What kind of animal inspired Wang Xizhi's calligraphy?

Wang Xizhi got the inspiration of calligraphy from geese.

Sitting in the pavilion, Wang Xizhi watched the white geese frolicking in the lake, and the graceful posture of the slender neck of the geese was inspired by calligraphy and brushwork. The rocks are composed of repeated and simple straight lines and curves, and then painted with colors such as azurite, stone green and khaki, imitating the green landscape style of the Tang Dynasty. Not deliberately pursuing Gu Zhuo's interest, but full of nostalgia.