I have a four month old, female pekin duck that developed this strange spot on her beak a few days ago. She lives outdoors with four other females in a large fenced area. The whole flock has constant access to water dishes and a stock tank for swimming. They are fed flock maintainer and daily veggie scraps along with whatever they may forage for. They are put in a small pen with a coop every night. Please help me figure out what this is.