I think I'd split that further and say maybe more North America Zoochatters have seen Walrus, as there seem to be quite a few more collections with them than in Europe. Paira Daiza has only had them since the Spring, and its a difficult year for visiting zoos obviously (I havent been to one since this virus business started). I don't know how popular Haderwijk is, but Hamburg is way up in Northern Germany and not so much on the regular Zoo visiting radar as some of the more frequent destinations I don't think.