How do ducks, geese and other waterfowl float on water?
“Ducks are well adapted to allow them to stay afloat without using too much energy. Ducks’ bones are hollow for buoyancy, and a thick layer of feathers that interlock to trap air increases this effect. This air cushion also provides insulation in cold water to conserve body heat. Ducks’ webbed feet further decrease the amount of energy spent in swimming. In addition, ducks have a special oil-producing gland beneath their tails, the uropygial gland. Preening spreads this oil over a duck’s feathers, rendering them waterproof. This suggests that a duck that had the misfortune to swim through a floating patch of degreaser would lose its waterproofing oil and eventually drown.
