Sorry to contradict, but seperating Europe in the way mentioned above is quite not fitting; while large countries like France consist of more than just the Mediterranean coast (France does have alpine & lowland areas, and f.e. Slovakia & CZ are not just "alpine", just like other "flat" countries mentioned do share some mountains), Portugal has no Mediterranean area and other European countries like Croatia are somehow neglected by Your suggestion.
May I suggest a rather common version:
Northern Europe: Scandinavia-the states mentioned above, including Iceland (although I don't know whether Iceland has any zoos at all...)
Middle Europe: Benelux, Germany, Austria, Switzerland
Western Europe: France, Spain, Portugal, Canary Islands
Southern Europe: Italy, Greece, Croatia, Bulgaria...
Eastern Europe: Czech Repuplic, Slovacia, Poland, Hungary, Estonia...
Interactive Map of Europe