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 <[email protected]> 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 > <[email protected]> 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: [email protected] > [[email protected]] on behalf of Joseph DiCostanzo > [[email protected]] > 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 > <[email protected]<mailto:[email protected]>> 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 > <[email protected]<mailto:[email protected]>> 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 > > > 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://www.mail-archive.com/[email protected]/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 > Rules and Information > Subscribe, Configuration and Leave > Archives: > The Mail Archive > Surfbirds > ABA > Please submit your observations to 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://www.mail-archive.com/[email protected]/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/ --
