Will the black swan move south in winter?

Black swans will move south in winter for better foraging.

Swan's body is covered with very fine feathers, which has strong warmth and water resistance, so swan, like other geese and ducks, is not afraid of how cold it is enough to spend the cold winter in the north. The main food of swans is algae and small aquatic animals. Once the water surface freezes in winter, they can't put their long necks down to feed, so they have to migrate south to find unfrozen waters for wintering. The fundamental reason of animal migration is natural selection. Migratory species can leave more offspring than non-migratory species. Scientists have found that among the external factors that lead to migration, the periodic change of sunshine is the most important factor, even in winter; Increasing sunshine time can also induce the migration behavior of many animals in non-tropical areas. Now there is evidence that hormone changes in many animals dominate their migration behavior, such as various birds. Once animals are in conditions suitable for migration, they will start to migrate as long as they have some environmental factors that induce migration. Black fish and locusts wait for good weather conditions to start, and fish wait for the right tide; The migration of aphids must wait until the temperature reaches a certain value.