Dublin Zoo
Gorilla Rainforest

Monika Fiby (Author for ZooLex)
James Creighton (Author for Dublin Zoo)
Jonas Homburg (Editor for ZooLex)
Stephen Butler (Editor for ZooLex)

Published 21 Mar 2019


Phoenix Park, Dublin 8, Ireland
Phone: +353 1 4748900
URL: http://www.dublinzoo.ie




Family:Species:Common Name:Capacity:
Ceropithecidae Cerocebus torquatus Red-capped mangabey 4,0
Hominidae Gorilla gorilla gorilla Western lowland gorilla 2,4 + young


Gorilla Rainforest is part of a masterplan that was prepared in 2008, changing the face of the zoo from formal gardens to habitats for wild native and captive exotic species. The exhibit was designed with the intention to breed gorillas and to recreate their natural habitat as closely as possible. The breeding group of seven gorillas may grow in size to between 12 and 15 gorillas.

An island of about one hectare is available for the troop and a group of male mangabeys that share the outdoor space with the gorillas. The landscape is a series of 4 ridges 4m high, with 2 larger flat areas. This undulating topography and the planting were inspired by the lowland rainforest of western Africa. The design was influenced by behavioural studies of gorillas in the wild. High elevations and trees allow the apes an overview of the surrounding landscape, while flat areas and dense vegetation allow the gorillas to forage and move to private resting spaces. Visitors are immersed into the outdoor environment on a winding path along the south side of the island, off the main path. They have access to a large shelter with a viewing window into a valley of the island.

The water moat surrounding the island is 4m deep with a concrete vertical boundary at the visitor side and has a gently rising slope and a broad shallow water part towards the animal side. A strong plastic mesh covers the entire slope to assist animals getting out if they fall in, visually hidden by water plants where possible.

The holding building is hidden behind vegetation at the small end of the island. It includes a viewing area for visitors into the central holding space for gorillas, gorilla separation enclosures, kitchen, keeper room and enclosures for the mangabeys. Heating and air conditioning is by ventilation. Separation boxes have additional panels for heating. Windows are opened manually. Temperature in the holding building is kept between 28 and 30 °C.



The holding building is 650m² and includes a kitchen with 18m², a visitor space with 50m², 4 gorilla separation boxes, each 12m², a large box with 24m² and a shift cage with 4m²; 2 monkey separation boxes, each 9m² and an indoor holding area of 260m². Outdoors, the animal area is 4360m². It is surrounded by a 5m wide water moat covering about 1430m². The visitor path is 3 to 4 m wide and covers about 1400m² including viewing areas and a viwing shelter with 30m². The service yard is about 100m².

Space allocation in square meters:

Use:Indoors:Outdoors:Total Exhibit:



€ 3,200,000



28 September 2011


Beginning: 2009

  • Design: Jones & Jones, Seattle, USA


Beginning: September 2010


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



1,200 tons of standard topsoil was placed in the exhibit after the initial landscaping to provide ideal conditions for plant growth. Any larger stones near the surface were removed. To reduce soil compaction near the gorilla house manufactured urban soil was used, with crushed tyre rubber as aggregate to avoid any stones. All shrub and tree plantings were mulched with tree chippings and most of the planting was done during summer when the plants were in full growth.

The intentions of the plant concept were to avoid simple grass but instead to form a stimulating habitat and make use of plants as important behavioral enrichment. So, both edible plants for the gorillas and also non-edible ones that would not be damaged too much to form cover, shade, shelter or screening were used. Only 3 young specimens of Pterocarya fraxinifolia were protected with hot wire to aid establishment.

The large flat areas, near the visitors for viewing, have mainly edible plants, - grasses, or hay meadow plants, - with herbaceous plants on the slopes of the mounds, and trees and shrubs on top, with variations in all areas to make it all appear natural and to have plants that blossom at various times of the year. Low areas between the mounds, and the moat edge, were planted with water loving plants. Approximately 200 plant species were used, and about 15,000 actual plants were planted. Large oaks on the island were maintained and are used by the animals, particularly by the mangabeys.

