These bears are first in line for a nutritious catch.

這些熊排在第一位，等待一場富含營養的狩獵。

Triggered by hormonal changes, the grizzly bears now enter a phase of hyperphagia.

受到荷爾蒙變化的驅使，灰熊們如今進入了食慾過盛的階段。

This allows them to eat constantly for up to 20 hours a day, without ever feeling full.

這使得牠們能夠在一天中不斷地進食高達 20 小時都不會覺得飽。

They can consume up to 100,000 calories in a single day.

牠們一天內可以攝取高達 10 萬卡路里的熱量。

And given the abundance of salmon, they can afford to be picky.

而且由於鮭魚量十分充沛，牠們甚至可以很挑食。

Just like the bears in the tropics, they seek out the highest form of energy.

就像其他在熱帶的熊，牠們會找尋最高的能量形式。

Selecting only the fat rich eggs, the skin and brain of the fish.

只吃高脂肪的卵、魚皮和魚的腦。

In open water, it's not always easy.

在開放式的水域，並非一直如此簡單。

But as the salmon move further upstream, the grizzlies are here too.

但隨著鮭魚逐漸往上游移動，灰熊們也在這等著。

Where the river narrows it will be easier to land a catch.

河流變狹窄的地方，更容易抓到魚。