i read a good theory as to why (SPOILER)polar bears ended up in tunisia and I'm 99% sure it is correct. it goes something like this:

(SPOILER)ok so ben turned the wheel, transported the island and was teleported to tunisia in doing so.

the cave place with the wheel is very cold and ben had trouble pushing it

whoever turns the wheel is transported and is unable to return as ben said

the polar bears are clearly property of the dharma initiative

put all those together and you can come to the conclusion that the dharma initiative brought polar bears to the island because theyre strong and can stand cold, so they could get the bears to push the wheel. that way the bear would be transported and they wouldnt have to sacrifice a member of their team from the island.

since there are bear remains in tunisia it makes sense that their plan worked and the island has been moved more than once