Recent Atlantic records of Elegant Tern (Sterna elegans)

Some information on records of apparent Elegant Terns in the Atlantic, derived from various sources and originally inspired by a posting by Laurent Raty, Brussels, Belgium, on the ID Frontiers website (http://listserv.arizona.edu/archives/birdwg01.html) in Week 4, February 2001. Updated with recent records to date as far as possible - please advise of any omissions/additions required.

RANGE OF ELEGANT TERN

Referencing del Hoyo et al., 1996 (Handbook of Birds of the Word, vol. 3) Elegant Tern breeds in a restricted range on the Pacific side of N America, from S California to C Baja California and from Gulf of California to Nayarit (with 90% or more of the total known breeding population possibly in a single colony on Isla Rasa in the Gulf of California).

It regularly wanders north to N California as a post-breeding visitor from midsummer into autumn. With recent El Nino events, these northern incursions seem to have increased. It was first recorded in Oregon in 1983 but is now of annual occurrence. Irruption events took place in 1983 and 1990, with birds reaching as far north as British Columbia; in Washington, Elegant is currently described as an "irregular fall migrant on coast (usually absent but common during El Nino years)"; it is considered an exceptional visitor in Canada. No record could be found from Alaska.

The main post-breeding dispersal is to the south, with birds wintering along the Pacific coasts of America, mainly in Peru and N Chile, but a few remain in the north, as far as California, and others reach as far south as C Chile. No records could be traced from S Chile - all maps seen showed a winter range extending S at most to the latitude of Santiago de Chili (i.e., still more than 2,000 km N of the Strait of Magellan). Historically, the species is unrecorded from Argentina.

HABITAT AND MIGRATION HABITS

It seems that Elegant Tern is an almost strictly coastal species. In California, according to Joe Morlan's county lists, it is a normal visitor to all coastal counties (i.e., including the counties adjacent to the San Francisco Bay) but, among the 38 counties that are not directly adjacent to the sea, only 2 have the species on their list - Riverside and Imperial - and it is considered to be a rarity there (cf. "very rare in spring and summer at Salton Sea" which is about 140 miles NE of the Gulf of California, though connected by major waterways and water bodies, see map - National Geographic "Field Guide to Birds of North America"). It is either unrecorded or an extreme rare vagrant to any state not adjacent to the Pacific Ocean, even as close to its normal range as Arizona. Extralimital inland occurrences traced were from Arizona (3 accepted records - 4 birds) and Texas (1 accepted inland sight record), only.

It seems that Elegant is not at all a highly pelagic species. According to del Hoyo et al., (HBW 3), "migrants feed in harbours, estuaries, salt-ponds and lagoons", "non-breeders feed in lagoons and bay, avoiding rough waters". According to all maps, Elegant's winter range follows strictly the coasts. Harold Holt ("A Birder's guide to Southern California") lists the species as "hard to miss" along the coasts at the right season, but it is not even supposed to be a possibility on open ocean well offshore. Ross Silcock (http://www.rosssilcock.com/pacific.htm) provides an annotated checklist of the Birds of the Pacific Region (defined as: "the Pacific Ocean to within 200 miles of major land masses and south to 60S", "northward off North America and westward south of the Aleutian Is"; check foot of page for more detail on islands included). Within this region are a number of islands off the west coast (e.g. Guadalupe, Revillagigedo, Clipperton, Cocos Isand and the Galapagos), for which records of Elegant Tern might be expected if it had any propensity at all to travel across open ocean. The first record for any of these sites came only in 2004, from Cocos Island (Montoya & Pascal) which lies about 330 miles SW of the coast of Costa Rica, but there are apparently no records for any of the other locations on the western seaboard. There is also another record for the Pacific region, from Johnston Atoll (roughly 15 degrees W of Hawaii) - for Apr 1969, of a bird ringed in California in May 1966. This sighting seems to show that Elegant is perfectly capable of travelling long distances across open seas but is very much the exception, i.e. a vagrant.

Based on this, it seems clear that either a few tens of miles over land, or 200 miles over open water from an area where "Elegant is common", are sufficient for it to be an extremely rare and accidental species.

COASTAL RECORDS ON THE ATLANTIC SIDE OF AMERICA

In 2001 there were apparently only two accepted records on the "Atlantic side of North America":

1) 25 Jul 1889, Corpus Christi, Nueces Co., Texas: specimen, BMNH No. 91-10-20-92 (There is also a second record from Texas: 23 Dec 1985, Lake Balmorhea, Reeves Co., Texas: photographed, TPRF No. 397. But, as Balmorhea lies in the west corner of the state, close to New Mexico and roughly halfway between the Gulf of Mexico and the Gulf of California, this record can't be assigned to the "Atlantic side of N America")

2) 20 Jun 1985, Chincoteague NWR, Virginia: adult photographed

(this sighting is not mentioned in del Hoyo et al. (HBW 3), while the species is explicitly said to be accidental in TX.)

