After a bit of deciding id say on a desert island, i mean its easier to be found on an empty island than a jungle full of trees and animals that wolud really enjoy making you have a bad time.
As long as you know how to fish and get clean water on the desert island i think you wolud be fine, on a jungle there's more dangers and not only the animals, just imagine all of the mosquitoes swarming you to get some of that sweet delicious blood, eugh...