Appeal to Relocate the Bird Park and Eco-lodge in the Proposed Mandai Project

The proposed Cross Island MRT Line will cut across our Central Catchment Nature Reserves (CCNR) on the southern corner in the Thomson area. Whilst waiting anxiously for the verdict on whether this line will be re-routed to avoid the nature reserves or will cut through it as proposed, I was shocked to hear another announcement about the development of a 126 ha mega-attraction at Mandai. This development is slated to be built adjacent to the CCNR on its northern front. These two developments would significantly affect the biodiversity in the CCNR.

The plans for these two major projects raise questions about Singapore’s commitment to protect our nature reserves. The CCNR takes up only about 4% of our total land area. With the Bukit Timah Nature Reserve, they are our treasure trove of biodiversity, something unique to our city that other cities in the Northern hemisphere are not able to boast of. Singapore is one of four biodiversity hotspots overlapping Southeast Asia[1].

nature reserve fragment 16

Source: Sodhi, N. S. et al., 2004. Southeast Asian Biodiversity: An Impending Disaster. TRENDS in Ecology and Evolution Vol.19 No.12 December 2004


These are areas that contain high densities of endemic species and have undergone immense habitat loss through the years. We have lost more than 95% of our land and freshwater species over 183 years[2]. Despite this, we still have a healthy and diverse number of species that is rare in any built-up city and which need our protection.

nature reserve fragment 17

Source: Chart edited from the paper Sodhi, N. S. et al., 2004. Southeast Asian Biodiversity: An Impending Disaster. TRENDS in Ecology and Evolution Vol.19 No.12 December 2004


The recent Festival of Biodiversity organized by NParks and supported by many volunteer groups highlighted our rich biodiversity and the passion of our younger generation to conserve it. Their enthusiasm was a testimony of how passionate and proud they are of our natural heritage. Increasingly, this has led to more ground up and government initiatives to protect certain endangered species in Singapore. These initiatives have a chance to succeed only if the species’ natural habitats in our nature reserves are not further diminished or disturbed through development around our nature reserves.

We must reconsider allowing the building of the Bird Park and Eco lodges with the swimming pool and spa in the new Mandai project. I am not against the expansion of the Mandai attractions per se. The Rainforest Park, if planned sensitively with minimum clearing of forests and low controlled human traffic, could be well placed to promote interaction with nature and environmental education. The arguments in this letter are based on my personal observations and research from scientific sources.

The intention of Mandai Park Holdings (MPH) to build additional attractions will have 6 major consequences, given that these developments would be located next to the nature reserve. They are:

  1. Increased chances of zoonoses i.e. transmission of diseases from animals to humans
  2. Increased human footprint
  3. Habitat loss
  4. Loss of buffer zones
  5. Reduced contiguity of natural movement of wildlife
  6. Introduction of foreign flora and fauna species


Increased chances of zoonoses

Jurong Bird Park is an urban park. Public feedback has raised many concerns about the building of the park next to the nature reserves. The plan to build nine aviaries where visitors are free to roam among free flying birds is an attractive one. However, it would lead to increased interaction between captive birds and humans, a situation that needs to be carefully monitored in view of the global emergence of infectious diseases.

Scientific literature has shown that domesticated animals are a reservoir of infectious agents that can pass to the wildlife population and vice versa. Wildlife plays a key role in this emergence as it provides a “zoonotic pool” from which previously unknown pathogens may emerge.[3] Great measures must be taken to ensure that viruses and other parasites do not pass from wild to captive birds, and thereafter to humans or vice versa. Building the Bird Park next to the nature reserves will increase the interaction between wild and captive birds, something that is not observed in its present Jurong location, as it is not next to a nature reserve. Will the new Mandai Bird Park be a potential hotbed for emerging infectious diseases?

