Compared to the numerous Common Loons that were nearby, this bird was noticeably different. Structurally, it was smaller than the Common Loons with a smaller bill and rounder head. Common Loons have a noticeable forehead "bump" which this bird didn't have. This bird was a darker black on the back with a noticeably lighter, charcoal gray nape. It also had dark around the eye, while Common Loons have white around the eyes. Finally, the nape was a smooth charcoal gray colour and lacked the jagged lines that Common Loons have.
Fortunately, throughout the ~ 15 minute observation time, it never dived, instead just sitting in the water and preening. It was very distant, but with a fair bit of effort and a little luck I was able to get a photo!
In the above photo (taken with my phone through my scope) the loon is on the right hand side of the image. Here is a cropped version of the same photo:
It appeared to be an adult bird, mostly in winter (basic) plumage. At times I thought I could see a darker "necklace" on the bird which is just visible in the above photo. The reason why the bird has white sides in the above photos is because it was preening. When the bird was at rest, the white sides weren't visible. It wasn't an Arctic Loon!
Thanks Tyler for the great find and for calling me over!
The location is on East Lake, located in the southwest part of the Prince Edward peninsula. We viewed the bird from County Road 18, running northwest to southeast, on the southwest part of the lake. I'll be back in the morning to hopefully get better views!
For those keeping score at home, Pacific Loon is my 344th bird in Ontario this year. I ranked it as a Code-3, meaning that the only remaining Code-3 bird I need is Glossy Ibis.