Thank you so much for your advice - which one in your opinion is better to visit? I have visited Cologne zoo many times and like it very much so I wouldn't go there on this trip
So do mean Kronberg or Darmstadt, or Heidelberg ? Kronberg's speciality are Hoofstock, Darmstadt is a very small place, 5 hectares,so they keep very few bigger aniamls like Common Zebras and Southamerican tapir. Their speciality are reptiles with many rare species and also birds. Its also very close to Frankfurt
You can reach Heidelberg by train within an hour-its a medium size Zoo, and because its also close to Darmstadt, you can combine both Zoos at the same day, depending on how much time you spend at both places, but Heidelberg has also only 10 hectares without bigger animal houses.Normally, 3-4 houres are enough for it. The Indian grey mongoose is mostly active in the morning-depending on the wheather. If its too hot, its hiding and sleeping-if it is still alive.
They keep a bachelor group of asian elephants in a very good exhibit, Lion,Tiger,syrian brown bear with corsac foxes,binturong with small claws otters, three species of ape(gorilla, chimp,orang)and a few other species of primates-Roloway Guenon, Hanuman langur,White-belted ruffed lemur and some marmosets and tamarins.
Other Small carnivors are Fossa, Asian Golden cat,merkat,skunk,ringtailed mongosse and one very old Indian grey mongoossse in the exhibit with Rhesus Macaque. You can see also zebras, two species of antelope,Red Kangoroo and Southamerican Sealions-also some Birds, but the former famous Bird Inventory was decreased in the past years, but despite that, some very rare species are still there.
So if you are more interested in birds, small carnivours and primates, then Heidelberg is defenitely the better option for you than Opel-Zoo Kronberg. By the way-the animal welfare at Heidelberg is better than in Kronberg, and not to forget, if you wasn't yet in this famus old city, you should defenitely visit Heidleberg, one of the most beautyful old cities in germany. From the train station, take the Bus Number 32 and get out at"Zoo"-just a ten minutes ride. From Heidelberg to Darmstadt it is a 36 Minutes train ride.