Achromatic: Vision

Many animals use achromatic vision for critical survival tasks even when they possess color vision. This paper could analyze "signal efficacy"—for instance, why birds like crows sometimes ignore bright red fruit and instead use achromatic contrast to find dark blueberries against varied backgrounds. It would argue that achromatic vision is more reliable in low-light or high-clutter environments where color information becomes "noisy".

1. The "Ghost" Signals: Interdependence of Chromatic and Achromatic Pathways achromatic vision

2. Evolutionary Strategy: Why Some Animals Prioritize Gray Over Color Many animals use achromatic vision for critical survival