Razors and Blades Model

Biological Parallel

Male bowerbirds invest heavily in constructing elaborate bowers (the "razor")—structures requiring initial effort but minimal upkeep. However, they must continuously provision the bower with fresh decorations (the "blades")—colorful flowers, berries, and shells that decay and require constant replacement. Females assess males based on bower maintenance, making the recurring decoration cost the true signal of male quality, while the initial structure is merely the platform that enables ongoing signaling.