Private property as sites for urban ecology studies

The urban vegetation makes up a big component of the biotic urban environment. As we have learnt during our lectures, the distribution of urban vegetation can vary with landuse— streets, parks and privately owned lands. In Singapore, most of the trees are found along the streets and in parks. A small proportion of urban vegetation is owned privately within housing estates, schools and hospitals. Despite being a small proportion, these vegetation usually have vastly different species composition from street trees that are planted and managed by authorities. On private land, we often find plants that are either visually appealing or have edible parts (e.g. fruit trees, vegetables or spices). Ecologically, these urban vegetation might play a different functional role from street trees and can serve to attract wildlife such as various insect pollinators, birds and mammals on privately owned lands.

Examples include, birds such as oriental pied hornbill (Anthracoceros albirostris), rainbow lorikeet (Trichoglossus haematodus) and Brown-throated Sunbird (Anthreptes malacensis) feeding on rambutan (Nephelium lappaceum) fruits in the gardens of private houses.

Bats have also observed to be attracted by the fruit trees planted, and have been recorded to roost in porches. In this instance the owner was rather curious about them and observed and recorded some of their behaviour for quite some time, including licking wooden stips on the roof of the porch for salt. However due to the mess from their leftover food and excrements left behind, they were eventually discouraged to roost (aka chased away) with a bag of chilli.

In other instances, Khoo Teck Phuat Hospital (KTPH) features many host plants of different butterflies, attracting various butterfly species. One such plant is the Aristolochia tagala which is an exotic species that is not found commonly in Singapore, but is a host plant to the common birdwing (Troides helena) and common rose (Pachliopta aristolochiae). This allowed a common rose population to establish and flourish in KTPH during certain years, and was one of many privately owned study sites where Justin studied this butterfly species for his FYP. Justin’s study was unique because it had many private sites as he was targeting a unique host plant that is usually found on privately owned land. However, broader urban ecology studies often overlook privately owned land as shown by a lack of ecological data in many aspects on privately owned land in many cities. Furthermore, urban landscapes are often heterogeneous and various ecological processes such as nutrient cycling, soil organic carbon, wildlife interactions could possibly be different between private and publicly owned land.

Therefore ecological research in various aspects on privately owned lands is necessary but lacking. Hopefully there will be more urban ecology studies on private properties in Singapore in the future. Do check out this paper, which provides some great advice on conducting urban ecology studies on private properties, the frequently cited concerns of researchers and their potential solutions.

Exotic plants: It is not all bad

Throughout my final year, I had the opportunity to examine a exotic butterfly host plant species, Aristolochia tagala, as part of my FYP. As I dug up literature on this specific host plant species, I came across an interesting tidbit, the common birdwing (which is the only native butterfly species listed under Appendix II of CITES and is listed as vulnerable under the Singapore Red Data Book) relies entirely on A. tagala as its only host plant in Singapore. The only known native species of Aristolochia in Singapore is Aristolochia jackii, which is locally extinct. It is hypothesized that the local common birdwing population survived due to the switch from A. jackii to A. tagala. Therefore, the conservation and survival of the common birdwing population here in Singapore is heavily dependent on the cultivation of an exotic host plant species.

The planting A.tagala in forested areas to support the birdwing population may not be an option to conserve the common birdwing population. NParks actively removes exotic species from forested areas in Singapore and discourage the planting of exotics near forested areas. Therefore, A. tagala is almost exclusively found in cultivated green spaces. This may not be ideal as the common birdwing is a forest adapted species. This provide a conservation dilemma for decision makers which they have to balance not actively introducing an exotic host plant species into forested areas and the conservation of a common birdwing in Singapore.

A possible strategy that could implement is the reintroduction of A. jackii back into Singapore using individuals from other countries. This may allow more extensive planting throughout Singapore. However, using individuals from other countries may have complications due to genetic differences between sub-species that was in Singapore and other countries. In addition, it is uncertain whether the common birdwing will actively switch back to its native host plant species.

In my opinion, exotic plants often have a negative association with biodiversity, which many people view exotics as harmful and detrimental to native biodiversity. In many cases, that might be true. However, this is a good example which the introduction of an exotic ornamental plant species may have prevented the local extinction of a native butterfly species.



Davison, G. W., Ng, P. K., & Ho, H. C. (2008). The Singapore red data book: Threatened plants & animals of Singapore. Nature Society.

Jain, A. (2016). Ecology and conservation of butterflies in a transformed tropical landscape (Doctoral dissertation).

National Parks Board. (2014) Invasive Alien Species. Retrieved from (accessed 7 April 2019).

Tan, H., & Khew, S. K. (2012). Caterpillars of Singapore’s Butterflies. National Parks Board.

