Already in the 1920s the City Council of Duisburg had plans for a zoological park with especially indigenous species. But only years later the first serious steps were taken to establish such a zoo, when the director of the City's parks and garden department, Josef Liebig, took the initiative to found the 'Duisburg-Hamborner Tierparkverein' on 11 August 1933. At the time the two adjacent municipalities of Duisburg and Hamborn were in the process of merging which was completed in 1935. The Zoological Association with soon 1.500 members, was self-sustainable right from the beginning. To advertise the idea of a city zoo an animal exhibition was organised in the building of Duisburg's Society in the city centre, which was opened by the Mayor Ernst-Heinrich Kelter in November 1933. This successful exhibition generated the necessary funds to buy 6 hectares of land at the foot of the Kaiserberg, northeast of the city.
The first buildings were erected together with volunteers and forced labourers. They used timber which came from the logging just next door where the new highway was constructed. Later this became a bit of a problem when the Zoo wanted to expand. On 12 May 1934 Duisburg Zoo opened its gate for the first time. On barely 1 ha visitors could see inter alia monkeys, bears, deer, lions, birds of prey, as well as the first aquarium. Already during the first year they were able to develop another 4 ha of the area, and improve the enclosures for the monkeys, lions and bears. The Zoo received 300.000 visitors in its first year.
In 1935 one by one the wooden buildings were replaced by brick ones, and the first big attraction was established – the House of thousand fishes. More improvements were made and the first successful breeding results were welcomed (e.g. monkeys, lions, bears, and leopards) with the rare black-necked swan (Cygnus melanocoryphus) as one of the highlights. For promotional purposes they had two Asian elephants on loan, but without the proper facilities these could not stay. In 1938 the Zoo had grown until 8 ha, and further expansion was limited by the highway on the eastern side and the Ehrenfriedhof (cemetery) on the other side.
Unfortunately, this prosperous start was abruptly ended by the second World War. First the government ordered all predators, such as the big cats and bears, to be killed and all fish eaters to be released. To feed the animals that were left household waste was collected. Though the circumstances were terrible, they managed to build a new raccoon enclosure. Then at the end of the war the Zoo was hit by numerous firebombs and shell bombs, with a devastating result. In 1945 almost all buildings and enclosures were found destroyed, and just an emu, three flamingos, a donkey and some goats and sheep were still alive. They had to start all over again. And they did.
The years after the war were difficult, not only because of budgetary issues, but also due to shortages in building materials. Therefore they had to order thick window panes in other countries, because these could not be produced in Germany at the time. To generate money and survive these post-war years the Zoo had circus acts and exhibitions of indigenous African tribes. But with support of Duisburg's City Council, Duisburg's public transport company, some wealthy industrials, and motivated citizens, it was possible to make a new start. As important as the money were the animals that came on loan from Munich Zoo - Hellabrun. In fact, these animals formed the genetic foundation of many species in Duisburg Zoo nowadays.
These early years after the war the first geographical grouping of enclosures developed. Furthermore, at the end of the 1940s the monkey house, the aviary and the bear enclosure and big cats enclosure were rebuilt. And in 1951 the former gem of the Zoo, the aquarium, was rebuilt. This 'Haus der Tausend Fische' (House of thousand fishes) is the oldest remaining building of the modern Zoo which connects with the tropical hall. The largest and most expensive asset built in those days was the elephant and giraffe house, which opened in 1953. It still exists, but has been modernised and only houses the Asian elephants. The reticulated giraffes are still close though, in the adjacent enclosure right after the Zoo entrance.
With a steady growth in popularity and number of visitors the Zoo was able to expand again in 1958 with 0.5 ha to the north side of the premises. The sea lion and penguin exhibits were established, and still are located in that part of the Zoo. To build these enclosures, rocks were used from the base of the statue of Emperor Wilhelm that stood on top of the Kaiserberg but was demolished during the war. Further expansion with 5 ha was achieved in 1958 on the other side of the highway. This required a bridge to be built to connect both parts of the Zoo. In co-operation with the Duisburg Steel industry the original pylon suspension bridge of the German pavilion at the World exhibiton in Brussels in 1958 was moved and used to make this connection. Later, this iconic bridge was replaced with a broader landscape bridge that less obviously divides the two parts of the Zoo as the highway and railway beneath is hidden by walls of shrubs and other foliage.
