Allwetterzoo Muenster
ZoORANGerie - Jungle for Orang-Utans

Dag Encke (author)
Monika Fiby (editor, translator)
Richard Perron (editor)

Published 17 Mar 2001



Sentruper Straße 315
48161 Münster
Phone: 0049 251 8904-0
URL: http://www.allwetterzoo.de


Muenster, Munster, Primates, Renovation, Orangutan


Family:Species:Common Name:Capacity:
Mustelidae Aonyx cinerea Asian small-clawed otter 1.1.4
Chloropseinae Chloropsis aurifrons Golden-fronted leafbird 2
Turdinae Copsychus saularis Magpie robin 1.1
Irenidae Irena puella Asian fairy bluebird 2.1
Cercopithecidae Macaca silenus Lion-tailed macaques 3.0
Oriolidae Oriolus xanthornus Black-hooded oriole 2.2
Pongidae Pongo pygmaeus pygmaeus Borneo-orang-utan 1.4
Pycnonotidae Pycnonotus melanicterus Black-crested bulbul 8
Sturnidae Temenuchus pagodarum Brahminy starling 12
Zosteropidae Zosterops consobrinorum Sulawesi white-eye 6


In 1997, planning started for a new orang-utan enclosure on the site of the old polar bear exhibit. The new enclosure forms part of the concept "Allwetterzoo 2000 plus" which will include "four parks in one": primate park, horse and children's park, elephant park and sea park.

The outdoor exhibit for the orangs is structurally varied and contains many plants. A weather-resistant giant root from Alaska, several oak treetops between 8 and 10 m in height and a live 10 m plane tree offer climbing opportunities. Live trees which are not designated for climbing are protected from the orangs with bark-like painted aluminium plates. Moreover, the trees are secured by a special process with tight cables running under the floor, since common tree stabilization with guy-ropes in the air would put the apes at risk. Natural rocks are placed around a waterfall, e.g. Hönnetal limestone and three Vietnamese river marble blocks of 4 to 8 tons, and linked to a landscape of artificial rockwork ending in a water filled moat. This moat forms the barrier between humans and animals just as in the interior tropic hall. The moat is partially filled with gravel to reduce its depth for the safety of the orangs. It is planted to look natural, and is used by the otters that share the exhibit with the orangs and the lion-tailed macaques.

In the tropic hall artificial rockwork is used to create the impression of a natural river bank. Tropical plants line the visitor area and the back of the exhibit. The gap between trees and exhibit barriers is always a minimum of 3.5 m. This is considered to be wide enough, since orangs move hand over hand or swing but do not jump. Electric wire provides additional safety and is placed beyond the normal reach of the orang-utans.

The roof is made from air-filled layers of three transparent Teflon liners. It is supported on round and T-shaped beams reaching 14 m at the highest point. The liners permit 95% diffusion of all light wavelengths supporting plant growth. In addition, the orangs profit from the roof's transparancy when staying indoors for longer periods of time during the winter season. Some roof segments can be opened for ventilation. In order to prevent escapes by the tropical birds inhabiting the hall these openings are covered with a 15mm mesh net. From the outside the entire roof is screened with netting to prevent intrusion by jackdaws and other wild birds.

The kitchen and four boxes for separating individuals, for example before introduction, are invisible to visitors. These former polar bear boxes were slightly adapted for orangs. A fog machine ensures a tropical climate behind the scenes. The kitchen of the old polar bear enclosure has not been changed for the new inhabitants.



The indoor tropic hall covers an area of 500 m2 and is between 8 (eaves) and 14 (ridge) m high. A water filled moat 3,5 m deep and 60 m2 surface area forms a barrier between animal and visitor. The moat is replenished by a stream including a waterfall of 5 m height. The enclosure, formally used for polar bears, measuring 10 to 15 m2 are 4 m high and have been adapted for orang-utans. The exterior pond is 0,5 to 2,5 m deep and receives water from a stream including a waterfall of 4 m height.

Space allocation in square meters:

Use:Indoors:Outdoors:Total Exhibit:



Costs for planting the tropic hall were about DM 70,000.

DM 5,700,000 including 14% for design.



30 September 2000


Beginning: July 1997

  • Consulting for tropical plants: Botanischer Garten der Westfälischen Wilhelms-Universität, Frau Hohmann , Münster, Germany
  • Design, Architecture, Landscape Architecture: Rasbach Architects , Oberhausen, Germany


Beginning: 8 February 1999

  • Artificial rockwork: AAB Atelier Artistique du Beton, Mormant, France
  • Supervision: Rasbach Architekten, Oberhausen, Germany


walter.gif This is a climatic diagram for the closest weather station.



The tropic hall is planted with more than 50 tropic plant species. A tropical gras mix was sewn on the natural ground of the animal area triggering the orangs curiosity. Among the most distinctive plants in the tropic hall are two species of palms, Caryota mitis and Cyrtostachys renda.

The plant list specifies the Latin names of the plants used for this exhibit.


Orang-utans have trees to climb taller than 10 m and about 1000 m3 of accesible space in the outdoor exhibit. Indoors, oak tree tops of up to 9 m are installed in the natural soil, providing about 300 m3 of climbing space. Climbing opportunities high up are much more important for this tree-living species than the indoor ground area of 160 m2.

A water moat serves as a natural barrier between visitors and orangs and as a habitat for their fellow occupants which are Southeast Asian short-clawed otters. In order to prevent drowning accidents the moat is secured with ropes along the edge of the water. Additionally, structural steel was placed in the moat enabling orangs to easily get out of the water should they fall in. Openings, 15 x 15 cm, allow otters to cross the steel frames.

