Pi describes the case of a black leopard who escaped the Zurich Zoo and lived in the area undetected (with the whole city on alert) for ten weeks. Pi wonders that such a huge predator could live secretly for so long, and uses this to prove that animals are always just trying to fit into whatever environment they find themselves in. Pi thinks that cities are full of big wild animals, and references someone trying to find an animal in the Mexican jungle.
These anecdotes seem like simple digressions at first, but we will later see that Pi has been using them to buttress his argument the whole time – he will refer to the Zurich panther when trying to convince his interviewers of his story’s believability. Later it will become clear that Pi’s story really does result in a large animal living in the Mexican jungle.