America’s Eurasian invasion
From Siberian passerines to European waders, Julian Hough looks at how and why Eurasian species are reaching the eastern USA and Canadian Maritimes.
Julian Hough investigates how Eurasian birds are reaching America.
“Wow! That would be a first record for North America – and on your first day in Cape May. Brilliant!”
On 1 July 1993 visiting compatriot Steve Duffield caught me on the stairway of our house in New Jersey and nonchalantly said: “I just had what could only have been a Whiskered Tern.” Steve’s no slouch in the birding department, but my incredulous response and the pregnant pause that followed failed to elicit further discussion. To my surprise, he continued past me up the stairs, leaving the enormity of his claim hanging in the hot summer air.
Cape May beginning
A week later, isolated reports from locals of a ‘moulting Black Tern’ and an ‘oiled Common Tern’ aroused my suspicions that a Whiskered Tern was hiding in plain sight. I ‘Avengers-assembled’ our ragtag group of Brits to stake out the South Cape May Meadows. Astonishingly, on the muggy morning of 12 July Steve’s Whiskered Tern dropped into the tern flock and catapulted a group of British ‘birding bums’ onto the front page of the New York Times.
The following day the bird performed superbly on Bunker Pond at Cape May Point State Park before flying out to sea, never to return. Remarkably, the only other two records for the Lower 48 states were also found on that same pond – in July 1998 and September 2014.
As rarity-obsessed young British birders, familiar with Atlantic systems bringing Nearctic species to the UK from the west, searching for European vagrants arriving from the east was a complete reversal for us. A vagrant is simply a bird found where it shouldn’t be, whether through migratory inexperience, a malfunctioning internal compass or some meteorological anomaly. Whatever their source, vagrants deliver an undeniable dopamine rush for birders. Richard Veit of the College of Staten Island, at the City University of New York, describes these ‘lost souls’ as the expanding fringe of a growing population.
Prevailing westerlies make transatlantic crossings from Europe difficult for small passerines, so most vagrants to eastern North America – waders, geese, ducks, herons and raptors – are stronger fliers capable of completing arduous transoceanic journeys. Let’s explore how some Eurasian species reach the USA and the surprising routes they may take.
I will focus on four broad gateways, mirrored by Howell (2014): a northern/ Newfoundland route, a mid-latitude route, a southern/Caribbean route and a western/Asian route. The Asian route, although not transatlantic in nature, is a regular source of vagrants recorded in eastern North America.
Northern gateway
A clear pattern has emerged of
European shorebirds, especially European Golden Plovers, arriving in Newfoundland and the Canadian Maritimes in early spring. Newfoundland, more than 2,600 km from Ireland and 1,300 km from Greenland, is the first landfall for displaced northern European breeders caught in easterly winds. Bruce Mactavish, a veteran Newfoundland birder, says: “Ideally we want winds flowing between Ireland and Iceland that turn east south of Iceland, or gales direct from western Ireland lasting 36 hours.” On 2-3 April 2024, such conditions brought three Whooper Swans, two Greylag, two Pink-footed and six Barnacle Geese, Common Shelduck, Eurasian Oystercatcher, five Black-tailed Godwits and 28 European Golden Plovers. Bruce adds: “European Golden Plover is the most numerous species and even in poor years we expect a few.”
This isn’t new. Flocks of 10-20 occurred on the Avalon Peninsula in April 1961, with a specimen at Cappahayden determined to be the Icelandic subspecies altifrons (Tuck,
1968). For birders farther south, these incursions are often self-contained. Outside Newfoundland, European
Golden Plover and Black-tailed Godwit remain extreme rarities – Maine
(October 2008) and Massachusetts (2019) each have just one record of the former – suggesting that these birds reorient eastwards rather than continuing south. Northern Lapwing has long been a regular Newfoundland visitor, with invasions in 1927 and 1966 (Bagg,
1967). Strong easterlies can drift birds migrating north into Britain and Ireland to Newfoundland (Tuck, 1971). Unlike other waders, Northern Lapwings sometimes wander widely, reaching as far south as Florida (1997). They’ve appeared in New England several times, including one-day wonders in Connecticut (2010, 2021). The recent bird was found late afternoon in a marsh 3 km from where I was photographing a Snowy Owl. When I turned my phone back on at dusk, messages lit it up like a pinball machine. In a race against time, a frantic 1,500-m jog along shingle, that was fighting me every step of the way, ended with sweaty success
– a Connecticut lapwing in the waning December light. It feels ironic; growing up in the UK I searched through lapwing flocks for Killdeers; now I search Killdeer flocks for lapwings!
