canalboat.co.uk Canal Boat November 2017 67
WATERSIDE WILDLIFE
There’s more to the average duck than
meets the eye, as Pip Webster revealsDucking and diving
T
he number of ducks to
be seen on our
waterways increases
dramatically with the arrival of
winter migrants.
They are divided by their
feeding behaviour into either
‘dabbling’ or ‘diving’ ducks,
and modern molecular
analysis has shown that these
sub-divisions are quite
distinct, convergent evolution
producing the ‘duck’
appearance in two different
groups of waterfowl.
Mallards, our most common
British duck, are dabbling
ducks – shallow water birds
that feed primarily along the
surface or by tipping headfirst
into the water. The inside of
their beaks have tiny rows of
plates (lamellae) through
which they can filter the
water, trapping food – you
have probably noticed the
roughness of a mallard’s beak
if you have been nipped by
one when it takes bread from
your fingers.
Dabbling ducks are typically
omnivorous, eating plant
matter, insects and worms.
They dive infrequently – often
just to avoid predators – and
are equally happy grazing on
male’s call, used in flight to
maintain the cohesion of the
flock.
The wigeon is primarily a
winter visitor that gathers in
large numbers, particularly on
wet grasslands and reservoirs
with gently sloping edges
where they can easily get out
to graze on the grassy banks.
These medium-sized ducks
have round heads and a short
bill and can be seen dabbling
in close-knit groups.
Males are grey with a pink
breast, orange head, yellow
forehead and obvious white
wing patches which show
when they fly. The females
have the duck habit of looking
like female mallards, though
their plumage is more rusty
brown and tail more pointed.
The real showman of the
dabbling duck world is the
mandarin drake. Suitably
exotic looking for a bird of
south-east Asian origin,escapees from wildfowl
collections were joined by
mandarin ducks introduced
into southern Britain in the
early 20th century.
They were thought to be
endangered in their
homelands until a large
population was subsequently
discovered in mainland China,
but fortunately it is a rare
example of a non-native
species which appears to have
no negative effects on native
ecosystems. Mandarins have
now spread throughout Britain
and often perch in trees near
lakes, rivers and canals.
Drakes have distinctive bushy
orange ‘whiskers’ and a
triangular orange ‘sale’ on the
back; females white eye
patches In traditional Chinese
culture mandarin ducks have
become a symbol of conjugal
affection and fidelity.
Enjoy watching the ducks
busy in the river near you.the land. They tend to
have flat, broad beaks and
float high on the water
with their tail held clear
while swimming. When
taking flight they spring into
the air rather than pattering
across the water.
In contrast, diving ducks
dive deeply and swim
underwater to feed on aquatic
vegetation, insects and
occasionally small fish. They
usually have smaller tails and
wings but larger feet than
dabbling ducks to aid their
diving. Their legs are set
further back on their body,
making them uncertain
walkers on the land. They run
across the water to take off, so
tend to be found on large,
open bodies of water such as
reservoirs, lakes and estuaries.
The distinctive black and
white (male) tufted duck with
its black top-knot tuft dives up
to 15 metres to catch
molluscs.
Dabbling (or ‘puddle’) ducks
are much more common than
diving ducks in Britain,
especially along canals. Our
smallest native duck, the Teal,
is particularly fond of shallow
slow-moving water where
there is good cover – canals
can be too deep for this
attractive little bird with a
broad green (‘teal’) band on
the chestnut-coloured head of
the drake.
As in all ducks, the female is
much drabber and more
difficult to distinguish until
you have your eye in for size
and ‘jizz’ (behaviour). The
name ‘teal’ dates back to at
least the 13th Century and is
probably imitative of theMigrant ducks move inCB