The bald eagle is the national symbols of the United States. Bald eagles are common everywhere in North America and Americans chose the magnificent bald eagle to symbolize their nation, just as Canadians chose the industrious beaver.
The bald eagle in the picture is the one named Mikisi who lives in a separate cage at the entrance of the Toronto Zoo. This bald eagle was brought into the zoo injured when it was very young, and it has lived there ever since.
I did try to take pictures of the other bald eagles living further back in the Canadian Domain exhibit of the zoo, but they live in a very large cage — more like an aviary — that visitors of the zoo are not supposed to approach to close, and I could not get anything that did not have cage wires in front of the eagles.
Bald Eagles are fortunately doing well in the wild, thanks to the protection measures they enjoy. In particular the government of the Unites States takes protecting the bird that is their national symbol very seriously.
Like all birds of prey they are vulnerable to the usual threats that endanger animals at the top of the food chain, such as industrial pesticides accumulating as we go up the food chain, and habitat destruction.
A much better picture of Mikisi the bald eagle.
American Bald Eagle Information
Bald Eagle on Wikipedia.
And just to show how seriously Americans take protecting their national symbol:
The Bald Eagle and Golden Protection Act on Wikipedia.