The animal itself
Swans pair for years and defend territory aggressively enough to break a human arm, which sits oddly with the symbolism of serenity attached to them.1 of 2 calendars · 70 searches a month
Swan
Composure over visible effort.
Which calendar assigns it, and when
Celtic calendar
2 September – 29 September
Its tree
Vine
Only the Celtic calendar assigns this one. Anyone born in these dates gets a different animal from the other system — the two agree on 4.7% of days →
What it stands for, and where that came from
Composure over visible effort — the part above the water.
Honoured in: Irish Children of Lir; Greek transformation myths; the "swan song" comes from Aesop and has no basis — swans do not sing before death.
The symbolism usually grew out of the behaviour rather than the other way round — which is the part worth keeping when the rest is set aside.