The Common Loon is a migratory bird that winters in warmer regions and returns to its breeding lakes in the spring.
Given that ...
There are perfectly suitable lakes nearby that are vacant.
Why is it that ...
More than half the time, loons choose to oust the current occupants of a lake rather than just take over a new one?
Evaluate
When two loons return from their winter hideaway and are feeling the itch to breed, they have to claim a vacant lake for themselves or chase away the current occupants of a lake.
One would think it's easier to claim a vacant lake than to chase away the current occupants of a lake.
Goal
So if there are perfectly suitable, vacant lakes nearby, why are loons taking the "harder" route and trying to chase away current occupants of lakes?
Is there something especially enticing about those lakes (even though others are "suitable", are the other ones worse somehow)?
Do the loons not realize there are perfectly suitable vacant lakes nearby?
Does the conflict of chasing away the previous couple turn these two loons on and get them in the mood to breed? (I'm sure it's not that, but that's a funny correct answer)