https://www.youtube.com/watch?v=TQvbJ-spKuU
… nor singing encouraging songs to each other. Reindeer cows grunt to their calves. Calves bleat and bawl to their mothers. Males snort, hoot, bellow and rattle hoarsely when trying to attract a mate. A special inflatable laryngeal air sac gives the calls of the males extra oomph. More to sing about.