How did the ancients predict the weather according to the biological changes outside?

At first, people did not grasp the seasonal change of climate according to the observation of astronomical phenomena, but according to the information revealed by the responses of natural living things and abiotic things to climate change (such as the rise and fall of vegetation, the presence or absence of birds and animals, the freezing of frost, etc.). ), as the basis of engaging in agricultural activities, this is phenology. In China, some ethnic minorities who have more or less maintained primitive agricultural elements have always maintained the habit of taking phenology as the main indicator of agricultural time, and some even formed a phenological timing system-phenological calendar. The Central Plains of China should have experienced such a stage in ancient times. According to legend, officials in Shao Hao in the Yellow Emperor era were all named after birds: Xuanniao Division (vernal equinox and autumnal equinox), Zhao Bosi Division (summer solstice and winter solstice), Qingniao Division (beginning of spring, Changxia) and Danniao Division (beginning of autumn, beginning of winter). Xuanniao is a swallow, which usually comes and goes at the vernal equinox. Zhao Bo is a shrike, which usually comes and goes in summer. Bluebirds are pigeons and geese, which usually start singing in spring and stop in long summer. Danniao is a pheasant, which usually comes and goes in autumn and starts in winter. Named after the officials in charge of separation, arrival, opening and customs clearance, it shows that in ancient times, the arrival and departure of migratory birds did have the experience of symbolizing the seasons.