St. Andrews Bay, South Georgia.
Penguins have a single annual molt, usually after breeding, king penguins molt before breeding. All feathers are pushed out by the new forming papillae and they simultaneously molt. During molting penguins must stay on land because they lose their waterproofing capabilities; thus during this period, 2–4 weeks, they have to fast. Molting is a high energy process for which the penguins prepare themselves with a long foraging period at sea, increasing their body weight by 50–70%. This additional weight is lost during the molting fast.
