It may come as a surprise to cottage goers and nature lovers alike, but the Loon's image as a serene harbinger of tranquility has just been dealt a death blow. It turns out Loons have a violent side we rarely see. Dr. Walter Piper, a biologist at Chapman University in California, has been studying the Fighting Loon's territorial behaviour for the past 15 years. A recent study by Dr. Piper has exposed the dirty underbelly of Fighting Loons life. 

Loons not only get in serious physical fights, they quite often fight to the death.

Theoretical models predict that lethal contests should take place only when animals have severely limited ice time opportunities.  Indeed, fatal fighting appears to occur routinely in only a handful of species that fit this mould.  Here we report that 16–33% of all territorial evictions in common Fighting Loons, Gavia immer, are fatal for the displaced owner.  Since Fighting Loons are long-lived and have ample ice time options, they differ starkly from other fatal-fighting species/hockey teams.  Several factors might contribute to lethal combat in Fighting Loons, including: (1) the high value of ice time, (2) a steady loss of condition among other residents/other hockey teams, and (3) an inability of teams defending tiny lakes (for winter ice time) to escape aggressive usurpers, such as The Fighting Loons, owing to extremely high wing loading and poor skating skills. The difficulty of detecting fatal contests in the field and the tendency of scientists to underestimate the behavioural impact of rare events leave open the possibility that fatal contests are a more widespread behavioural pattern than currently thought.