The wolverine is a pretty rare phenomenon in the zoo world. In Europe today there are 46 males and 43 females, distributed among 35 different zoos, and Niila, a young male shown in these pictures is one of them. In North American zoos, there are even fewer wolverines than in Europe.
I have seen wild wolverine (Gulo gulo) once in the high mountains were these animals live, but only through binoculars. It is said to be the least known of the large carnivore of the northern hemisphere, so it was kind of great to meet this individual a couple of weeks ago. Niila the wolverine is born in Helsinki Zoo in Finland, but since last summer he has been in a wilderness park in Namsskogan in Norway, were his environment is not bad for a captive animal, that is 8400 m2 of natural grounds. There are more information about these animals at The Wolverine Foundation, there is a little about the wolverines ecology on this swedish page, and there is a lot of more pictures of wolverine in my web gallery.