Eagles stop cormorant removal work

Urban wildlife management is hard. This is known. 

The double-crested cormorant (the official name of the regular everyday cormorants we see around the Great Lakes) was in terminal decline a few decades ago, mainly due to toxic pesticides like DDT. Due to conservation efforts, it made a miraculous recovery, and now has a very healthy summer population in the area - perhaps too healthy.

Thing is, they are pretty unpleasant birds. Perhaps their worst habit is killing off the very trees they nest in - their guano or droppings is very acidic, as well as pungently, putridly smelly, and kills their nesting trees over time. You might have seen (and smelled!) the blighted area of trees towards the tip of Tommy Thompson Park (better known locally as the Leslie Street Spit), just offshore from downtown Toronto, where they have nested for some years now.

Having killed off that area of trees, the cormorants thought it a good idea to move just across the bay to Centre Island and infest a grove of trees there. But Centre Island is a tourist area and adjacent to the small community of people who live on the islands. Toronto naturalists and park managers tracked the move and have been trying to deter the cormorants from settling on Centre Island

However, that work is now on hold. The reason? Two bald eagles moved in to a cormorant nest on Centre Island this spring, spruced it up, tripled its size, and this has those same naturalists very excited. Because, other than another nesting pair that made an undisclosed Toronto ravine home earlier this year, these are the first bald eagles ever to settle in Canada's most populous city.

So, the cormorant removal work promptly stopped in order to give the eagles some space, and now the cormorant population on Centre Island has mushroomed from about a thousand to at least two thousand. The eagles have been seen snacking on cormorants, but that's not going to be enough to discourage them from wrecking the trees of Centre Island. 

*Sigh* What to do? Well, now that two healthy eaglets  have fully fledged from the nest, Toronto Region Conservation Area personnel believe they can now continue their work of aggressively relocating the cormorants back to Tommy Thompson Park. And I guess they will do the same thing all over again next year if the eagles return.