European thrushes, notably Redwing and Fieldfare, are expected winter vagrants from December to March. In Newfoundland they often join American Robins feeding on Mountain Ash (Bruce Mactavish, pers comm). Similar congregations have carried vagrants south to Nova Scotia, New
York (1959) and Pennsylvania (2005). On 31 January 2021, at the height of the Covid pandemic, a group of Connecticut birders and I masked up and drove to Maine to see a long-staying Redwing.
Although I grew up watching nominate iliacus in Britain, I suspected the bird might be of the Icelandic form coburni. We watched it gorging on berries in the morning sun and noted the following pro-coburni characteristics; large size, oily upperparts, coalesced flank streaking, legs of a pinkish-horn colour and darkcentred undertail coverts.
Fieldfare is much rarer away from Nova Scotia and Newfoundland, with individuals in Maine (2017), Massachusetts (1986, 2013) and New York (1973), along with a historical Connecticut record (Hoyt, 1889).
Mid-latitude gateway
Strong easterly trade winds influence drift migration across both northern and mid-latitude routes, particularly during spring and autumn migrations to and from Africa. Ship-assisted vagrancy is well documented on these global shipping routes but some passerines, such as Northern Wheatears breeding in eastern Canada, are capable of completing a 14,500-km round trip across the Atlantic to wintering areas in sub-Saharan Africa (Bairlein et al 2015). Similarly, Common Swift, Common Cuckoo and Corncrake are renowned for their immense journeys.
Records of Common Swift in the eastern US show both a spring and autumn pattern. Autumn records in Bermuda suggest southbound birds entrained in easterlies, while May records in Newfoundland and the Maritimes likely involve spring overshoots. Intriguingly, individuals at Cape May in May 2024 and May 2025 may be the same bird returning north after wintering in Central or South America, a pattern that may explain the appearance of other Eurasian vagrants.
On 7 November 2017, a Corncrake was discovered foraging along a busy Long Island highway just east of New York City. Difficult to see even in
Europe, it immediately generated a big twitch. Unfortunately, a Shakespearean tragedy unfolded the next morning when, to many birders’ dismay, the bird was sadly found dead, having predictably been struck by traffic.
In November 2020, Snake Den Farm, Rhode Island, hosted a juvenile Common Cuckoo – only the third record for the Lower 48! We arrived to find it showing down to feet for its assembled admirers. Unlike many Nearctic Yellow-billed and Black-billed Cuckoos that reach European shores this individual appeared healthy and seemed destined to avoid the word ‘moribund’ next to its entry in the annual rarity report. Coincidentally, at the time of writing, the fourth and fifth records of Common Cuckoo have fallen quickly – a well-observed juvenile on eastern Long Island, New York, in October 2025 and a one-day wonder in
New Hampshire a month later.
Common Kestrel is rare with single records from New Jersey (September 1972) and Massachusetts (2002), and two from Nova Scotia (1987-88 and 201415). No clear seasonal patterns exist but Howell (2014) mentions southerly records from Florida (2003), the Caribbean, Trinidad and northern South America suggesting ship-assistance may also be involved in some cases.
One of the most surprising vagrants I’ve seen in eastern North America was a Red-footed Falcon on Martha’s Vineyard, Massachusetts, in August
2004. Four records from Iceland (all post 1980) hinted at its vagrancy potential west of its normal range. Perhaps it was carried west in spring by a tropical depression from Africa and made initial landfall in the Caribbean or Lesser Antilles before moving north? An equally plausible theory was that it hitched a ride on a ship (Hough 2004). It remains the sole record for the Americas.
Another long-distance migrant, Eurasian Hobby, is also exceptionally rare. The only two east-coast May records are from Massachusetts. My friend Ian Davies found the first from his dining room window in Plymouth (2011), while the second landed on a survey ship 160 km off Cape Cod (2019).
Western Marsh Harrier is an extremely rare vagrant in the eastern USA. Records from the West Indies imply that it can arrive by a southerly route, but an intriguing story involves an individual found in northern Maine in August 2022. It was refound briefly on 8 November in northern New Jersey, 650 km to the south-west. The United States Department of Agriculture (USDA) reported in its newsletter that: “On 22 November a United Airlines jet on final
approach into nearby Newark Airport reported a bird strike at 3,000 ft [900 m]”. There was no aircraft damage but the bird’s remains on the fuselage were sent for analysis to the Smithsonian Feather Lab which confirmed the ID as Western Marsh Harrier – almost certainly the same bird. A tragic end for one of nature’s risk-takers.