With the West-African Mbeli-Bai as inspiration, the visitor trail is closely planted with trees, so eventually visitors will look out from under the trees across the moat to see the gorillas. Tall growing herbaceous plants give a lush appearance, and for varied aspects, some areas have lower growing plants to allow viewing. As part of the zoo’s overall thematic landscape master plan this area, and only this area, has some purple leaved plants. Tree selection was a mix of cheap and easy Platanus orientalis for immediate effects, with smaller specimens of Catalpa x erubescens ‘Purpurea’, many Populus lasiocarpa, and a mix of some large specimens of Liriodendron tulipifera (with a uniquely shaped leaf) with 200 small ‘whips’ as well, many of which will need to be coppiced every few years.

The grass in the valleys of the island is kept short by mowing three times per year. Some parts of the moat need growth control, so the plants do not encourage the gorillas to enter the water. Nettles are pulled manually about 6 times a year by 5 to 7 keepers working together at night when animals are indoors. Annual thistles are no longer a problem after they were removed in the first year.

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


The island has an undulating topography that allows animals to retreat from each other and choose sun and wind exposure. The exhibit is structured by dead trees and fallen logs serving as climbing opportunities and outlooks for the gorillas and the mangabeys. Two large existing trees, an oak and a chestnut were included in the enclosure and can be climbed by the monkeys. Woodchip beds arranged on a heated ground plate in front of the viewing shelter provide comfortable resting opportunities for the gorillas while being protected from the weather. Scatter feeding encourages movement around the enclosure. Many plants on the island are edible and regrow sustainably such as Plantago lanceolata, Trifolium repens, Carex pendula and Taraxacum officinale.

Indoors, there is one large indoor enclosure for the gorillas visible to the public. Behind the scenes there are one large and four smaller separation cages that can be connected among each other and to the main room. The largest isolation cage has a window to the main exhibit, so if an individual is introduced or has to be temporarily separated it can stay in visual contact with the rest of the group.

The main indoor animal space is structured by lots of trunks that are fixed to a concrete base and screwed to a horizontal metal grid that is built about 2 meters under the ceiling with its skylights, light and sprinkler fixtures. The metal grid is accessible for the keepers who can fix items such as swings and ropes to it. Particularly in the corners of the room the ropes offer escape routes for chased animals. Many of the trunks have bases of branches that the gorillas can use for perching. The whole space is usable in three dimensions thanks to the trunks, the ropes and the metal grid top.

10 metal brackets with screws on the ground and at the walls allow the keepers to fix branches of silver birch and willow for browse and for screening. During the winter, when the animals spend more time indoors, branches of evergreen trees are used for creating screens that give the animals more privacy.

The concrete floor is covered with a layer of wood chips of about 20 centimeters. These are sprinkled, turned over and sprinkled again about once a week and fully exchanged two to three times per year. This proved more suitable than deep mulch from bark that easily builds up mold in the humid climate of Ireland. Four drains of about 60x60 cm in the floor are sufficient for this purpose.

Nipple drinkers on the wall are available for the apes. The drain along the separation boxes is open and has a loose strainer. This part is big enough that the gorillas cannot pull it through the mesh of the door into their box. Each separation enclosure has a raised wooden platform. They are usually all open to the main room so that animals can choose where to rest.

Feeders are fixed to some of the trunks and to the wall. The release of food is operated by the keepers sending a message from their mobile phone. This way they can use them to alleviate aggression in the gorilla group by offering them another focus.

The mangabeys have their own indoor enclosure neighboring the main gorilla room by metal grid doors and two separation cages furnished with tree stems, branches and ropes.



All shift gates to the outside and between the main room and the separation cages are horizontal and electrically operated. The bluetooth remote control allows the keeper to walk to the best location for visual control of the slide that they operate. The horizontal shift gates between the separation boxes are mechanically operated by hand and secured by a lock. The mangabey cages have vertical slides manually operated by cable control.

A small cage serves as a transfer chute between the main indoor enclosure and the largest separation cage. There a transport box can be fixed to one slide located at ground level (while the other slides are slightly elevated). Both for the gorillas and the mangabeys, there is a transfer cage to the outdoor enclosure connected by a slide to the main indoor rooms and to the separation cages. The primates are used to regularly pass through this cage so it can also be used for individually getting animals in for training or medical treatments.

