City of garden and water (城市里的花园和水) 

The natural ecology of Bishan Park -碧山公园-自然生态

Why A Naturalized River brings in Biodiversity？为什么自然溪流带来多样性生物 ？

Moving from the old concrete canal to a newly naturalized river, new habitats are created. Long grasslands and a new waterway attract a wide variety of birds and insects. A whole new ecosystem has been created. Many species of wildflowers have self-sowned along the banks and attract a whole range of other biodiversity. ABC waterways project (Kallang River Bishan Park) aims to introduce a more natural system in urban areas so that residents and visitors can enjoy new leisure activities. They can get to get close to nature, and learn how to co-exist together in a shared green space.

Purpose of Wild flowers in Bishan 

Along either side of the river bank, many water loving wildflowers have taken root and established themselves in this unique environment. Wildflowers give the landscape a new variation of color and texture, something unique to bishan park. There are a wide variety of wildfowers that not only gives us aesthetically beautiful and charming flowers, they also provide seeds and fruits for the birds to feed on.

Wildflowers with Edible Fruits 野花与食用水果

Wild Maracuja or Stinking Passion flower

Wild Maracuja is a creeper that has thin and wiry stems. When the leaves are crushed, it gives off an odour that is unpleasant to come people, thus being called ‘stinking passion flower’ in some countries.

Commonly found in kampongs back in the old days. The flowers of the wild maracuja are unique and beautiful. Edible sweet yellowish-orange fruits with black seeds that are encapsulated within a feathery wrap. The fruits are also keys sources of food to the birds and  small mammels.

Bladder Cherry 膀胱樱桃

Balloon-like structures are formed by the sepals (the outermost layer of a flower). Small, yellow, juicy berries develop within the balloons and are rich in Vitamin C. The berries can be found in local supermarkets and are often preserved in sugar and used for decoration on cakes. This species has very good resistance to insect pests and diseases.

野菜  Edible Herbs

Basil  蓬蒿

This herb is popular in Thai cuisine and is good for tomato dishes. It is also used to make pesto for pasta. Inhaling the vapours of sweet basil tea is thought to reduce fever. The leaves are used to relieve excess gas and treat coughs. Thai basil is also considered to be an auspicious plant for prayers in some religions. Here in Bishan Park, two kinds of basil can be found.  Sweet basil (green stemmed) and Thai basil (purple stemmed) can often be found along the river banks.

Red Sessil  紫红色的叶子

Dark reddish purple leaves provide colour contrast in mostly green landscapes. This cultivar is planted as a border or groundcover. Ideal for damp soils or humid environments, such as pond edges or terrariums. Tea prepared from the leaves is thought to improve blood circulation and reduce high blood sugar and cholesterol. The leaves may be consumed as a vegetable.

WildFlowers  野花系列 

Stylo Townsville 柱花草汤斯

Tolerant of saline soils and soils contaminated with heavy metals. Can be used as a groundcover that helps to reduce soil erosion. Planted to improve nutrient poor soils, because it is a nitrogen-fixing legume that adds nitrogen to the soil. In Australia, this species is grown as pasture to feed goats,sheep and cattle and is also used to make hay. Planted as a cover crop to prevent weeds from growing in agricultural fields.

Mexican Petunia  墨西哥矮牵牛

Produces pink or purple, trumpet-shaped flowers that provide nectar for bees and butterflies. Fast growing species that tolerates a wide range of light and soil moisture conditions. Often used in landscaping, because it grows well in many types of environments and has large flowers. Used in phytoremediation to cleanse water by removing excess nutrients, like nitrogen and phosphate.

Kang kong 甘弓

Leaves are rich in iron. They are usually stir-fried and found in popular dishes such as Sambal Kangkong. Consumption of leaf extract helps to reduce blood sugar and may benefit diabetic patients. This species accumulates heavy metals, such as lead, cadmium and mercury and can be used in phytoremediation to cleanse polluted soils. This species tends to grow aggressively. It can choke waterways and is a potential tripping hazard for people.

Red Fox 红狐

The red fox is a tropical plant that is well known for its vivid colors. It is a branching annual with oval leaves that contain a multitude of tiny flowers that are densely packed into beautifully colored flower heads. These are commonly sold at plant nurseries during Chinese New Year and can be used cut or dried.

Water Birds 水禽

With the naturalised river, water birds are more commonly seen nesting and feeding in Bishan Park. 

Purple Heron苍鹭

The purple heron is the most colorful heron at Bishan Park. Its purplish plumage provides the perfect camouflage in the grasses and reeds. They don’t often wade in deep waters, but prefer to stand motionless in shallow waters to wait for fishes and insects to come by. These 1m tall birds are solitary hunters who hunt at night and in the early mornings The purple herons nest in small colonies in dense reed beds and thick vegetation, mostly in the Central Nature Reserve and costal mangroves. They come to Bishan Park to feed in the day. In Bishan Park, there are more than 5 individuals that are always found fishing and circling in the sky. That is a good number for a short 3 km of naturalized river.

Black Crowned Night Heron 黑冠夜鹭 

Black Herons are a rare sight in Bishan but they are becoming more and more commonly seen in the naturalized river. Night Herons do not fit the typical body form of the heron family; they are stocky with shorter bills, legs and neck. They are often seen hunched up at the fringes of the river islands in the midst of the thick vegetation. Their short necks and white plumes erects when greeting other birds and during courtship. They nest in colonies and often in Singapore with other birds like the striated herons or purple herons.  Cool fact: Young night herons often disgorge their stomach contents when disturbed, making it easy to study their diet.

