Wax covers some aquatic birds' feathers and some plants' leaf surfaces. Because of waxes' hydrophobic nature, they prevent water from sticking on the surface (Figure). Long fatty acid chains esterified to long-chain alcohols comprise waxes.

The photo shows leaves on a plant; the leaves appear thick, shiny, and waxy.
Lipids comprise waxy coverings on some leaves. (credit: Roger Griffith)