This lovely bird is a Yellow Warbler. The Field Guide to Birds of the Mackenzie Delta says this one is a male, a common species throughout the region in summer.
It’s known as “Dzhii tsoo” or “Tsilch’oo” in Gwich’in language.
It can also be called “Pikka Pikani Signiq” in Inuvialuit says the book.
A fun detail from the bird guide: The call is quoted as sounding like this: “sweet, sweet, I’m so sweet“