Besides being a symbol of beauty and fidelity, swans are also known as a representative of love. It is perhaps the swans’ practice of mating for life which has inspired this connection.
The famous ballet, Swan Lake, tells the story of Princess Odette, swan by day, woman by night, who requires the faithful love of a man to break the enchantment cast over her. Siegfried is that man. The ballet has various endings, some tragic, some redeeming, but all centering around the swan and around the idea of true, abiding love.
A common romantic image of these birds show swans face-to-face, long necks arched, beaks touching. In such a pose, the birds create the shape of a heart. Their beauty and elegance easily lend them to the idealization of romance.