Like many hobbyist birdwatchers, the beginning of a new year means one thing for me: not
resurrecting my gym membership or briefly pretending to stop drinking beer, but starting a
fresh year list. Since I had received the surprise gift of debilitating illness during the
Christmas period, I decided to go for a leisurely wander around one of my local patches –
since, at that point, my year list consisted only of the few urban birds I’d seen longingly from
my home office window. To cut a long story short, this resulted in the curious fact that my
2024 year list proudly boasted a Long-tailed duck before I’d seen or heard a Wren.
How had I happened upon a scarce seaduck in inland Cheshire before encountering
Britain’s commonest bird? Though this species is generally a winter visitor of Britain’s
offshore habitats, this particular bird had been present at Moore Nature Reserve since
around mid-November, and remains there as of writing. Once an infrequent (or under-
recorded) visitor to the west coast of Britain, records of Long-tailed duck have been on the
rise since the mid 20th Century, as has their tendency to turn up at inland sites.
As I enjoyed watching this bird endlessly submerge then resurface like that one overactive
group chat you immediately regretted joining, I couldn’t help but imagine the journey this
individual had undergone before that moment, and thus thought it would be a good
opportunity to discuss the fascinating biology of this truly peculiar duck.
A pair of Long-tailed ducks encountered at close quarters from a beach on South Ronaldsay, Orkney. These birds were incredibly tolerant of my presence, especially considering at that point I hadn’t had access to a shower for at least four days
Often there is an interesting story woven into the name of an organism, and the Long-tailed
duck is no exception. Upon close examination, you may notice two key characteristics of the
tail: firstly, it is long. Secondly, one end of it is attached to a duck.
Well, that’s a partial truth, since there are plenty of short-tailed Long-tailed ducks: the eponymous long tail is only present in adult males. This name is probably still preferable to the historic name oldsquaw, which is still present in some (especially North American) books, but has since developed derogatory connotations and fallen from favour. The name drew comparison with women and the incessant babbling of flocks of Long-tailed ducks. Anyone that has attended a sizeable twitch will be aware that incessant babbling is not restricted to a particular gender.
The uniqueness of Long-tailed ducks is neatly reflected by their systematics: they are
monotypic (there are no accepted subspecies or races), and are the only extant species in
the genus Clangula – the name of which comes from the Latin clangere, meaning ‘to
resound’. Paired with the translation of the species epithet (hyemalis, meaning ‘of winter’)
this name refers to the distinctive wailing voice of this bird hailing the end of Autumn as they
return to their coastal wintering grounds. On the anatid (swan, goose and duck) family tree,
Long-tailed ducks sit upon the branch of true seaducks, and their genus is nestled
somewhere within the merganser and goldeneye clade (tribe Mergini). The exact placement
of some of the members of this group is slightly contentious, but the closest living relatives to Clangula may be Mergellus – the Smew – which shares the Long-tailed duck’s taste for
monochrome daywear.
The Long-tailed duck is a truly Arctic bird – breeding in the circumpolar coastal tundra and
taiga of the far north, at freezing latitudes as high as 80° N (not Fahrenheit). After somehow
mustering the enthusiasm to be intimate in literal arctic conditions, virtually the entire
population moves southwards to more hospitable conditions for the winter. Many of the
Eurasian birds spend the colder months off the coasts of Scandinavia or the Baltic Sea, but
some winter as far south as Britain. Some 14,000 wintering Long-tailed ducks spend their
non-breeding season in the United Kingdom; primarily on the coast, but a percentage of
them, intentionally or not, end up inland. A further minority evidently make the baffling
decision to spend several months on a relatively small pool near Warrington.
This species must therefore be prepared for a change of diet when transitioning from
breeding on remote Arctic pools to, for example, a rugged Scottish coast. Likewise, birds
wintering on salty lagoons will have a different menu to those retreating to the American
Great Lakes, and it's for that reason Long-tailed ducks are far from picky eaters – in fact
possessing the most varied and versatile diet of all the seaducks. Molluscs, insects,
crustaceans, fish, roe and plant matter are all at risk of becoming duck poo. I'm certain that if retail carparks were amongst their viable wintering grounds, Long-tailed ducks would be binging on discarded pastry alongside the gulls and wagtails.
