Ungulates see yellow and blue, but not red. https://www.rmef.org/elk-network/what-you-see-isnt-what-that-elk-sees-eye-of-the-beholder/ https://www.rmef.org/elk

Ungulates see yellow and blue, but not red. https://www.rmef.org/elk-network/what-you-see-isnt-what-that-elk-sees-eye-of-the-beholder/ https://www.rmef.org/elk-network/what-you-see-isnt-what-that...