage than that there is an annual movement of Siberian based longipennis > birds through Long Island. > > Joe DiCostanzo > > Sent from my iPad > > On Jun 14, 2018, at 7:59 AM, Robert Lewis > <rfer...@yahoo.com<mailto:rfer...@yahoo.com><mailto:rfer...@yahoo.com<mailto:rfer...@yahoo.com>>> > wrote: > > Good points Joe. > > Let's go with the null hypothesis: it's an unusual Common tern (hirundo). > Apparently a Common tern in September can get gray blotches on the > underparts. During the winter they have a black bill, black legs, and a black > cap with white forehead, as first summer birds do now. If it is four - eight > months late in molt (or four months early), maybe that would explain some > features. But then there should be a prominent dark carpal bar. Instead, > there is none. Also, how to explain the very long primaries? And the fact > that the back is a bit darker gray than neighboring Commons, both adult and > immature? > > I found a number of images of longipennis on the web. Here are some screen > shots: > > Index of /lewis/birds/other_long<http://home.bway.net/lewis/birds/other_long/> > > <http://home.bway.net/lewis/birds/other_long/> > > Index of /lewis/birds/other_long > > > > > Bob Lewis > > > > On Wednesday, June 13, 2018, 9:01:37 PM EDT, Joseph DiCostanzo > <jdic...@nyc.rr.com<mailto:jdic...@nyc.rr.com><mailto:jdic...@nyc.rr.com<mailto:jdic...@nyc.rr.com>>> > wrote: > > > One thing that has to be kept in mind about dark billed and/or dark legged > Common Terns seen on Long Island in the spring is that our Common Terns > (Sterna hirundo hirundo) have dark bills and dark legs in winter (both the > young birds and adults). The possibility that these birds are just S. hirundo > hirundo retaining aspects of their winter plumage must be considered. Indeed, > given the breeding and wintering ranges of S. hirundo longipennis, S. hirundo > hirundo with retained winter characters seems a more likely possibility. > > Joe DiCostanzo > > Sent from my iPad > > -- > > Pasted here 14 Jun 2018 from note to NYSBirds 8 June 2018: > > Subject: Nickerson Beach - Possible Common Tern (longipennis) Species - > Comments and thoughts welcome > Date: Fri Jun 8 2018 1:09 am > From: Shaibal.Mitra AT csi.cuny.edu<http://csi.cuny.edu> > > > Dear Mike and all, > > > > This is an interesting bird, and well worth careful discussion. The photos > are, as is so often necessarily the case, not ideal for assessing wing > pattern and structure, and several other features. To my eye, the combination > of adult-like plumage, darkish bill, not so dark legs, and not very deeply > gray underparts is consistent with an early season variation of adult hirundo > Common Tern that we do see from time to time. > > > > The jury is certainly still out on the status of longipennis Common Terns on > the east coast, and in the past I have eBirded the ones I've seen under > regular "Common Tern"--but with lots of notation and documentation. Based on > the checklists you've linked from Jay and Michael, provisionally specifying > this form, I agree it might be best to take this approach while we work > things out. At least it would be easier to collect and access the evidence. > > > > Anyway, two of the best (and earliest in NY) candidates for longipennis were > birds at Cupsogue on 26 Jun 2011 and 24 Jun 2014. I've aggregated photos of > these at the following link: > > > > https://flic.kr/s/aHskD7WtGd > > > > As you will see, these birds were not only different in soft parts colors and > plumage from same-aged hirundo COTE, but also different in terms of structure > and molt (as explained in part in the note to this listserv from 27 Jun 2011, > copied at the end of this note). > > > > I've seen a few more also, including these two I was able to find quickly > just now: > > > > https://ebird.org/view/checkli... > > https://ebird.org/view/checkli... > > > > It seems odd that the best candidates have always been second-summer (TY) > birds, but there are two points worth emphasizing on this front. First, > subadult terns are definitely proven to be prone to wander; second, these > longipennis candidates differ very strongly in multiple ways from the range > of variation I've documented in same-aged hirundo COTE over the past 20 > years. The links in my copied email are long defunct, but I can direct those > who are interested to long series of images of TY hirundo COTE from our area. > > > > Shai Mitra > > Bay Shore > > -- > > NYSbirds-L List Info: > http://www.NortheastBirding.com/NYSbirdsWELCOME.htm > http://www.NortheastBirding.com/NYSbirdsRULES.htm > http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm > > ARCHIVES: > 1) http://firstname.lastname@example.org/maillist.html > 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L > > 3) > http://birding.aba.org/maillist/NY01 > > Please submit your observations to eBird: > http://ebird.org/content/ebird/ > > > -- > -- > NYSbirds-L List Info: > Welcome and Basics<http://www.northeastbirding.com/NYSbirdsWELCOME.htm> > Rules and Information<http://www.northeastbirding.com/NYSbirdsRULES.htm> > Subscribe, Configuration and > Leave<http://www.northeastbirding.com/NYSbirdsSubscribeConfigurationLeave.htm> > Archives: > The Mail > Archive<http://email@example.com/maillist.html> > Surfbirds<http://www.surfbirds.com/birdingmail/Group/NYSBirds-L> > ABA<http://birding.aba.org/maillist/NY01> > Please submit your observations to eBird<http://ebird.org/content/ebird/>! > -- > -- > NYSbirds-L List Info: > Welcome and Basics<http://www.northeastbirding.com/NYSbirdsWELCOME.htm> > Rules and Information<http://www.northeastbirding.com/NYSbirdsRULES.htm> > Subscribe, Configuration and > Leave<http://www.northeastbirding.com/NYSbirdsSubscribeConfigurationLeave.htm> > Archives: > The Mail > Archive<http://firstname.lastname@example.org/maillist.html> > Surfbirds<http://www.surfbirds.com/birdingmail/Group/NYSBirds-L> > ABA<http://birding.aba.org/maillist/NY01> > Please submit your observations to eBird<http://ebird.org/content/ebird/>! > -- > > -- > > NYSbirds-L List Info: > http://www.NortheastBirding.com/NYSbirdsWELCOME.htm > http://www.NortheastBirding.com/NYSbirdsRULES.htm > http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm > > ARCHIVES: > 1) http://email@example.com/maillist.html > 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L > 3) http://birding.aba.org/maillist/NY01 > > Please submit your observations to eBird: > http://ebird.org/content/ebird/ > > -- > -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME.htm http://www.NortheastBirding.com/NYSbirdsRULES.htm http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://firstname.lastname@example.org/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birding.aba.org/maillist/NY01 Please submit your observations to eBird: http://ebird.org/content/ebird/ --