There have subsequently been a number of further records:

3) 3 Oct - 22 Nov 1999, Honeymoon Island State Recreation Area, Florida: 1 adult

4) Late fall - early winter 2000-01, Fort DeSoto, Florida: 1 adult (returning individual 3?)

5) November 2001, Texas (http://members.tripod.com/~tbrc/tern.htm)

6) 23 May 2002, Tampa, Florida: an adult paired with a Sandwich Tern was found incubating an egg on island "3-D" (see ID Frontiers website; photo and account here).

7) 6-18 August 2002, South Beach, Chatham, Massachusetts; photos are posted on the Virtual Birder site. After a thorough debate over its identity on the the ID Frontiers website the consensus is now that this individual is indeed an Elegant Tern (rather than the first North American record of Lesser Crested Tern). Initial objections to ID as Elegant centered around the pale grey rump, even though this did not show very clearly in the photos of the bird. However, examination of museum skins has shown that non-breeding individuals can show grey in the rump, and it has been suggested that this may even be typical of winter and first-year birds. Furthermore, breeding plumage specimens showed some degree of grey in the tail, earlier in the season, but none from May to July specimens which were pure white.

8) 8 Apr 2004, another debatable individual, at Loggerhead Key, Dry Tortugas (Dade), Florida; ultimately rejected and deemed a possible Sandwich x Elegant hybrid.

9) 8 Aug 2009, an orange-billed tern at Viginia Beach, Virginia, ID discussed on flickr here. The consensus on ID-Frontiers was this is a genuine Elegant, though confidently excluding hybrids remains a tricky issue.

According to Boesman [1993] (Dutch Birding 14(5):161-169), there is also one sight record on the Caribbean coast of Costa Rica - but no further info could be traced about this bird. Neither could any records be traced from the South Atlantic, but there have since been records for both South Africa and Argentina (see below).

Overall, it might be said that there has been a recent upsurge in North American east coast records, perhaps of interest regarding the latest records from the east side of the Atlantic Ocean (see below).

OCCURRENCES IN EUROPE + SOUTH ATLANTIC/INDIAN OCEAN

Currently accepted records of Elegant Terns from Europe, and other relevant records of unidentified Orange-billed Terns, are as follows:

1) 1974 - 1984 at least, Banc d'Arguin, Arcachon, Gironde, France: 1 individual, not annually; paired with Sandwich Tern - initially ID'd as Lesser Crested Tern

2) 22 Jun - 3 Jul 1982, Greencastle Point, Carlingford, Lough, Down, Northern Ireland, UK, 1 individual

2b) 1 Aug 1982, Ballymacoda, Co. Cork, Ireland, 1 individual, considered the same as (2)

3) 1984, Banc d'Arguin, Arcachon, Gironde, France; second adult in the same colony as (1), both birds paired with a Sandwich Tern; as previous bird, initially ID'd as Lesser Crested Tern

3b) 1985-1993 at least, Banc d'Arguin, Arcachon, Gironde, France: still one individual; likely to be one of the 1984 birds, but it is unclear which one - caught, color-ringed and finally ID'd as Elegant in Jun 1987

3c) 9, 10 & 28 Aug 1985, Sables d'Olonne, Vendee, France: 1 adult, considered probably one of the 2 previous birds

3d) ?? Aug 1991, St-Nazaire, Loire Atlantique, France: 1 adult, definitely the color-ringed bird from Banc d'Arguin (3b)

4) 24 - 30 Apr 1993, Llobregat Delta, Barcelona, Spain: 1 adult, photographed

5) 1995-96 at least, Ile aux Moutons, Archipel de Molene, Finistere, France: 1 individual, photographed in a Sandwich Tern colony, considered possibly same as (1) or (3)

6) 12 Jun & 15 Jul 1988, Zeebrugge, West-Vlaanderen, Belgium: 1 adult, photographed - originally rejected because of a possible hybrid origin but currently under review and could be found acceptable as Elegant (or, at least, no less acceptable than other European records)

7) 8 - 21 Jul 1999, Lady's Island, Co. Wexford, Ireland: 1 adult in winter plumage

8) 30 May - 11 Jun 2000, Langi, Esbjerg, Vestjylland, Denmark: 1 adult male in summer plumage, displaying in a Sandwich Tern colony. Pictures here.