Another Long-tailed duck photographed at a northwestern English inland site; this time at Elton Reservoir, Greater Manchester. Credit: Simon Warford
That being said, Long-tailed ducks favour invertebrate prey, which in turn influences their
choice in wintering habitat. It isn't uncommon to find them sharing pools with non-competing dabbling or piscivorous ducks (such as Mallards or mergansers, respectively), but will tend to avoid pools containing fish that compete for the same prey – especially when breeding. However, Long-tailed ducks are known to mingle with fellow seaducks, like eiders and scoters, in areas of plentiful food such as productive coastlines and mussel beds.
A trio of Eiders from the northeast coast of Scotland, which have perhaps the most whimsical call of all ducks, which can only be described as “ooooOOOoo”
The word duck might conjure mental images of manky Mallards mindlessly mouthing
offerings of stale Hovis, but Long-tailed ducks are amongst the many species of wildfowl that
dive for their food, and they’re virtually unmatched at it. As previously mentioned, the diet of
this species is extremely varied, so foraging tactics differ depending on available food
sources but is mostly picked off or near the bottom of the water. Most ducks propel
themselves using their feet whilst diving, but Long-tailed ducks use their wings in a manner
similar to deep-diving auks like Guillemots.
A sequence of stills demonstrating the wing-driven dive sequence of this species
Long-tailed ducks regularly dive as deep as 22 metres (approximately 13.7 Bill Oddies), and
they are so adept at this strategy that the bodies of Long-tailed ducks have been discovered
trapped in fishing equipment deployed 66 metres below the surface – making them almost
certainly the deepest divers of all wildfowl. Despite what inspirational videos on Instagram
might tell you, feats of extreme athleticism like this aren’t achieved by sheer determination
alone; Long-tailed ducks have the highest heart mass of any waterfowl, relative to body size
– even outclassing super-athletes like high-flying Bar-headed geese. Makes walking
downstairs to get another packet of crisps seem like not such a big deal now.
This species is capable of diving to depths of at least 66 metres, which is roughly equivalent to the length of two Blue whales or the wingspan of a Boeing 777 (the passengers of which would be considering asking for a refund by now)
After a winter of feeding in milder climes, the breeding population of Long-tailed ducks
begins to make the journey back up towards the Arctic. Virtually all of the birds that spent the colder months in our waters will leave and breed at much higher latitudes around the coasts of Iceland, Fennoscandia and northwestern Russia – although there are sporadic breeding records from Orkney. I can vouch for this decision as I once had a chippy so good in Kirkwall that I immediately began investigating rent prices on Rightmove.
Although this pair were likely feeding and resting on their journey northwards, it’s not implausible this pair may one day raise a brood on Orkney. Credit: Lydia Martin
Since they seem to be counterculture in virtually every other aspect of their biology, it’s only
fitting that Long-tailed ducks are unique in several aspects of their plumage. In addition to
the basic (non-breeding) and alternate (breeding) plumages utilised by other waterfowl, this
species has a third supplemental plumage, and thus their appearance is in an almost
constant transitional state between the spring and autumn. Long-tailed duck plumage also
seems to be amongst the most efficient thermal insulators of all feathers, allowing them to
maintain a suitable body temperature even whilst their bare feet are submerged in icy water
at high latitudes. If I were an Arctic seaduck, I would be very grateful that all of my duckling-
making parts are on the inside.
Despite being an animal primarily of marine habitats, this species breeds in coastal taiga and
tundra; their ducklings are raised on freshwater pools, tundra lakes, bogs and rivers.
Females display a high fidelity to breeding sites, presumably so less time is wasted seeking
out a suitable microbiome for raising a brood in an otherwise unforgiving environment. High
fidelity is also observed in males, but is likely the result of them simply following females to
their favoured nest sites as pairs reunite following a winter spent apart - another trait
convergent with auks and other seabirds.