Spread of emergening infectious diseases

Fig. 1. The host-parasite ecological continuum (here parasites include viruses and parasitic prokaryotes). Most emerging diseases exist within a host and parasite continuum between wildlife, domestic animal, and human populations. Few diseases affect exclusively any one group, and the complex relations between host populations set the scene for disease emergence. Examples of EIDs that overlap these categories are canine distemper (domestic animals to wildlife), Lyme disease (wildlife to humans), cat scratch fever (domestic animals to humans) and rabies (all three categories). Arrows denote some of the key factors driving disease emergence. Source: Peter Daszak, Andrew A. Cunningham, Alex D. Hyatt. Emerging Infectious Diseases of Wildlife Threats to Biodiversity and Human Health.


It was just over a decade ago that Singapore experienced the avian influenza pandemic. We may not have a large domestic poultry farm issue to contest with, but building several large captive avian attractions may encourage another mode of transmission that Singapore has not encountered before. The attraction will put people in increased contact with previously unfamiliar microbes or their natural hosts and promote their dissemination.

The concern is not just with the Bird Park but also with the planned Eco-lodges within the attraction. We will not only increase the numbers of contact but also prolong the duration of such interactions, thus encouraging the introduction of viruses, as well as its dissemination through physical contact or vectors such as mosquitoes.

In 2009, the Ministry of Home Affairs released a document on “Preparing for a Human Influenza Pandemic in Singapore”[4]. This document spelled out strict biosecurity measures where local poultry farms have to bird-proof their poultry houses to prevent any contact between migratory birds and poultry. The proposed bird park at the Mandai area will have aviaries that are enclosed by netting that allow wild birds and bats to come into direct contact with the nets.

Nature reserves like Sungei Buloh Wetland Reserves are built in a way to prevent visitors from having close contact with wild birds. They are all observed from a distance. Wild birds in our forests are small in numbers, usually hidden and high up in the forest canopy, requiring patience and expertise to spot them. These measures make them low risk areas of transmission of diseases unlike the aviaries in the proposed Mandai Bird Park.

The MHA has stated that they “recognise the emergence of new strains of avian influenza as a grave threat to public health and national security”. Is it worth the great risk of building the Bird Park next to the nature reserves as opposed to building it in a less sensitive area away from wildlife? Is this risk worth the potential revenue generated by clustering all the nature attractions into a mega nature attraction in Mandai?

The recent outbreak of Zika indicates that the public is very concerned about mosquito transmitted diseases and justifiably so. Any small possibility of catching an infectious disease through contact with birds or from mosquito bites would put visitors off visiting any one of the attractions. Is it strategic to locate all the attractions together in light of emerging infectious diseases? Is putting all the eggs in one basket so as to generate revenue wise?

Increased human footprint

With the plan to increase visitorship to the mega Mandai attraction by four times, the human footprint would be greatly increased. A visitorship of a projected 14,300 visitors a day at its peak would create stress through the greater demand for public and private transport, F&B space and air-conditioning. These demands would result in an increase in noise, sound, dust, light and temperature (island heat effect phenomenon) that would affect the neighbouring nature reserves.

The mode of action of crystal toxins from an entomopathogenic bacteria Bacillus thuringiensis serovar. israelensis Source: Microorganisms in Biological Pest Control — A Review (Bacterial Toxin Application and Effect of Environmental Factors) In 2015, InTech marked its 10th anniversary since publishing the first book. In these 10 years we published some exceptional research, and to highlight this, we complied the Research Collection Books containing the leading chapters on a specific research topic. The chapters have been selected following different criteria, among which are the number of downloads of a chapter, the number of views, readers feedback and citations. In celebration of our 10th year anniversary, and to thank our authors for their contributions and acknowledge the specific merit of their work, their chapter has been included in one of our Research Collection Books. Note: The Research Collection books are to be found in our Book Catalog in order to avoid duplicating chapters in our reading platform. By Canan Usta

The mode of action of crystal toxins from an entomopathogenic bacteria Bacillus thuringiensis serovar. israelensis
Source: Microorganisms in Biological Pest Control — A Review (Bacterial Toxin Application and Effect of Environmental Factors)