Otters can reach their sleeping box through a pipe from the tropic hall. To get outdoors they use the same exit through bolt doors as the orangs. These doors are kept closed for wheather protection by so called Landois lids and can be easily opened by both orangs and otters. In order to prevent the blocking of an entrance or exit by a dominant animal each of the three areas, outdoor exhibit, indoor exhibit and boxes, have two doors.

Orangs are very skilful and have a lot of persistence. Therefore, all screws in the animal area are specially secured.

The indoor climate simulates the Asian rainforest climate. Indoor temperature is 22 °C by day and 2-3 °C less at night. Humidity is kept around 80%.



The four holding boxes and the indoor exhibit are connected to and separated from the outdoor exhibit by hydraulic and mechanical doors. The system is designed as a full circle to allow individual parts of the enclosure to be isolated,for example for cleaning.



Extensive planting of the tropic hall takes visitors into the world of the tropics and creates an illusion of sharing one space with the animals without barriers. The separating moat is almost imperceptible. A bark covered path takes the visitor on an adventure trail. In order to see the tree living "forest people" climbing freely in the trees a lookout was created in the middle of the tropic hall. On top of an artificial strangler fig, a platform allows visitors to view the animals face to face at 6 m above ground. The strangler fig is a characteristic plant in the Asian tropical forest.

The walk around the outdoor exhibit was designed for exploration. Slopes are densly planted with bamboo creating a jungle-like environment. At a lower spot on the path, visitors can meet orangs on the other side of a glass panel. A trail goes up and down around the exhibit. An alternative path is designed for strollers and wheelchairs. Walking over a hanging bridge visitors can watch what is going on in the water moat. A machine under the bridge creates a jungle atmosphere by producing slow clouds of mist.



A brochure informs about the plants in the tropic hall and explains the importance of the strangler fig and the calamus to the tropical rainforest and their endangered status. A panel at the entrance to the tropic hall depicts the biology of the orang-utan and why the species is vanishing.



The indoor artificial climate is created by using a water fall, sprinklers, a heating system with static radiators in the visitor area, air heating in the animal area and heating pipes in the back wall. Water in the moat is heated to 24 °C from under the floor. This adds to the humidity since the water is hoter than the surrounding air.

Plants are watered with warm recycled water which is distributed by sprinklers under the roof and on the back wall of the exhibit as well as by pipes in the soil. In order to prevent orangs from going outside with wet fur sprinklers are only situated on the back wall of the exhibit.

Transparent 30 mm acrylic doors between indoor and outdoor exhibits provide weather protection and visibility at the same time. For introducing other orangs the acrylic doors between the boxes are exchanged with "howdy fence". Small, 6 mm, openings of this fence minimize the risk of injuries during this critical phase.

After bringing orang-utans and otters together the macaques were introduced in a slow process. The otters run away from the macaques. The orang-utans became friends and interact with the macaques. This introduction is an enrichment for the orang-utans that easily get bored in captivity.



Ansgar Popitz observed the orangs behavior before and after moving to their new enclosure.

Allwetterzoo Münster supports the research project about "longcalls relating to phylogenetic relationship of orang-utan sub-species on Borneo by Marina Davila Ross.



Allwetterzoo Münster participates in the EEP for Orang-utans.

Ecologically friendly material was used to construct the tropic hall, for example PVC-free cables. The exhibit uses computer control to optimize energy saving: Heat is reused by the air heating system and the static radiator heating takes account of open windows. Heated water from the moat is re-used to water the plants. The building is insulated with 10 cm of outer skin.



Local German oak was used for timber.



© Allwetterzoo Münster, 1999


Site Plan

Site Plan

© Rasbach Architekten, 1999


Picture Views

Picture Views

© Rasbach Architekten, 1999




© Allwetterzoo Münster, 2001


Enrichment for orang-utans

1. Enrichment for orang-utans

© Bärbel Uphoff, 2002


Otter and macaque

2. Otter and macaque

© Bärbel Uphoff, 2002


Orang and Otter

3. Orang and Otter

© Christoph Matzke, 2001


Outdoor exhibit

4. Outdoor exhibit

© Monika Fiby, 2001



5. Waterfall

© Monika Fiby, 2001


Tree protection

6. Tree protection

© Monika Fiby, 2001


Live plane-tree

7. Live plane-tree

© Allwetterzoo Münster, 2001


Ropes for climbing

8. Ropes for climbing

© Allwetterzoo Münster, 2001


Hanging bridge

9. Hanging bridge

© Allwetterzoo Münster, 2001


Tropic climate

10. Tropic climate

© Allwetterzoo Münster, 2001


Viewing window

11. Viewing window

© Allwetterzoo Münster, 2001


Face to face with an Orang-utan

12. Face to face with an Orang-utan

© Allwetterzoo Münster, 2001


Entrance to the tropic hall

13. Entrance to the tropic hall

© Monika Fiby, 2001



14. Seating

© Monika Fiby, 2001


Water moat

15. Water moat

© Allwetterzoo Münster, 2001


Access to the observation tower

16. Access to the observation tower

© Monika Fiby, 2001


Viewing platform

17. Viewing platform

© Monika Fiby, 2001


View from the platform

18. View from the platform

© Allwetterzoo Münster, 2001


Climbing trees in the tropic hall

19. Climbing trees in the tropic hall

© Allwetterzoo Münster, 2001


Living up high

20. Living up high

© Allwetterzoo Münster, 2001


Feeding place for birds

21. Feeding place for birds

© Monika Fiby, 2001



22. Kitchen

© Monika Fiby, 2001


Orang-utan box

23. Orang-utan box

© Monika Fiby, 2001


Otter box

24. Otter box

© Monika Fiby, 2001


Section of the exhibit

25. Section of the exhibit

© Rasbach Architects, 1998


Polar bear exhibit

26. Polar bear exhibit

© Allwetterzoo Münster, 1996