Related Program: Idaho Matters Researches Look For Cause Of Declining Trumpeter Swan Cygnets By Richard Copeland • Mar 14, 2019 Related Program: Idaho Matters ShareTweetEmail A group of swans is known as a "bevy." More than 3,000 of the water fowl have descended on the Deer Parks Wildlife Mitigation Unit near Idaho Falls. Ample feeding grounds and plenty of water in the area draws the birds to the region annually. CREDIT MICK THOMPSON / FLICKR Listen Listening... / 6:37 Trumpeter swan cygnets are dying at a startling rate, threatening the swan populations of the West. We talk with Camas Refuge Manager Brian Wehausen and wildlife biologist Andrea Kristof about what is causing these declines. Tags: trumpeter swancamas wildlife refugeShareTweetEmailView the discussion thread.