About 5,000 animals from around the world live at the zoo, representing about 500 species, including apes, monkeys, bears, big cats, elephants, as well as birds, reptiles, and fish.

Major Alastair Hunt was responsible for trying several Nazi war criminals, notably Gestapo and SS Commander Standartenfuhrer Erich Isselhorst and SS-Hauptsturmführer Fritz Hartjenstein.

A new large-cat building was constructed in 1970 to replace the old lion house and moated lion enclosure, followed by a renovated aquarium in 1974, an ape pavilion in 1978, a renovated primate house in 1985 and, in 1993, an aviary for South American birds, which was added to the bird building constructed in 1960.

[1] The gorilla enclosure was updated and expanded to 525 square metres (5,650 sq ft) in 2006, coinciding with the 125th anniversary of the opening of the zoo.

[6] The zoo's rocky and hilly terrain, as well as the city's humid and rainy climate, has led it to specialize in animals native to alpine tundra, temperate deciduous forests, and tropical rainforests.