Dr. Piper likes researching why loons barge into other loons' territories, events called territorial intrusions. A loon that visits or tries to take over another loon's territory is called an intruder, so now you know the vocabulary. Dr. Piper and co-investigators Keren Tischler and Margaret Klich studied territory acquisitions of loons in northern Wisconsin. Hagge Mated pairs defend territories, and you might be surprised to learn that BOTH males and females can be kicked off their territories by intruders. Quite often they find new territories with new mates.
Intruders gain breeding status by displacing one member of a breeding pair.
You might say that breeding status is what loons live for. Like your own voice, the yodel call of a male loon is one of a kind. A male's territorial yodel discourages visits by intruders. However, preliminary data indicate that a male's yodel might change substantially if that loon is chased off its territory by another male loon and forced to move elsewhere. Dr. Piper sent us three loon yodels.