At the 25th anniversary of the Zoo the Zoological Association was conversed into a joint-stock company with the sole purpose to increase the financial possibilities. From then on lots of changes and developments took place.Apart from the enclosures that needed to be established in the new part of the Zoo, new animals needed to be acquired. In those days it was still an accepted procedure to catch animals in the wild. So, in 1961 the Zoo-director Thienemann went for an expedition to the Congo and returned with two okapis. In 1962, the Equatorium was built in the new part of the Zoo, which was the world's largest and most modern primate house at the time. Another highlight of the Zoo's modernisation and progress was the establishment of a scientific department in 1967, and the appointment of an official Zoo veterinarian in 1978.
Duisburg Zoo is well-known for its marine mammals exhibits since 1965 when its first and also Germany's first, dolphin basin or dolphinarium was opened. Dr. Gewalt, director from 1966 to 1993, made every effort to establish Duisburg Zoo as a world leading institution for keeping and breeding of whales and dolphins. And already in 1968 a second dolphinarium was built, this time indoors, which acts as a breeding centre nowadays and is directly connected to the dolphinarium that was built in 1995. The original outdoor dolphin basin was from then on used for white or Beluga whales. The first one was caught in the wild by Dr. Gewalt during an expedition in Canada in 1969. Gewalt organised many expedition during the beginning of his period as director. He went to Africa, Canada, Venezuela and Tierra del Fuego, and braught back everytime new and hardly known species. Something that is out of the question in modern zoo approach, of course. Nevertheless, under the inspiring leadership of Dr. Gewalt Duisburg Zoo was one of the founding fathers of the EAAM, the European Association for Aquatic Mammals. Likewise, Gewalt enabled Duisburg Zoo to engage in dedicated conservational research for dolphins and whales.
Although growth and progress was recorded during the 1970-80s real modernisation took place since the 1990s. Many bar-less, Hagenbeck style, enclosures were created with animals living in their natural habitat or one that closely resembles it. In 1994 the Zoo opened the koala house, and already in 1995 a first Duisburg bred koala was on display. Then and now the first German Zoo to keep koalas. Following state-of-the-art zoo husbandry approaches and exhibit design the Zoo created walk-through / landscape immersion exhibits, such as the lemur island and the new Tropical hall 'Rio Negro'. In addition, the number of species and specimens were decreased to provide the remaining individuals more space. The Zoo's focus on Madagascar manifests itself in the fossa (Cryptoprocta ferox) a flagship species for endangered animals. Duisburg Zoo is co-ordinator of the European Endangered Species Programme for this amazing animal.
A few things atypical for Duisburg Zoo or for any other zoo should be mentioned here. In 1955 a farmstead with horse stables and a horse riding school for children was opened. It was very successful and many children learned to handle and take care of the equine species. Until the 1980s, when it was closed, the riding school was one of the most popular institutions of the Zoo.Another curiosity were the sled dogs acquired during the white whale expedition in Canada. As a result of successful breeding Duisburg Zoo was able to engage in international dog sledding competitions until the end of the 1970s.
Like any modern zoo Duisburg developed a master plan to be ready for the future, to provide the best environment for the captive animals, to engage in relevant conservational research and to educate the public in the best possible way, providing the visitors a real nature/wildlife experience. Several new enclosures have been built the last few years (e.g. gorilla, giant otter, spectacled bear), and others are envisaged (orangutan, coral basin).
(Sources: 70 Jahre Zoo Duisburg by Bielefeld University Zoo Biology Workgroup / Christina Neuenhagen ;75 Jahre Zoo am Kaiserberg by Achim Winkler, 2009)