They’ve been happily living in British Columbia all along.
If I’m recalling correctly, there was one statistic in the 1970s along the lines that there were more bald eagles living in Vancouver’s Stanley Park than in the lower 48 US states.
No effort at all to see their nests from the outdoor theatre at Malkin Bowl.
https://stanleyparkecology.ca/2018/02/28/eagles-nesting-stanley-park/
Here’s the review from Cinemablend.
Not sure I agree that season 4 was the best. I’m in the camp that felt the pacing was off. But then I really liked seasons 1 & 3, and ran hot and cold on season 2, which pretty much makes me an outlier among Discovery fans.