For female ducks, life is good! The more male ducks that are around, the better the sex life, apparently.
After breeding season, the duck penis withers away and falls off, much like an umbilical cord on a newborn human baby. The penis has done its job, and now the male duck has better things to occupy his blood flow with.
Next spring, when mating season is back in full swing, and the lady ducks are skinny dipping and ready for love, the penis grows back.
How much it grows back is dependent upon the male competition. The question I have is, how do they know what other male duck penises look like? Are there “pond comparisons”? Is there chatter among “duck mail”?
Many birds don’t grow penises (so if you believe in reincarnation, don’t ask to be a bird). However, ducks do grow penises just to deliver the sperm “goods” during mating season.