Complaints are common. Cormorants kill trees. They eat too many fish. Their colonies stink. 

Warren Hoselton has had enough. After three years of watching his beloved trees around his Ontario home be decimated by cormorant poop, he wants action. The birds have to go. 

But not everyone has a hate-on for cormorants. Avian ecologists say it's not fair to fault birds for doing what nature designed them to do. 

The ones living in a park on the edges of Canada’s largest city, reached 20,000 this year, angering locals worried about their impact. In Toronto, they’re trying to relocate them. Elsewhere, hunters shoot them.  

All across North America cormorants make enemies because of the mess  they leave behind.

Storylines is part of the CBC Audio Doc Unit