Pacific Loons breed sparsely in Ontario along the Hudson Bay coast in northern Ontario. They are a prized find in southern Ontario.

Pacific Loons in juvenal plumage have distinctly scaly backs in rows. They have a faint narrow chinstrap forming a dark line across the throat at the top of the neck. They show a clearcut divide between the straight or smoothly curved vertical dark border separating the white foreneck and gray hindneck. Pacific Loons often show a more cobra-like puffy head than Common Loons. 1 December 2005.

Pacific Loon in juvenal plumage showing scaly back, chinstrap and clearcut divide between white foreneck and gray hindneck. Ajax, 1 December 2005.