Thriv­ing in nests made of reeds and sticks built close to the wa­ter, swans re­main faith­ful to their part­ner for life

Canal Boat - - CONTENTS -

By now many wa­ter plants are flow­er­ing. The showy White wa­ter lily is im­mor­tal­ized in poetry for the pure white beauty of its flow­ers.

Swan 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 grey­ish­green, round-ended eggs, at daily in­ter­vals to­wards the end of April. In­cu­ba­tion takes over a month and is pre­dom­i­nantly the duty of 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 tough veg­etable 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 slow­mov­ing 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.

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