canalboat.co.uk Canal Boat July 2018 45
S
wan is one of our most ancient
Anglo Saxon animal names,
meaning sound or even singing.
The Mute swan is something of a
misnomer, especially since this supposedly
silent bird does communicate with vocal
noises. If you have ever approached a pair
too closely in the breeding season you will
be only too aware that these large birds – the
largest water bird in the British Isles – can
produce an intimidating loud, hoarse hiss,
often accompanied by the threatening
display of swimming with breast thrust
forward, head curved back, wings arched
and feathers ruffled. ‘Busking’ is a beautiful
sight if not rapidly targeting you. With its
majestic grace and gliding, mystical beauty,
it is not surprising that these birds are
associated with the pagan gods and
goddesses of the Celtic world.
Mute swans can be distinguished by the
black fleshy knob at the base of the beak,
larger in the male cob than the female pen,
and reaching full size as the adult swan
becomes sexually mature at between two
and four years old. Once they have found a
partner they remain faithful to their mate,
returning each spring to the same territory
to breed.
The nest is an enormous mound of reeds,
sticks and other vegetation, built close to the
water’s edge. The positioning of the nest was
watched carefully by country folk of old who
believed that the swan built it high before
floods, but low when there was no prospect
of unusual rains. It probably more closely
reflects the experience of the parent birds.
The pen lays up to seven chalky greyish-
green, round-ended eggs, at daily intervals
towards the end of April. Incubation takes
over a month and is predominantly the dutyof the pen, with the cob guarding, though he
will take his turn on the nest when she feeds
and preens. The cygnets (from the
diminutive of the old French word cygne for
swan) usually all hatch within 24 hours.
Cygnets are covered in soft, fur-like,
silvery-grey down and leave the nest for the
water after only a few days, returning to its
safety for up to a month at night.
Both parents pull up submerged
vegetation to help them feed and take the
cygnets for protective rides on their backs.
The family group remains together as the
cygnets grow and by the time they are six
months old they have brown feathers and
are able to fly – and their parents are much
less keen on feeding them.
The swan uses its long neck to feed on
underwater plants which, along with
semi-aquatic plants, make up the bulk of its
diet. Iron in the river or canal bed can stain
the feathers when they are looking for food,
giving some swans a rusty top-knot. Swans
also eat grit (and hence small lead weights,
now banned from use by anglers) to aid the
gizzard in the breakdown of its toughvegetable diet. By nowmany water plants are
flowering. The showy White water lily is
immortalized in poetry for the pure white
beauty of its flowers. The Elizabethans
believed that the powdered rhizome would
encourage chastity. The flowers, floating on
the water’s surface amongst the lily pads,
only open in sun. Its lack of submerged
leaves renders it especially vulnerable to
disturbance by boats breaking the floating
surface leaves. Much of our native
population has probably now been replaced
by cultivated escapees.
The Yellow water lily has thin, translucent,
cup-shaped underwater leaves in addition to
the thick, leathery, oval, flat ones on the
surface. Everything is attached to a rhizome
growing in the mud below still or slow-
moving water. The flowers of the Yellow
water lily are held aloft on stout upright
stems, looking more like large aquatic
buttercups than lilies, and give off an
alcoholic scent that attracts pollinating flies.
The alternative name of Brandybottle refers
to the green bottle-shaped fruit.
Enjoy the beauties of summer.WATER SIDE WILDLIFE
NOW IS THE TIME TO ENJOY BEAUTY OF SUMMER, SAYS PIP WEBSTER
SWANTHRONG
By now many water plants are
flowering. The showy White
water lily is immortalized in poetry for
the pure white beauty of its flowers.