With an increase in human traffic, effort to control vectors such as mosquitoes will also increase in frequency and number. MPH have indicated that they will use misting of bacteria, Bacillus thuringiensis var. israelensis (Bti), for mosquito control. The bacteria target the insects mainly from the order Diptera (flies), which affect not only mosquitoes but also other midges, gnats and flies. These insects play different and important roles such as pollinators in our ecosystem in the forests. Increasing the frequency and volume of bacterial misting may harm the natural populations of other insects in the nature reserves adjacent to the attractions. Besides terrestrial insects, water fleas exposed to these bacteria strain have been shown to experience moderate toxicity[5]. As the attractions are right by Seletar Reservoir, we would need to consider the possibility that other aquatic invertebrates may also be affected. The Mandai Zoo has been using this method of misting for mosquito control. I sincerely hope that stringent checks have been conducted on their vendor that administer these Bti as the Bti would inevitably end up in our reservoir water and also the CCNR ecosystem.

Have studies been conducted to show that the Bti has no short and long-term significant effect on our various local insect populations and the invertebrate populations in the reservoirs and natural streams in the nature reserve?







Habitat loss

It is a fact that forested areas will be lost for the development as about 35.4 ha of area that hosts existing natural habitats will be cleared. It is not just about cutting down trees and clearing vegetation. It is about the removal of habitats which different animals depend on for food, shelter and protection. A total of 55 locally threatened animal species were recorded in the area according to the STB’s survey report. This will impoverish our valuable natural heritage which is already steadily declining through the years.

Mandai Developed Site

Loss of buffer zone

The buffer zone for the northern sector of the CCNR will be lost. Besides grassland, this consists of mature secondary forest. The buffer is especially important against sudden microburst storm events, such as the one that damaged10,000 trees in a 40 ha area stretching from Lorong Lada Hitam to Mandai Lake Road in March 2011. Greater devastation may occur as more areas are cleared for the Mandai development.

Buffer zones have the following functions. They:

  • Form a physical barrier to human encroachment
  • Protection nature reserves from storm damage
  • Enlarge the natural habitat for the wildlife in the reserve
  • Reduce edge effects e.g. drying of the forests,
  • Enhance the environmental services provided by the reserve
  • Reduce stress on wildlife and conflict between wildlife and humans

The buffer zones may not be sites of active biodiversity conservation, but their establishment provides an additional layer of protection to existing areas of biodiversity importance, and they are often fundamental to achieving conservation of those areas. They are important for the conservation of species that are highly mobile. The proposed buffer is only 25 m in the Rainforest Park South and 45 m in the Bird Park. A wider buffer must be maintained.


Reduced contiguity by narrowing wildlife corridor

As the CCNR is already fragmented, animals have to transverse from one of the fragments adjacent to the Night Safari to get to the other fragment of the CCNR. This connectivity of a natural passageway will be further reduced by the planned development. The current unrestricted movement of the animals between the two fragments will be blocked by the fences of the extensive development. Even the proposal by MSH to build a narrow 45 m wide Eco-Link would not mitigate the greatly reduced movement of wildlife, which is integral to maintaining a healthy ecosystem in our forests.

Mandai development affects wildlife corridor

Introduction of foreign flora and fauna species

Mitigation measures have been suggested by MSPH to ensure that exotic flora and fauna species specifically housed in the attraction will not escape into the surrounding forests. The fact remains that it is next to the nature reserves and the risk of our biodiversity in the nature reserve being affected by any flora and fauna escapee is high. We have failed to heed certain examples that already exist in the annals of our natural history. Wild populations of an invasive plant, Cecropia pachystachya, may have originated from the introduction of this plant to the Singapore Zoo in 1992 as food for sloths[6]. The Cecropia has in turn out-competed our native Macaranga species and is now very common in habitats that were once dominated by Macaranga species. Another illustration is that of a lizard, the brown anole, which was introduced with plants at the Gardens by the Bay, and which has now established a feral lizard population in Singapore.[7]

We demonstrated resourcefulness and creativity in building a world-class attraction, the Gardens by the Bay, in a barren piece of reclaimed land. The same can be applied to the new Bird Park. In the MSPH’s plan, all the ecosystems for each aviary in the Bird Park will be artificially created. Vegetation in the existing Mandai site will be cleared to build these aviaries. Why not choose a less sensitive site away from nature areas instead? This could save resources on the mitigation measures and also reduce the risk of zoonoses.

