https://www.wildernessyukon.com/celeb... swans: trumpeters. At up to four-and-a-half feet tall, 35 pounds, with 8-foot wingspans, They have a gland near their rump that they squeeze with their bill to release oil, which they spread on their feathers; this oil keeps feathers waterproof, flexible, and inhibits growth of fungi and bacteria. https://explorenorthblog.com/the-swan...