The Role of Architectural Design in Promoting the Social Objectives of Zoos

A Study of Zoo Exhibit Design with Reference to Selected Exhibits in Singapore Zoological Gardens

by Michael Graetz

PART 2 - PHYSICAL ELEMENTS OF ZOO DESIGN

2.7 Habitat Lighting

The term, ‘habitat lighting’ was coined during the conceptual development of the ‘Night Safari’, an animal related theme park developed and managed by the Singapore Zoological Gardens as a separate entity to Singapore Zoo. The Night Safari is opened to the public only at night and its unique feature is thus the manner of presentation of (nocturnal) animals which, in design terms, is primarily (but not solely) manifested as novel lighting design. This chapter focuses on aesthetic principles; while technical aspects are referred to, these are not dealt with in detail. Lighting in relation to daytime zoological displays is also discussed using examples from Singapore Zoo.

Use of Lighting by Day

Four special situations are encountered in zoos where artificial lighting is required or used by day. These are: 1) Displays needing supplementary lighting; 2) Indoor displays without daylight; 3) Glass fronted exhibits prone to reflection; and 4) Daytime nocturnal exhibits.

The first situation is the most often encountered in Singapore Zoo where it occurs mainly in fish and terrarium type reptile exhibits. Supplementary lighting is only effective in overcast, shaded or twilight conditions, each of which may occur daily, seasonally or irregularly. It differs from the second, indoor situation in that there is natural ambient daylight and it is a less controlled situation. Purely supplementary light also does not interfere with the natural daylight period [1].

day lighting
Fig. 58 Lighting array including plant growth lights for a fish display

The third case, control of reflections caused by bright light sources or illuminated (sunlit) areas on the visitor's side, is possibly a greater problem in warm climates due to the need for larger openings in naturally ventilated shelters. Reflections are rarely controlled purely by artificial light because sunlight is so much brighter than any economic artificial lighting solution. It can work when both exhibit and public sides of the glass receive almost equal amounts of daylight. If this can be kept low enough, then artificial light in the exhibit may tip the balance so that viewers do not see reflections.

The fourth, nocturnal houses, comprise a special category where the day-night cycle for the animals are reversed. From the visitors' viewpoint, the quality of light used to reverse the ‘daylight’ hours for the animals is irrelevant, only the quantity required (out of exhibit hours) to allow enough light for the animals to be seen without disturbing their nocturnal activity.

snake jewel box exhibit
Fig. 59 Daylight is the cause of reflections on this snake terrarium. The sign light has a controlled beam and angle

From the fore-going, it is apparent that lighting for some functional (including biological functions) and aesthetic purposes is of greatest relevance in Singapore and hence in similar zoos. Generally, it ought to be possible to combine these purposes in a well-considered lighting design.

Some examples of artificial lighting in Singapore Zoo are as follows:

These various uses are not untypical of lighting practices in all zoos. Fluorescent light, is used for its economy which can be a poor justification for the flat, shadowless impression and poor colour rendition it gives [2]. These characteristics can be turned to advantage, however. Fluorescent light in general provides an even, ambient light which ensures there are no too-dark corners, while incandescent point sources and focused spots may provide highlights and good colour rendition [3]. This is often the case in zoos except that relatively unfocused lamps are used. Commonly, fluorescent battens are included in the design, while ‘heat’ lamps are placed by the curatorial staff after construction.

This rather simplistic account of the use of lighting ignores the many more technical factors to consider, and the diversity of situations, philosophies and technologies. It then becomes unwise to lay down principles. For example, from a purely visual standpoint, exhibit lighting can be treated naturalistically or theatrically. Similarly, colour can be rendered naturalistically or not [4]; or an exhibit can be made unnaturally bright or be lit with directed light to create strong shadows; or it may be the concern of the designer to show animal forms explicitly with uniform light (however, some degree of shading or modelling is desirable). Light coupled with interior finishes, colours and careful control of shadows is also used to create illusions of infinite depth in indoor displays, however this has not been used in Singapore Zoo. [5]

Lighting in diurnal zoos is a case of rather eclectic styles and technologies at present. It has specific problems and requirements so that other, well established fields such as museum, art gallery and theatre lighting can only provide starting points. These applications have specific lamps and luminaires designed for them and their use is only slowly explored by zoos. In the case of Singapore Zoo, this has largely been due to the lack of a need for lighting in the majority of exhibits and the fact that the available lighting models have always come from zoos with a high proportion of indoor displays.

In the case of the Night Safari, considered next, an entirely new model had to be created and therefore it can be described with much greater comprehensiveness and certainty.

Lighting Principles in the Night Safari

In approaching the Night Safari, the only available lighting model consisted of the practice in many game reserves and national parks of floodlighting a waterhole, or spotlighting animals from a vehicle at night. Another model that was considered initially was that of fixed, high masts with large and powerful lighting arrays, similar to the masts seen in stadiums (though the similarity was only recognised later [6]).

The distinction between habitat lighting design and engineering lighting design is not universally accepted, as was revealed by the discussion following a paper by Cansdale presented at the second symposium on zoo design held at Paignton, England. Cansdale states: “Lighting is a severely practical matter and not one to be handed over to ‘artistic types’.”[7], which drew this rejoinder:

The purpose of lighting in a zoo was not to satisfy photo-electric cells and meters; . . . . an artistic type should be in control of the lighting. The lighting had to be placed, so that contrasts were under control, and shadows had to be formed, so that the human eye could see and recognise what was in the exhibit. . . . The basic purpose . . . was not necessarily electrical efficiency. [8]

The principle lighting tasks in the ‘Night Safari’ are as follows:


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