Big Breathers

The video explains how underwater mammals like whales can hold their breath longer than humans. It introduces Millie, a humpback whale, who inhales significantly more air and uses it more efficiently. Millie absorbs over 90% of the oxygen she inhales due to higher myoglobin levels in her muscles. Additionally, she conserves energy by using fewer muscles, slowing her blood flow and heartbeat, allowing her to dive for up to 20 minutes.

What adaptation allows Millie to use less oxygen while swimming?

How often can Millie breathe and how long can she dive?