In Delaware on 11 August 1997, respected birder Michael O’Brien was leading a workshop and observed an unfamiliar, low-circling raptor. He identified it as a European Honey Buzzard and documented the sighting with excellent notes that even allowed it to be aged and sexed as an adult male. Although not yet accepted by the Delaware committee, it would represent the only record of this species in the
New World.
Caribbean/southern gateway
European vagrants frequently reach the Lesser Antilles – first landfall for Afrotropical migrants crossing the Atlantic. In addition to easterly trade winds, August to September is hurricane season, with strong systems perhaps responsible for carrying species such as Collared Pratincole, Squacco Heron, European Bee-eater, Hen and Western Marsh Harriers, and Common and Alpine Swifts to islands in the West Indies chain, especially Barbados. These birds may then move north to North America, perhaps explaining the east-coast records of Whiskered and White-winged Terns and Western Reef Heron. The August records of reef heron in Massachusetts (1983), Newfoundland (2005), Nova Scotia and New Hampshire (2006 – possibly the same bird) and New York (2007) may also fit the mid-latitude route hypothesis regarding origin.
Asian gateway
Due to its close proximity Western Europe seems to be the expected source for eastern US vagrants, but the situation is more complicated than that. Many shorebirds that have occurred on the eastern seaboard, such as Marsh, Terek and Broad-billed Sandpipers and Spotted Redshank, likely originated from Asia before dispersing east across the continent.
For example, a Common Redshank seen in Michigan in July 2022 and later refound 1,200 km east on Monomoy Island, Massachusetts, was clearly of Asian origin (suggestive of the subspecies ussuriensis), with dark upperparts, heavily streaked underparts and a long bill. The scarcity of north-eastern records of juvenile Curlew Sandpiper and Little Stint also hint at birds that arrive from the west rather than Europe. Adults of both species that show up in late summer may involve birds that arrived as juveniles in previous autumns and then mix with northward-bound Semipalmated Sandpipers.
In October 2004, I found what at the time was classified as Connecticut’s first Snowy Plover on my patch in New Haven. At that time I noted features more consistent with the Old-World forms, known as Kentish Plover – taxa that were unrecorded in the New World. After their 2009 split (Küpper et al), the Connecticut bird was reassessed as Kentish Plover (Hough and Bevier, 2025) – the first record for the New World. The only other record is from Shemya Island, Alaska (Pohlen et al, 2025). The Connecticut bird might have originated from north-east Asia rather than from Europe – a similar origin for other vagrant shorebirds.
Wood Sandpiper is very rare in the east, and while the few records of juveniles might fit drift migrants, a handful of spring adults might represent birds moving north having crossed the Atlantic the previous autumn. The only Nearctic Wood Sandpiper I have observed was in Rhode Island (October 2012). It was found by a local birder when he stopped to make a random ‘pee break’ and is a perfect example of how rarity finding requires fieldcraft and at other times just a full bladder.
One good barometer of a species’ vagrancy source and potential is to examine records from Iceland and those of the eastern Caribbean and compare them with records from the eastern seaboard of North America. These patterns clearly show which route some vagrants take. As an example of vagrant Eurasian passerines, Howell (2014) uses Brambling records to show the linear west-to-east decrease in state records. This pattern of vagrancy, spreading from Asia east across the North American continent (rather than from mainland Europe) is reinforced by the paucity of east-coast records of the abundant and migratory Chaffinch. Records of Arctic Warbler in Bermuda (February 2014) and New York City (September 2025) suggest a reverse migration from Alaskan breeding grounds rather than transatlantic vagrancy from the east. The Bermuda individual likely arrived the previous autumn and overwintered.
I have only scratched the surface of this topic and point you towards the more comprehensive and insightful work in Howell et al (2014) for more in-depth discussion. Vagrants continue to intrigue and challenge assumptions. Consider the Pallid Harrier in Barbados (2014), Red-flanked Bluetail wintering in a suburban New Jersey garden (202324) and possibly the same returning bird in Virginia (January 2026), Greater Sand Plover in Newfoundland (2025) and, perhaps most intriguingly of all, photos I have of an Apus swift found exhausted in a street in eastern Canada in 2007 that suggest it may be the New World’s first Pallid Swift – but that’s another long story for another day. If only birds could talk! ■