There are a number of additional claims/sightings from France, for which record submission/acceptance is uncertain, e.g.:

9) 2 Jun 1996, Loctudy, Finistere, France

10) 6 Aug - 1 Sep 1996, Sables d'Olonne, Vendee, France

11) 13 May 2000, Banc d'Arguin, Arcachon, Gironde, France

Situation is further complicated by an additional Elegant-like bird trapped at Banc d'Arguin in 1987, for which a hybrid origin could not be discarded but that is considered very probably Elegant anyway. This bird was seen at Banc d'Arguin until 1996 at least.

Rejected record:

1 Aug 1997, Saline di Siracusa, Siracusa, Sicily, Italy: 1 adult (documentation and observation duration considered insufficient to allow a correct determination).

2001 records

12) Co Mayo, Ireland

2002 records

In 2002, there were a series of claims of Elegant Tern, including potential firsts for Britain and the Netherlands. Dates and locations are:

13) 18 May 2002 and again during period 8 July to 20 July, near Dawlish Warren, Devon, UK

14) 9 - 10 Jun 2002, The Hague, Netherlands; pictures in Surfbirds European rarity photos gallery here: 1, 2

15) 20 Jun 2002, Happisburgh, Norfolk, UK

16) 18-23 Oct 2002, Dingle, Co. Kerry, Ireland (photos on Irishbirding site)

The identity of these individuals has been the subject of intense debate and speculation. These and a number of the earlier records are discussed on the ID Frontiers and Surfbirds discussion groups. An analysis by Laurent Raty including the photos of each bird is included on the latter site on an Orange-billed Terns page.

2003 records

17) summer 2003, Orange-billed Tern - Banc d'Arguin, Arcachon, Gironde, France (see Birding World vol. 17 no. 6, p. 235); currently of unknown parentage/ID - though has been DNA sampled (cf. comments of Laurent Raty, ID Frontiers, 7/6/05, and Pierre-Andre Crochet, Zestforbirds article; rumours June 2011 that the results of DNA analysis reveal it is likely a hybrid Elegant x Sandwich Tern.)

18) 30 Jun 2003, reported from Bouin, Vendee, France

19) 14 Jul 2003, reported from ile d'Aix, Charente-Maritim, France

20) 25-31 Aug 2003, single presumed sub-adult at Corsept, Loire-Atlantique, France. A good series of pictures from 31 August available on the digimages site.

2004 records

21) 2 Apr 2004, the identity of this individual on Fuerteventura, Canary Islands, was debated

22) mid-Jun 2004, Banc d'Arguin, Arcachon, Gironde, France

23) 4 Aug 2004, Orange-billed tern, Noirmoutier Island, France, 4 August, see picture in Surfbirds European rarity photos gallery; same as 17) above.

24) 26 Sep - 5 Oct 2004, Brokdorf, Schleswig-Holstein, Germany, pictures here and in Surfbirds European rarity photos gallery here: 1, 2, 3

A detailed account and discussion of these records is found on the Club300.de pages here (includes a useful reference list).

2005 records

25) 13 Mar 2005 - Orange-billed Tern, Krom River estuary in Eastern Cape, south of Port Elizabeth, South Africa: see Feature article on Zestforbirds website. This individual is same as 17), 23) above. It was originally thought to be a hybrid offspring from a mixed pair of Sandwich Tern and Lesser Crested Tern but this conclusion was based on erroneous information. Bird looks rather large in comparison to the adjacent Sandwich Terns in the photo, and Lesser Crested Tern, at 33-40cm, is typically smaller than Sandwich Tern, 37-43cm. Also, the bird appears to have a white rump and was reported as having a pink-flushed breast. Nevertheless, beak looks on the small side and crest not prominent enough - perhaps an Elegant x Lesser Crested Tern hybrid?

26) 10 May 2005 - Stanpit Marsh/Mudeford, Christchurch harbour, Dorset, UK. Photos by Kit Day - clearly show long narrow bill, bright orange with yellowish tip, and a white rump

27) 6-10 Jun 2005 - Lagune du Dain, France; photos 1, 2, 3, in Surfbirds European rarity photos gallery

28) 18 Jul 2005 - Gormanstown, Co Meath, Republic of Ireland (13:45-14:05hrs) (2 "reliable observers")

2006 records

29) 18-23 Jan 2006 - Strandfontein Sewage Works, South Africa (first for Africa!); Hardaker photos, Gous photos, Graham photos

2007 records

30) 27 Jan 2007, Mile 4 Salt Works in Swakopmund; relocated on 11 Feb at Wlotzkas Baken photos 31) 12-14 Jul 2007 - Chipiona, Cádiz province, Spain

32) April 2007 - Buenos Aires province, Argentina, photo available

2008 records

33) 22 Feb 2008 - Buenos Aires province, Argentina, single

34) 25 Feb 2008 - Buenos Aires province, Argentina, four, with three the following day!!! This latter observation is a remarkable new development; photos in Surfbirds ID Discussion gallery here: 1, 2, 3, 4, 5; discussed here where a sighting for the Falkland Islands by Mike Bingham on 9th August 1996 is also mentioned (no photos).

