I got this list from Zootierliste.de (Thanks Kowari - great site). The commonest animals according to the number of zoos which have them. Most are in Germany but there are plenty of other European zoos being added. Number means the number of institutions which have that species (out of a total of 1239 registered):
1. Europäisches Damwild - Fallow Deer 181
2. Europäischer Uhu - European eagle owl 176
3. Schnee-Eule - Snowy owl 155
4. Bennet-Känguru Bennett's/red-necked wallaby 152
5. Europäischer Weißstorch - White stork 149
6. Blauer Pfau - Common peacock 144
7. Nordamerikanischer Waschbär - raccoon 137
8. Europisches Mufflon- mouflon, Europäisches Wildschwein - wild boar, Gelbrustara - blue/gold macaw 125
9. Afrikansiche Zwergziege - African dwarf goat 120
10. Katta - ringtailed lemur 118
I think mouflon and boar are staples of German Wildparks and not as common in zoos in the UK for example. Meerkats didn't make it into the top ten though...
1. Europäisches Damwild - Fallow Deer 181
2. Europäischer Uhu - European eagle owl 176
3. Schnee-Eule - Snowy owl 155
4. Bennet-Känguru Bennett's/red-necked wallaby 152
5. Europäischer Weißstorch - White stork 149
6. Blauer Pfau - Common peacock 144
7. Nordamerikanischer Waschbär - raccoon 137
8. Europisches Mufflon- mouflon, Europäisches Wildschwein - wild boar, Gelbrustara - blue/gold macaw 125
9. Afrikansiche Zwergziege - African dwarf goat 120
10. Katta - ringtailed lemur 118
I think mouflon and boar are staples of German Wildparks and not as common in zoos in the UK for example. Meerkats didn't make it into the top ten though...