The doors to the gorillas’ and the mangabeys’ rooms are secured by double bolts fixed with a lock. The main door leading to the large indoor enclosure has a metal box mounted to the inside with a grid at the bottom and a bar door that can be opened from outside, so food or other items can be put into by the keepers and pulled out by the apes.

Keepers can supervise all cameras in and around the enclosures from their mobile phone and remotely operate the feeder boxes from their phones.

The kitchen has a window to the visitor indoor space and to the animal indoor space. Both windows can be screened when needed.



Visitors enter Gorilla Rainforest on a winding path off the main path. They pass by a waterfall and walk through lush vegetation along a small creek until they reach an open space with a view of the island that is home to the gorillas and mangabeys. Visitors can see the animals from a distance across the water moat and up close at the window of a large shelter. The animals like to spend time in front of the shelter since the floor is heated and the roof overhang protects them from rain.

Indoors, the visitors can view the main gorilla enclosure through a large viewing window from a room also providing educational signs.



Signs inform visitors about the biology of gorillas and the family relation of the individuals kept at the zoo. A large upright gorilla drawing illustrates the similarity of physiology in gorillas and humans. A mirror next to it adds a humorous feature. Information panels highlight the threats facing the western lowland gorilla in the wild and how the zoo contributes to the conservation of this species.



Two keepers are in charge of the gorillas and the mangabeys. They get assistance from other keepers when needed.

A vehicle can go through large gates into the building and further to the exterior space for maintenance and transport of animals. The animals receive crate training in the separation enclosure that is used for fixing the transportation box. An enclosure next to it can be used for introduction since it has a window to the large community room.



Dublin Zoo supports research on gorillas in Congo and informs its visitors about the project in its newsletter.



Western Lowland Gorillas are part of the conservation breeding programme (EEP).



The water moat is toped up with water from the existing neighboring lake via a weir.



© Dublin Zoo, 2018


Site Plan

Site Plan

© Jones & Jones, edited by Jonas Homburg, 2018


Picture views

Picture views

© Jones & Jones, edited by Jonas Homburg, 2018


Silverback harvesting

Silverback harvesting

© Stephen Butler, 2011


Way towards the exhibit

1. Way towards the exhibit

© Monika Fiby, 2018


General view of the gorilla island

2. General view of the gorilla island

© Monika Fiby, 2018


Gorillas in lush vegetation

3. Gorillas in lush vegetation

© Stephen Butler, 2011


Viewing across the water moat

4. Viewing across the water moat

© Stephen Butler, 2013


Water moat during construction

5. Water moat during construction

© Stephen Butler, 2011


Viewing shelter

6. Viewing shelter

© Monika Fiby, 2018


Gorillas close-up

7. Gorillas close-up

© Monika Fiby, 2018



8. Landscaping

© Monika Fiby, 2018


Mangabeys in the tree

9. Mangabeys in the tree

© Monika Fiby, 2018



10. Signage

© Monika Fiby, 2018


Interpretive panel

11. Interpretive panel

© Monika Fiby, 2018


Holding building

12. Holding building

© Monika Fiby, 2018


Entrance to the gorilla house

13. Entrance to the gorilla house

© Monika Fiby, 2018


Indoor viewing

14. Indoor viewing

© Monika Fiby, 2018


Main indoor room

15. Main indoor room

© Monika Fiby, 2018


Gorillas indoors

16. Gorillas indoors

© Monika Fiby, 2018


Transfer cage

17. Transfer cage

© Monika Fiby, 2018


Feeding box

18. Feeding box

© Monika Fiby, 2018


Separation cages

19. Separation cages

© Monika Fiby, 2018


Slide operation

20. Slide operation

© Monika Fiby, 2018


Passage to outdoor exhibit

21. Passage to outdoor exhibit

© Monika Fiby, 2018


Access to the roof grid

22. Access to the roof grid

© Monika Fiby, 2018


Mangabey cages

23. Mangabey cages

© Monika Fiby, 2018


Gorillas at the waterfront

24. Gorillas at the waterfront

© Stephen Butler, 2011