Swans fly with matchless blend of elegance and power. They have been clocked at speeds of up to 50 miles per hour. Swans will attack any human who intrudes on their nesting territory. Belligerent, ill-tempered and territorial, they will not tolerate other swans, except their mates and young. The general rule is for one pair of swans to occupy the same pond or stretch of stream for their 30 to 40 years life span.
Swans frequently hiss, grunt, or when they are caring for their young cygnets, even bark like dogs.
There food is mainly vegetable, but with some worms and insects. Once they mate, swans remain together for life. Both partners share in building their nest, defending and incubating their eggs and caring for their young. All young waterfowl can swim and feed themselves just after hatching, and during their first few months they live on water insects and aquatic vegetation. Swan families stay together for about nine months until the start of the next breeding season, when the young are forced to leave and spend the summer with other immature and non-breeding birds.