I applaud the MPH for engaging nature groups and for making changes to their plans based on feedback from the engagement. However, even if measures are taken to mitigate the environmental impact arising from such a development, there is still impact that is significant to the nature reserves immediately and in the long run. If we continue to fragment our precious nature reserves and encroach on the borders of the CCNR, our biodiversity will be threatened and we will slowly lose this rich gene pool. We should protect what little we have left and conserve it fiercely with zero tolerance on any impact for our future generations.

I sincerely hope that alternative locations or strategies can be developed when building the Bird Park and Eco lodges, in view of all the concerns raised here.


[1] Sodhi, N. S. et al., 2004. Southeast Asian Biodiversity: An Impending Disaster. TRENDS in Ecology and Evolution Vol.19 No.12 December 2004

[2] Brook, B. W., Sodhi, N. S. & Ng, P. K. L. 2003 Catastrophic extinctions follow deforestation in Singapore. Nature 424, 420 –423. (doi:10.1038/nature01795)

[3] Peter Daszak, Andrew A. Cunningham, Alex D. Hyatt. Emerging Infectious Diseases of Wildlife Threats to Biodiversity and Human Health. SCIENCE Vol 287 21 January 2000

[4] Preparing for a Human Influenza Pandemic in Singapore Ministry of Home Affair, 01 Jan 2009

[5] National Pesticide Information Center, Bacillus thuringiensis General Fact Sheet, 2015

[6] A. F. S. L. Lok, K-x. Tan, K. Y. Chong, T. P. L. Nghiem and H. T. W. Tan, 2010. The Distribution and Ecology of Cecropia species (Urticaceae) in Singapore. NATURE IN SINGAPORE 2010 3: 199–209

[7] Heok Hui Tan and Kelvin K. P. Lim. 2012. Recent Introduction of the Brown Anole norops sagrei (Reptilia: Squamata; Dactyloidae) to Singapore. NATURE IN SINGAPORE 2012 5: 359–362


Postscript note:

AVA employs a variety of local control measures against HPAI[1]. These include biosecurity, biosegregation, surveillance, vaccination, removal of backyard poultry, improvement of diagnostic laboratory capability and public education. However, the corner stones for AVA’s control measures are biosecurity and enhanced surveillance.


Biosecurity is considered the most important tool to prevent and control AI.1,16 The key is to keep migratory wild birds (especially water fowl) away from poultry and commercial bird breeding operations. AVA emphasizes biosecurity at all local poultry farms, poultry slaughterhouses, bird holding and breeding premises, zoological gardens and bird parks.

AVA defines biosecurity measures as measures to keep disease (specifically HPAI) out of local poultry farms, slaughterhouses and bird breeding premises. AVA has imposed strict biosecurity measures for local poultry farms and poultry slaughterhouses. For poultry farms, biosecurity measures are mandatory and annual farm licenses are only issued if the farm can demonstrate adequate biosecurity measures. These measures include:

  1. a) Complete perimeter fencing for all poultry farms and slaughterhouses;
  2. b) Bird proofing for all poultry houses;
  3. c) Disinfection facilities for personnel and vehicles;
  4. d) Restriction of access to premises including restriction of casual visitors.

Extract from: Hon Keong Leong, et. al. 2008. Prevention and Control of Avian Influenza in Singapore. ANN ACAD MED SINGAPORE 2008;37:504-9

[1] HPAI – refers to the most virulent form of AI known as highly pathogenic avian influenza.

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