As the four-part documentary draws in, autumn settles and the animals prepare for the cooling temperatures. For many young animals, this now means they must now go and fend for themselves.
Tonight we see Humpback whales head south to the feeding grounds on the east coast, after one of the longest migrations completed by any species and the brown bears fight for the best hunting spots before they hibernate.
Finally, an astonishing 300 million salmon, all looking to mate in the same area they hatched, return to the Alaskan waters.
Alaska, Tuesday, 9 pm – Channel 5
Image: Channel 5