What is the significance of birds in ancient poetry?

There are many explanations. I think Yuanyang symbolizes harmony and intimacy between husband and wife, Jade Bird symbolizes happiness and good news, Dapeng represents lofty aspirations and bright future, while Phoenix and Peacock often symbolize happiness and auspiciousness ... In addition, birds and their classes also reveal certain images in the specific environment and artistic conception in ancient poetry, such as "staying by the pool" and "shocking birds in the moon", which reveal tranquility and serenity when describing the quiet situation at night. The words "bird" and "sparrow" appear in ancient poetry, which symbolizes humble ambition and steals peace.