The unusual behaviour of these birds has also led to a change in the appearance of Ecuadorian squirrels, whose tails are, on average, 65% shorter than in other Squirrel species. These squirrels also sit on their tails when at rest unlike other squirrels whose tails stick out behind them when they are sitting still eating a nut. It’s also believed the Ecuadorian Ground Squirrel may have evolved from particular families of Ecuadorian Squirrels who lived close to hawk’s nests and who were attacked more than other squirrels.

These squirrels confused early explorers who would see a squirrel that had been attacked by an Ecuadorian Squirrel Hawk and conclude they had found the squirrel equivalent of the Manx Cat.  Once the explanation was discovered, some Victorian explorers even began to explore the Isle of Man, looking for a Manx Cat Hawk, a potential distant relation of the Ecuadorian Squirrel Hawk, but no evidence of this bird was ever found.

This is an extract from the book Animals Evolution Avoided