This is the time of year Trumpeter Swans get testy. Still in their family groups, but now less tolerant of other adults that encroach on their personal space, it seems they are just downright irritable. With heightened reproductive hormone levels no doubt peaking prior to the upcoming breeding season they attack anything that threatens their mates, their offspring, or whatever is in their way (geese, ducks, etc.).
On the Mississippi River in Monticello, MN where thousands of Trumpeter Swans overwinter, confrontations between adult swans are frequent in late February right before the swans depart for their breeding areas. I watched a family of swans coming in to land near another family on the river as they met with some hostile aggression in one swan-frontation lasting just a few seconds.
And that is how Trumpeter Swans feel about newcomers invading their space at this time of year. Aren’t hormones a wonderful thing? (or not…)