春江水暖鸭先知
chūn​jiāng​shuǐ​nuǎn​yā​xiān​zhī

early signs

春江水暖鸭先知 (春江水暖鴨先知) chūn​jiāng​shuǐ​nuǎn​yā​xiān​zhī
early signs
The literal observation that ducks are the first to sense the warming of river water in spring, marking the arrival of the season.
professional intuition
The figurative sense that experts or those directly involved in a field are the first to detect emerging trends or shifts.

Sources
Definitions
CC-CEDICT