Who put siberian tigers in Africa?

Well that's rare, directly referencing Heart of Darkness instead of the more famous Apocalypse Now and Spec Ops The Line.

But it does fit the setting better.

Japari park has global regions that include Africa and Asia as well as the Americas. With no monitoring or control now the friends can move freely throught all regions so a Siberian Tiger could easily be there.

"The Cuteness ! The Cuteness !"

The question would be more what they're metaphorically exploring?

Serval goes searching for Kaban-chan, who set up camp deep in the jungle, only to find she's declared herself a god over the jungle zone Friends?