This fascinating river bird has an extraordinary
aquatic lifestyle. Inseparable from water, the Dipper is the only songbird in
Britain that feeds underwater and it has developed unique adaptations for this unusual way of life.
Dippers are usually found close to fast-flowing rivers. Photo: Andrew 2606 (Wikimedia commons)
Seeing a Dipper usually requires a special trip to its habitat,
and once you have one in view, watching it for a period of time is a highly
recommended treat.
There are about 13 subspecies of Dipper, extending across
the Palearctic from Morocco in the south to Norway in the north and eastwards
as far as the Himalayas. It is found mostly in upland regions – up to 5,000 m
in the Himalayas – but it can also occur at sea level.
Dippers like swift-flowing rivers, generally in northern and
south-western England, as well as Wales, Scotland and Ireland. Two races are
resident in Britain and Ireland: hibernicus in Ireland and western Scotland,
and gularis in eastern Scotland, Wales and England. Both are sedentary and
rarely move far from their breeding areas, except when severe weather forces
them to undertake local movements to unfrozen rivers and lakes, and sometimes
even the coast.
The British and Irish breeding population is about
7,000-20,000 pairs, at least half of which occur in Scotland. Numbers have
fluctuated since the BTO’s Waterways Bird Survey began in 1974, but on the
whole they have remained stable. The birds are sensitive to environmental
factors like acid rain, and forestry practices may have affected them in some
areas.
A third race, cinclus, occurs in Britain as a scarce
visitor. Black-bellied Dipper is one of the continental races that breeds in
the north of Scandinavia and migrates south to escape the clutches of winter.
Birds breeding in the mountains of Norway and Sweden leave for lower ground and
warmer weather in Finland, southern Sweden and western Germany. They arrive in
their winter homes in October and leave again in March.
British Dippers have a chestnut breast band. Photo: Steve Young (www.birdsonfilm.com)
Individuals of this race are usually easy to distinguish
from the British races, which have chestnut bellies. These occasional visitors
provide the opportunity to see Dippers where you wouldn’t expect them, especially
in southern and eastern England, and most occur from October onwards, often
staying until March. Ringed black-bellied birds – a Swedish bird in Fife and a
Norwegian bird on Shetland – confirm their northern origin.
One more race, aquaticus, is found in Belgium eastwards into
central Europe. It also has a chestnut belly, and while it could conceivably
occur here, in the field it is very difficult to distinguish from our races.
The dipper family is exceptional for the ability of all five
species to feed underwater by walking along a riverbed. They can also swim
underwater and are able to stay submerged by using their wings against the
current to push themselves down and by holding onto stones with their feet.
Although their feet are unwebbed, the birds can still swim across the surface.
Other adaptations that help them stay submerged include flaps over their
nostrils, well-developed wing muscles, eyes that can function underwater and
blood that stores large amounts of oxygen.
Dippers build a domed, mossy nest next to water. Photo: Steve Young (www.birdsonfilm.com)
Spending up to two thirds of the day feeding, Dippers have
well-waterproofed and dense feathers that insulate them from heat loss in the
water. To keep the feathers waterproof, Dippers use more oil than other
passerines and thus have very large preen glands. As well as walking into the
water from a rock or the shore, they will swim and submerge like a grebe, and
can even fly straight in.
Dipper is so called because of its habit of bobbing up and
down when perched, especially when excited; it has been known to make up to 60
‘dips’ per minute. It is also called White-throated Dipper to distinguish it
from other members of the family. A local name for it used to be ‘water ousel’,
‘ousel’ being an old word for Blackbird.
How to see
Look for Dippers along fast-flowing rivers and streams, but
you need to be patient as they can range over a considerable length of river. The birds perch on
exposed rocks at the edge of the water or further into the stream, so a useful
pointer to their presence is tell-tale white droppings on the rocks.
Another giveaway is their sharp, single-note call – a high,
repeated zit, usually given in flight. If you hear the call, look for a dumpy,
short-tailed bird flying low and fast over the water. Bridges over rivers are
always a good vantage point, as Dippers sometimes breed under the bridge
itself. Also listen for their sweet, warbling song, which can be heard almost
all year, as the birds use it to keep rivals out of their winter territories.
Where to watch
The following sites are just a few of the many places where
it is possible to see Dippers in their breeding habitat. However, if you
thoroughly explore any fast-flowing streams or rivers in the species’ range,
you may also be successful in tracking one down. Once found, these intriguing
birds are well worth the time spent observing them.
England
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Somerset: Willsbridge Mill (ST 665708)
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Devon: Yarner Wood (SX 786788)
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Gloucestershire: Nags Head RSPB (SO 606085)
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Staffordshire: Coombes and Churnet RSPB (SK 009534)
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Worcestershire: Wyre Forest (SO 777763)
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Lancashire: Pendle Hill (SD 805415) and Dunsop Valley,
Forest of Bowland (SD 684544)
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Cumbria: Haweswater RSPB (NY 469108)
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Durham: Upper Teesdale (NY 885286)
Scotland
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Argyll: Bridgend, Islay (NR 336624)
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Dumfries and Galloway: Wood of Cree RSPB (NX 381708)
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Aberdeenshire: Glen Tanar (NO 480965)
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Perth and Kinross: Killiecrankie (NN 906628)
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Renfrewshire: Lochwinnoch RSPB (NS 358580)
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Inverness-shire: Nethybridge (NJ 001205) and Glen Affric (NH
215241)
Wales
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Carmarthenshire: Gwenffrwd-Dinas RSPB (SN 788471)
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Ceredigion: Ynys-hir RSPB (SN 682961)
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Gwynedd: Coed Garth Gell RSPB (SH 695184) and Coedydd Aber
NNR (SH 663195)
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Glamorgan: Cwm Clydach RSPB (SN 684026)
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Pembrokeshire: Welsh Wildlife Centre (SN 186450)
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Powys: Lake Vyrnwy RSPB (SJ 016192)
Ireland
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Co Antrim: Shane’s Castle (J 120880) and Lagan Meadows NR (J
333706)
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Co Kerry: Killarney National Park (V 936846)
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Co Waterford: Lismore Bridge (X 045990)
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Co Wicklow: Glendalough (T 105965)
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