Light hits the eye--chemical reactions-- the bird sees --magnetic direction like a compass. They have special proteins in their eyes (called cryptochromes) that detect changes in Earth’s magnetic field. So.. 20/20 vision or compass vision? Take your pick

🧭 #BirdBrains #ScienceTwitter #ArcticTern

• Doppler Effect: When a sound source moves relative to you, the pitch changes.
• Approaching = waves bunch up = higher frequency = higher pitch.
• Receding = waves spread out = lower frequency = lower pitch.