Literature Reference: How can the sparrow know the ambition of the swan? — From 'Records of the Grand Historian: The Family of Chen She'.
燕: The swallow. In names, it often symbolizes good fortune and peace, signifying auspiciousness, health, and a beautiful life.
桦: The tree species, birch. "Birch" symbolizes the toughness akin to a tree, unyielding to wind and rain, metaphorically representing a robust physique conducive to good health.
Meaning: The swallow symbolizes agility and freedom, while the birch represents resilience and eternity.