Sprout 2019

As I was doing my research for our Urban Ecology Group Projects, I came across an event, which I would like to share. As our projects this year focus on urban farming, I would like to spread the word about this upcoming event, known as “Sprout”

Sprout made its debut last year on 07 July as Singapore’s inaugural farmer’s market. This year, it is back again on 11 and 12 May 2019 at Suntec Singapore Convention Centre.

This event allows the public to learn more about urban farming in Singapore, and provides local farmers with a platform to showcase local produce and sustainable agricultural practices. During this event, the public will also be able to buy local produce directly from these farmers as well as learn how to farm in their own backyard (or community gardens).

This year, there are over 70 local exhibitors, such as local farmers and those specializing in urban farming. One local exhibitor for urban farming is “Comcrop Rooftop Produce” which employs the disabled and elderly for the seeding, harvesting, and packing of local produce. I would certainly support a company that not only gives such members of our society a chance at employment but also produces local produce. If you are unable to visit Comcrop Rooftop Produce during the Sprout event, fret not, as their local produce can also be found in local supermarkets such as RedMart.

Currently, Singapore imports over 90% of its food supply. That makes us very vulnerable in terms of food security, as we are very susceptible to changes in global food production and supply, especially with the threat of climate change affecting food yields worldwide. To counter this, the Singapore Food Agency (SFA) has recently set a target that 30% of our food supply should be produced locally by 2030. The foods targeted by SFA are locally produced fruits, vegetables, and proteins. To hit this target, there needs to be a greater awareness and support for local produce in Singapore.

Due to Singapore’s urban landscape, most members of the public are unaware that there is local farming happening right here on our tiny island. In my opinion, this event provides a wonderful opportunity for members of the public to try local produce, meet the farmers behind urban farming and learn more about urban farming in Singapore.

It is also a great initiative that can help to raise awareness about local produce, and encourage its consumption. This could, in turn, help to raise the demand and supply of local produce, and we might even be able to hit SFA’s target by 2030, but more importantly, it will also ensure Singapore’s food security in the long run.

I would encourage everyone to go, as well as spread the word about Sprout. This event happens after the exam period and admission is free! In fact, if you register to receive updates about Sprout, you have the chance to win a free goodie bag!

I hope there will more such events in the future and growing support for local produce.



Mahmud, A. H. (2019, March 07). Singapore aims to produce 30% of its nutritional needs by 2030, up from less than 10%. Retrieved from


Sustainable Singapore: Dream vs Reality

The city-state of Singapore is often portrayed as a utopia in terms of quality of life, economy, and sustainability. In fact, the Sustainable Cities Index 2016 ranked it first in Asia and second globally. On paper, the Sustainable Singapore Blueprint looks ideal. But environmental utopian models such as ‘eco-cities’ have poor track records when it comes to implementation. My question is: has Singapore managed to turn these environmental dreams into reality?

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Improving NParks’ Nature Ways

I conducted a research project on the biodiversity of NParks’ Nature Ways (NWs) for several months last year. A relatively new undertaking, NWs are stretches alongside roads planted with selected tree and shrub species that aim to “facilitate the movement of animals like birds and butterflies between two green spaces”. They are strategically located to 1) link biodiversity-rich areas to urban communities, 2) serve as wildlife habitats and 3) increase residents’ accessibility to nature. These green corridors beautify our immediate surroundings and are designed to inculcate greater appreciation of Singapore’s abundant (read: remaining) biodiversity.

These short routes may seem unlikely havens, given their locations — sometimes beside major four-lane roads — that are highly disturbed by both vehicular and foot traffic, besides regular maintenance by NParks’ stuff such as pruning (a necessity to prevent shrubs from becoming overgrown and thus inciting negative public feedback). However, over the course of several months, I was pleasantly surprised to come across several common and not-so-common butterfly and bird species, including the striking Tailed Jay (below, left). While relatively common, this species frequents treetops and is rarely spotted at ground level; presumably, it was attracted to the flowers of the nearby Ixora. I also recorded one sighting of the “Moderately Rare” (Khoon, 2010) King Crow (below, right).



Some photos of my other personal favourites are in the collage below. From top to bottom, in the left column: Leopard Lacewing, Blue Glassy Tiger, Peacock Pansy; right column: Brown shrike, Common flameback, and Yellow-vented bulbul.



While these sightings indicate that certain species do utilise the NWs for forage and shelter, these are largely limited to the common ones, generalists with a wide range of suitable caterpillar host plants or food sources.

I believe that this is one way the NWs can be improved upon. Instead of further expanding the already extensive habitat of the generalist species, more focus could be placed on enhancing these locations to increase their suitability as habitat for other species — for instance, by planting a greater selection of host plants, as was done to great success at the Alexandra Hospital butterfly trail in the past.

