Researchers discover behavioral phenomenon in swans - study
By observing agression, rest and maintenance such as preening and cleaning feathers, the researchers found that the energy expended by aggressive behavior reduced the swans' resting time.
An adult mute swan (Cygnus olor) in a pond near Vrhnika, Slovenia(photo credit: Yerpo/CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)/VIA WIKIMEDIA COMMONS)ByJERUSALEM POST STAFF