Although monogamy is observed in around 90% of bird species, there seems to be a
tendency to evolve apparently long-term social monogamy with high mate fidelity in
disparate clades of birds that make their living out at sea, with the key difference being low
rates of divorce: it seems only sensible to reunite with the same partner and avoid the
potential costs of separating and finding a new partner (such as delayed laying) during your
limited time at a breeding colony. The open ocean is an inarguably volatile environment, so
it's a fair bet to stick with a mate that has successfully raised a brood with you before, and has genes strong enough to see them through a pelagic winter to reunite at the beginning of the following breeding season. The same can be said for longevity; many seabirds (such as tubenoses, auks and penguins) tend to be long-lived and breed relatively late into life, which seems to be a necessity if you need to spend the first few years of life acquainting yourself with an environment as vast, dynamic and dangerous as the open ocean. The oldest ringed Long-tailed duck was over 20 years old, which is comparatively ancient amongst wild ducks.
Either of these two ducks could be legally old enough to buy a pint, though they’d likely still get IDed. Credit: Lydia Martin
As previously mentioned, Long-tailed ducks are averse to water bodies containing large fish
that might compete with their largely arthropod-eating young, but may associate with other
birds that breed in remote tundra habitats. If there are avian predators nearby, such as
raptors or skuas, Long-tailed ducks may nest alongside feisty Arctic terns and Red-breasted
geese that presumably offer a certain amount of collateral protection from potential predators and plunderers. But, Long-tailed ducks are capable of engaging in their fair share of corkscrew-shaped dick moves: females have been recorded laying eggs in the nests of other female Long-tailed ducks, or even the females of other species; there are reports of
occasional brood parasitism of Scaup. There are records of a Red-breasted merganser
laying in the nest of a Long-tailed duck, so at least some semblance of karma is present in
the duck world.
A sight that would cause birding mayhem virtually anywhere else in the country: a scattered flock of Long-tailed ducks next to a main road by a major town. These birds are resting on the Peedie Sea – a remnant of marshy loch that now exists as a smallish pond in Kirkwall, Orkney. Credit: Lydia Martin
After laying and incubating her clutch of usually 6 to 9 sickeningly cute offspring, the mother
will raise her precocial young in sheltered habitats until they are ready to fledge. This period
is particularly short compared to other seaducks, as chicks are ready to move on after only
around 35 to 40 days after hatching, after which they will follow other birds to wintering
grounds and begin their prejuvenile moult – sort of like kicking your kids out after they hit
puberty at 9 years old so they can race to the other side of the country to almost immediately grow armpit hair.
A juvenile Long-tailed duck photographed in Estonia. Credit: Simon Warford
Despite a global population of several million, Long-tailed ducks are globally considered
vulnerable. Studies of some wintering populations seem to imply stability, whilst others, just
like chain wallets, have experienced a drastic decline since the 1990s. Nevertheless, they
are hunted worldwide as part of the annual wildfowl harvest, and have been since historic
(and even prehistoric) times. Aside from hunting and egg-collecting, Long-tailed ducks are at
risk from many disparate broad-scale factors that affect most marine bird populations,
including bioaccumulation of contaminants, oil spills, climate change, habitat degradation
and offshore development. The future of this bird simultaneously lies in the hands of those
performing boots-on-the-ground conservation and those influencing comprehensive changes in climate management.
To conclude, in comparison to more familiar and accessible wildfowl, there are substantial
gaps in our knowledge of its natural history – chiefly in population biology. In order to
understand what appear to be worrying downward trends in their wintering populations, there are hurdles to overcome in understanding key drivers in mortality. These shortcomings in our understanding are almost certainly influenced by the remote breeding habitats and overall offshore lifestyle of the Long-tailed duck, which I also suspect contributes to its apparent underrepresentation in the conversation of the UK’s waterfowl – and thus I hope that a peek into the natural history of this unique, extreme, exquisite and enigmatic duck is a small waddle in the direction of changing that.
Author: Sean Hennessy
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