Cold Case

The last ice age ended about 11,500 years ago — recently enough that its effects are still plainly visible. Take drumlins, for example. Whenever I fly from Toronto to my hometown of Halifax, I see them from the airplane window: low, elongated hills, roughly teardrop shaped, the “tail” pointing in the direction in which the ice retreated, millennia ago. I probably first heard about drumlins from one of the interpretive guides at Kejimkujik National Park, but I later learned that our own house was not so far from a whopping big drumlin: Citadel Hill.

For the science writer and adventure traveller Edward Struzik, the most recent ice age did much more than just reshape the landscape. In Animal Diaspora, he explores its effects on the animals that share the planet with us, examining in detail how they responded to extreme and often sudden changes in climate — how they relocated or, in many cases, died off. While the book details a myriad of migrations and mass...