This is also a good opportunity to introduce a new citizen science programme centred on the enhancement of biodiversity on NWs. This could be targeted at nearby residents, who will directly benefit from improvements made to these areas, and for whom the volunteering programme would be relatively accessible. It would entail the provision of caterpillars of less-common species (bred from local stock where possible) to the volunteers, who would rear and release them upon eclosion. Leaves of the host plants could be obtained from the NWs to feed the caterpillars. To maximise resident involvement, a poll could be conducted before the commencement of the project allowing residents to vote for their preferred species to care for. This being a child-friendly project, it would also help cultivate interest and curiosity for nature in the young, which is an important step towards a nation of like-minded people who care for the environment.



Khoon, S. K. (2010). A field guide to the butterflies of Singapore. Singapore: Ink On Paper Communications Pte. Ltd.

Roadkills in Singapore—one too many?

As we all know, the fragmentation of natural habitats is one of the many repercussions brought about by urbanisation. Roads especially, have both positive and negative impacts, the latter being the increased likelihoods of roadkill and the former being increased connectivity.

While the benefits for us are clear, there has yet to be any significant benefits for wildlife in general (Fahrig & Rytwinski, 2009).

Singapore is known for its extensive green cover, where even the roads and highways are lined with trees and shrubs. Although this helps to ameliorate the impacts of the Urban Heat Island (UHI) effect, it might inadvertently attract more animals to the vicinity, increasing the chances of roadkill; with the ubiquity of street lights in Singapore further exacerbating the issue.

Roadkills in Mandai

Sunda pangolin (Photo by: Author)

The recent reports of roadkills (a Leopard cat, Sunda pangolin and Sambar deer) showed a worrying trend [Animals affected by Mandai park works: Wildlife groups; March 24, 2018]. Mammals are uncommon in Singapore, with small mammals making up the majority of the population. It does not help that smaller vertebrates—which are already threatened by habitat loss and fragmentation—were found to be at greater risk of roadkill (Rodríguez-Castro et al., 2017).

Proposed eco-link bridge (Photo by: Mandai Park Holdings)

It was heartening to know that in addition to the proposed eco-link bridge, several other structures (e.g. green acoustic wall barriers) that protect and facilitate the movement of wildlife would be built, including the retention of existing culverts (MPH, 2016). However, current mitigation measures—like road signs and speed bumps—are still inadequate as wildlife in the vicinity have no structures to aid their movement across the temporary fauna crossing, rendering them vulnerable to vehicular strikes.

Traffic calming measures. (Photo by Mandai Park Holdings)

Apart from mammals, birds should be taken into consideration during the implementation of mitigation measures as well. Despite (most birds) having the ability to fly, some birds are territorial and rely on their songs to find potential mates, thus noise pollution would affect their hearing, forcing them to go closer to roads. Light pollution from street lights and vehicles pose threats too, as migratory birds often rely on starlight for navigation, hence rendering them vulnerable to collisions (Glista et al., 2009).

Animals in the vicinity are already facing significant levels of stress from the construction works and shepherding; ergo, relevant authorities should not be complacent, and look into enhancing roadkill mitigation measures by consulting nature groups for further improvements. Emulating its predecessor (Eco-Link @ BKE) should be a given, but there are definitely areas that could still be improved upon. Beneficial design elements from other wildlife crossings, like the Sungai Yu wildlife corridor and Banff National Park, should be taken into consideration for incorporation into Mandai, as well as future projects.

If we truly wish to bask in the beauty of nature and reap its benefits, the onus is on us to retain, or better yet, enhance the connectivity in our highly disturbed environment, with inconveniences borne by us and not the wildlife.

Sungai Yu Eco-viaduct (Photo by: MYCAT)

Towards a “car-lite” society

On the other hand, the suggestion to designate Mandai Lake Road as a ‘car-lite’ zone is a feasible one and should be taken into consideration [Make Mandai vehicle-light to reduce roadkill; Mar 29, 2018]. After all, Singapore is in the process of shifting to a ‘car-lite’ society, and has in fact designated some areas of the upcoming Tengah estate to be ‘car-free’ [New Tengah HDB town heavy on greenery, light on cars; Sep 9, 2016]. The Jurong Lake District has also been designated as a ‘car-lite’ area as well [Fewer car parks, more cycling paths in Jurong Lake District; Aug 25, 2017]. With a car-lite society, roadkills would hopefully be reduced, if not kept to a minimum.

Another suggestion would be abolishment of the car park in the East Arrival Node, which is situated near the Central Catchment area (MPH, 2016). Having a single carpark outside of the sensitive Central Catchment area, with designated buses shuttling visitors in and out of the wildlife park would significantly reduce traffic along Mandai Lake Road, and hopefully, roadkill incidents too.