White-breasted Waterhen  白胸水禽   

They are often heard before they are seen. Malays have named them Ruak Ruak after their loud calls. In Bishan Park, they are most often seen running around the hibiscus bushes along the river at the test reach. There is a family of waterhens nesting in the Lotus ponds and you can often see the chicks playing on the lotus leaves. The chicks are fluffy and black. They feed on seeds and insects and have a chicken like pecking movement when scouring the low bushes for food. They are interesting birds to observe.

Little Egret 小白鹭  

Little Egrets are the most common egrets of Singapore. It has a black bill, black legs and yellow feet. Easily spotted along the river waiting for prey or ‘dancing’ around chasing fishes along the banks

Seed Feeding Birds  种子饲养禽鸟 

With the long knee length grasses found along the 3km stretch of river. Wildflowers in bloom often provide a wide variety of seeds and fruits that attracts seed feeding and grass birds. 
Scaly Breasted Munia  鳞屑文鸟

Scaly Breasted Munias are one of the most common munias in Singapore. They can be found in large flocks of more than 50 birds in Bishan Park throughout the whole 3km of waterways. Munias specializes in feeding on grass seeds and sedges and love foraging the tall grasses. Often, the rarely seen black headed and white headed munias can be spotted in the midst of their flocks. They are agile little birds which can be often mistaken for the common Eurasian sparrow from far. The young are playful and can be seen hanging off sideways and upside down on reeds.

Paddyfield Pipit  稻田鹨

A small brown streaked bird with an upright posture seen on short grass areas. Seen foraging seeds and hunting insects on carpet grasses on either banks of the river.

Dragonflies and Damselflies  蜻蜓和豆娘

Common Scarlet  常见猩红

The Common Scarlet is the largest red dragonfly in Singapore and can be found in large numbers along Bishan Park. This species is also the first to colonize the Bishan Park waterways. The males are a deep scarlet red and the females are brownish yellow. On good sunny days, lots of them can be seen flying around the river.

Common Chaser  常见猎蜓

Yellow-tailed Ashy Skimmers can be found in habitats with standing and slow flowing waters. They usually perch in high areas while preying and appear near body of water to mate and lay eggs during bright hot afternoon and disappear after that.

Common Bluetail   常见蓝尾蜓

The Common Bluetail is common in our nature reserves and widespread throughout the country.

This tiny damselfly is the first damselfly to colonise Bishan park. It can be found perched on the

vegetation adjacent to the water

Variable Wisp 变幻精灵

The color of this damselfly changes with maturity. Its colors ranges from white, to pale blue to

orange. It is the smallest species of damselfly in Bishan Park. They are usually found perched on low

Grasses  草

Exotic Species and Why they Harm the Ecosystem

Exotic species reproduce at an alarming rate and will outcompete their native counterparts for food and shelter. Native species of animals are much more vulnerable to alien predators because they have been thriving without the introduced species prior to the latter’s entry into the

habitat. Coupled by a slow reproductive rate that was sufficient to maintain the species, alien

predators can wipe out native species extremely effectively.

Fish 鱼    

Spotted Tilapia  斑点罗非鱼  

The spotted tilapia is one of the most invasive exotic fishes in our waterways. Here in Bishan Park,

the Kallang River is home to a big school of tilapia. The abundance of hiding spaces between the rocks and boulders are ideal for the fish nurseries. A pair of spotted tilapia will bond well in advance before mating and remain together to care for their young. They are reported to be monogamous.

In Singapore, the spotted tilapia has overrun it environment to the point of being highly invasive. These semi-aggressive fishes are usually the dorminant fish in our pond and canal systems and have the potential to affect other introduced native fish Tilapias are an important source of protein in South East Asia. Typically, commercially raised tilapias (red tilapia) can be found in our supermarkets/wet markets.

Mosquito Fish   食蚊鱼

Introduced into ponds and other water bodies, mosquito fishes highly adaptable to their

environments and are small enough to get into small pockets of water and feed on mosquito larvae. They are small and dulled colored, thus not valued for their aesthetic and ornamental value. They reproduce at a rapid rate and are found through small pockets of the Kallang River at Bishan Park. 

American Bullfrog  美国牛蛙 

This is the largest frog in Singapore. However, it is not native. Commercially bred for food (frog leg) and religious offerings, people have been introducing them into our waterways by releasing large numbers during festivals like Vesak day.

American Bullfrogs are highly invasive and has created devastating effects in the ecosystem by outcompeting with fish and other frogs for nesting grounds and food. They eat a great variety of food, which includes anything they can swallow from other frogs, fishes, small birds and even their own kind.  A female bullfrog can lay up to 20,000 eggs each time and have multiple clutches each year in a suitable environment. At this breeding rate, they can easily outcompete out native species. At night you can hear a low baritone moo-ing from the waterways. This is the distinctive call by the bullfrog, hence its name.

Giant Apple Snails  福寿螺

These usually found in aquarium shops. These appear to have yellow shells, but those found in the wild usually have a shell with a more brownish-green coloring due to the algae and food consumed.  They lay their eggs on boulders and leaves above the waterline in bright pink clutches. These eggs are soft and have a milky color when laid, but they harden within hours. They hatches after 2-4 weeks, the baby snails eat their way out and drop into the water. Many fishes like the tilapia eats these small baby snails.  The apple snails not only have gills, they have the ability to bread air in combination with a shell door and can survive periods of droughts by burring themselves in the substrate with their shell firmly closed.  

The naturalized river has provided an ideal habitat for snails to feed on detritus and lay eggs on the side on the vegetated banks, thus, numbers are very large here at Bishan Park and we need to clearthem when the population has exploded. They can grow as large as fist sized.