The Kangaroo (S04E03)

Mark Evans and Joy Reidenberg travel to Australia to examine the country's emblematic animal, revealing unexpected discoveries about kangaroo reproductive anatomy—males possess backward-facing genitalia, while females have three vaginas. Meanwhile, Simon Watt explores the Blue Mountains alongside Charles Darwin's great-great-grandson, seeking out unique wildlife, including a bird known for adorning its nest with various blue items and a primitive egg-laying mammal reminiscent of reptiles.