[27-28 Apr 2008 - Christmas Island, Indian Ocean, single; photos here; if confirmed, another remarkable new record!]

35) Possible at Cabo de Gata, Almería, Spain, 9 August video clip

2010 records

36) By 26 April - Noirmoutier, Sébastopol polder, Vendée, France - "as usual" (info per Xavier Hindermeyer on coches-fr mailing group, per Pierre-André Crochet on WestPalBirds).

2011 records

19 August 2011, Algés, Portugal (photos via surfbirds discussion)

2012 records

37) 10-15 April (at least), Aimakapa Pond, Big Island, Hawaii (photos, HawaiiBirding yahoogroup)

38) Possible at Cabo de Gata, Almería, Spain, 11 August video clip

39) One on salt pan at Tapa El Puerto de Santa María, Bay of Cádiz nature reserve, 13 August (photos and video); a different one (yellow colour ring), same location, 14 August (photos and video); yet another, same location, 18 August (photos & video). The colour-ringed bird is presumably the same as that discussed immediately below, and for which genetic results are indicating Elegant parentage (further below).

Other Orange-billed tern records

See also the account of the orange-billed tern at Delta de l’Ebre (NE Spain) in breeding seasons of 2004 and 2005, and paired with a female Sandwich Tern. Successfully raised a single chick at l’Albufera de València (E Spain) in 2006. The bird had been ringed at Marismas del Odiel, Huelva (SW Spain) on 8 October 2002. The bird was trapped and measured, and blood samples taken, so its precise identity will surely become clear at some point!

Discussion

Considering the consistent series of records, stretching beyond the likely life expectancy of a single bird, and including some multiple sightings, the extreme improbability of these records all relating to genuine vagrant Elegant Terns is convincingly argued by Raty. He proposed three possible solutions, which are expanded here:

• We don't know enough about true range of Elegant - and it is not as confined to the Pacific coast as is supposed, i.e. it does occasionally wander overland and perhaps beyond its known southerly range limit (i.e. even as far as Cape Horn), and is not averse to pelagic voyages; the latter two issues could be accepted if coverage by birdwatchers was poor, but frequent overland travel would imply many more records on the well-watched US east coast!
• The birds all derive from "escapes"; this may seem a remarkable statement for a pelagic species, but it is the main suggestion of the authors of the species account in del Hoyo et al., (HBW 3), by M. Gochfeld & J. Burger, who state "Odd records from the Netherlands, Ireland, Spain & France (including hybridisation with T. sandvicensis) but provenance of such birds in question as species virtually unrecorded anywhere in North America away from Pacific Coast; probably attributable to escapes from shipments of exotic seabirds from wintering grounds in west South America"; these authors have published extensively on North American seabirds, so their view must carry some weight, but nothing further could be determined about any such trade!
• The birds are not Elegant Terns, but either some sort of hybrid which happens to look like Elegant, or an unknown variant of a resident species (i.e. Lesser Crested Tern, which is most similar); a possible problem with the latter is that the structure of the birds differs as well as plumage!

Further to this, it is interesting that bird 25) and subsequently 29) have occurred so far south of the typical wintering areas of Lesser Crested Tern in the Atlantic (should not be further south than north Africa!). Yet, the longitude corresponds to central Chile, which is supposed to be southern distribution limit of Elegant; if 25) is a hybrid that implies there may indeed be some Elegant Tern genes in it, whilst 29) should not really be a surprise if Elegant Terns are in the eastern Atlantic and migrating south in winter!

These latter records bring us back to the first explanation above, viz. the upsurge in European/North Atlantic records could be due to a few individuals rounding Cape Horn and getting into the wrong ocean, and this may also be consistent with their occurrence on the eastern side of the ocean, whilst the species is still very scarce on the US side. This latter explanation was my own personal favourite theory, but the new 2007-2008 records from Argentina, birds 32) and 33) (4!) call it into question again; in any case, it remains rather far-fetched and the truth is that until some of the outstanding DNA analyses are reported it would be unwise to leap to any hasty conclusions...

[Postscript - some interesting developments in June 2011 with reports that the Gironde bird may be a hybrid x sandvicensis, via DNA analysis (this thread on surfbirds - scroll down for the proper info from Pierre-André Crochet); if confirmed this would greatly strengthen the case for Elegant having occurred in Europe, but further only serve to re-emphasise the ID challenge for any individual bird.]