Roadkills, regardless of the conservation status of the animal, are detrimental to Singapore’s sensitive ecosystems. For this reason, I implore Mandai Park Holdings (MPH), the parent company behind Wildlife Reserves Singapore (WRS), to make roadkill statistics available to nature organisations and institutions, so that they can analyse the data and provide constructive feedback. In highly urbanised Singapore, incidents of roadkill are bound to occur, even with robust mitigation measures. I hope that authorities can learn from the mistakes of Mandai, and put more measures in place for the upcoming Tengah estate, in order to best preserve what precious little wildlife Singapore has left.



Fahrig, L. & Rytwinski T. (2009). Effects of roads on animal abundance: an empirical review and synthesis. Ecology and Society 14(1): 21. Retrieved from:

Glista, D. J., DeVault, T. L., & DeWoody, J. A. (2009). A review of mitigation measures for reducing wildlife mortality on roadways. Landscape and Urban Planning.

Mandai Park Holdings [MPH]. (2016). Environmental Impact Assessment (EIA) report. Mandai Park Holdings. Available at: (Accessed 14 April 2018).

Rodríguez-Castro, K. G., Ciocheti, G., Ribeiro, J. W., Ribeiro, M. C., & Galetti, P. M. (2017). Using DNA barcode to relate landscape attributes to small vertebrate roadkill. Biodiversity and Conservation, 26(5), 1161–1178.


Golf Courses in Singapore: What’s next?

Golf courses can increase property values and contribute to economic growth. They also attract wealthy tourists and are recognised as useful sites for business deals. The vast green spaces and well-maintained turf can be aesthetically appealing to some people and provide recreation.

With over 1,500 hectares (approximately 2%) of Singapore’s land area covered by 17 golf courses, there are concerns that they are taking up too much space and are environmentally unsustainable. In this article, I address these concerns and Singapore’s plans.

The New Tanjong golf course at Sentosa. Photo by Amelia Lim.

Environmental impacts of golf courses

Golf course management involves the use of pesticides and fertilisers, which can contaminate the environment (including water bodies), although mitigation measures are already in place. The use of pesticides and fertilisers is controlled and regulated by Public Utilities Board (PUB), and products are limited to a list of approved chemicals. But golf courses are also heavily irrigated. Even though this water comes from water bodies that collect rainwater, and water recycling is widely practiced, it takes a lot of energy to water the turf, in addition to what’s required for overall maintenance of the golf course (e.g., machinery).

Golf courses can also support biodiversity because they are home to species that are adapted to fragmented tree patches and open areas. In some instances, they can even enhance biodiversity, like in Tanah Merah Country Club, where planted, exotic vegetation attracts birds, such as red jungle fowl and herons. But that typically only happens in golf courses built on barren, reclaimed land. For golf courses built on non-reclaimed lands, the disturbance to the natural habitat can be extensive.

Although golf courses inevitably have detrimental impacts on the environment, the sustainability of their practices are improving with time.


So, what’s next

Based on the Ministry of National Development’s Land Use Plan released in 2013, over 200 hectares of golf courses will be freed up for other uses. Two golf courses (Jurong Country Club and Raffles Country Club) must vacate their premises by August 2017 and July 2018, respectively. There will be no new lease offered to some others, including Marina Bay Golf Course, Keppel Club, and Champions Public Golf Course. This is a welcome change, especially given that the 1999 Land Use Plan included up to 29 new golf courses. It seems that the government recognises the concern that golf courses take up too much space, especially considering that less than 1 % of the population plays golf.

However, do fewer golf courses mean more housing development? According to the 2013 Land Use Plan, land allocated to parks and nature reserves will increase from 5,700 hectares in 2010 to 7,250 hectares in 2030. Furthermore, the projected increase will mainly come from urban parks in housing estates. This may seem promising because residents use urban parks more than golf courses. But do urban parks hold higher ecological value? This warrants further studies on comparing the ecological values between urban parks and golf courses. While the death of some golf courses frees up land for development and more parks, it is important to note that quality, not quantity, of green spaces matters.



Soh A (2014) 200 ha of golf course land freed. The Business Times.

Colding J & Folke C (2009) The role of golf courses in biodiversity conservation and ecosystem management. Ecosystems, 12: 191−206.

Heng J (2017) Fewer golf greens, but more greenery from parks and trails. The Straits Times.

Ministry of National Development (2013) A high quality living environment for all Singaporeans. Land use plan to support Singapore’s future population. Ministry of National Development.

Neo H (2001) Sustaining the unsustainable? Golf in urban Singapore. The International Journal of Sustainable Development & World Ecology. 8(3): 191−202.

Neo H (2010) Unpacking the Postpolitics of Golf Course Provision in Singapore. Journal of Sport and Social Issues, 34(3): 272−287.