An ecological instrument used to measure wind direction is?

A wind vane is an ecological instrument used to measure wind direction. It's a simple device that consists of a small weather-vane mounted on a tall pole or a roof. The wind vane is shaped like a arrow, and it's free to rotate on a vertical axis. The direction that the arrow points in is the direction from which the wind is blowing. This information can be useful for a variety of purposes, including monitoring wind patterns for weather forecasting, studying air pollution, and measuring wind speeds in wind energy applications.