How might large and complex nasal cavities conserve water during exhalation?

The nasal cavity is lined with mucous membranes that are rich in blood vessels and sinuses, which help to humidify and warm the air moving into the lungs. This process helps to prevent water loss through evaporation from the lungs, especially in dry climates or during heavy exertion.

The large and complex nasal cavities found in some mammals, such as camels, may help to further conserve water during exhalation by increasing the contact area between the air and the mucous membranes. This allows for more efficient humidification of the inspired air and reduces the amount of water vapor lost through evaporation during exhalation.

Additionally, the tortuous structure of the nasal cavity in these animals creates turbulence in the airflow, which helps to slow down the exhaled air and promotes further water absorption. This mechanism is particularly important in arid environments where water conservation is crucial for survival.