This is personally one of the field trips that I really looked forward to, as I first heard about Kranji Mudflats and the horseshoe crab surveys that has been done there from none other than our guide that day – Lester Tan.

We gathered for a quick intro and briefing about the importance and role of Kranji Mudflat and the main star of our presence that day, the horseshoe crabs.

Kranji Mudflat

Mudflat is a stage just before the formation of mangroves (it’s the crib of an upcoming mangrove). Mudflat is formed when silt and sand from estuaries flow out to be deposited left and right.

Lester asked us: Apart from squishy muddy soft, what’s the texture of the material here? (we did not know). Crunchy. Not that we tried biting or tasting, but the crunch comes from when dead mussel shells are stepped on.

On this note, he introduced about the issue of invasive mussels. The only native mussels in Singapore are the green mussels. As for the Zebra mussels, they are invasive and has already established and stabilised themselves around Singapore and found pockets of places where they prefer. This is an issue because they hinder the lifestyle and survival of horseshoe crabs. More on this later.

Lester also emphasised that as biodiversity friends, the word of choice when referring to nature areas such as mudflats are very important, as they paint a subconscious impression to the listener. Instead of using descriptors such as smelly, dirty, muddy, boring and ugly, we can get creative and use more positive descriptions (shall leave it to us all to explore our creativity).

Kranji Mudflat is the largest area for breeding ground for mangrove horseshoe crab in Singapore. It stretches all the way from Sungei Buloh (West) to JB Checkpoint (East “Mandai”).

Types of Horseshoe Crabs

Contrary to popular believe, horseshoe crabs are not crabs, but more related to insects/spiders/scorpions than crustaceans. It is because of this that a government policy to protect them because far more complex to formulate (to a layman it may sound like, do we need to protect all insects too?)

There are four types of Horseshoe Crabs aroudn the world:

• American/Atlantic Horseshoe Crab
  Gigantic and huge, they have blue blood

• Chinese Horseshoe Crab
  Smaller than Atlantic Horseshoe crab, but still big in size.

• Tri-spine / Coastal / Pacific / Indian Horseshoe Crab
  They have spikes on their tail and their body can grow up to the size of a person’s face. Can be found in Japan, Brunei, Sabah and open water around southern Indonesia.

• Mangrove Horseshoe Crab
  Smallest among the 4, growing up to only palm size. They are found around Asia, up to even India.
  They are technically poisonous to consume due to deadly neurotoxin within, but some still will try to eat them, especially females that carries eggs. They have rounded tail which feels smooth and have much shorter/almost nonexistent spikes as compared to Tri-spine Horseshoe Crab.

Horseshoe Crab Anatomy (for layman)

Their mouth is attached to their legs, so they chew and grind their food as they walk. They feed on worms and basically anything on the mudflat and are bottom feeders. They have more than 2 eyes (uhmmm this tickles my arachnophobia): 2 feeding pairs at the bottom to locate food and up to 10 eyes (note: not pairs) that are sensory to determine tide level, time of the day and the moon brightness.

Horseshoe crabs are not venomous and their tails are NOT used for defensive purposes. Their tails exists so they can flip themselves upright and are crucial to their survival.

Fun fact: Horseshoe crabs can swim upside down. They also have boot gills to help them breathe outside water during low tide.

Challenges faced in Singapore

• Habitat Destruction: need I say more?
• Land Reclamation: the ultimate killer of most shore and reef biodiversity.

Survey guide:

To differentiate gender, look underneath. Females have uniform legs that are pretty and slim. Females are also usually way larger than males. Males have two bulging arms. Anything with a pit-to-pit measurement of 7.5cm and below are considered juvenile. During mating season, Male HSC will latch onto Female HSC using their 2 forearms. Males don’t eat while mating while females will continue to walk around to eat.Sometimes, multiple males will go for 1 female, and all will latch onto each other until the female decides to dig a hole to lay eggs. The first male right behind the female will fertilise the eggs.

HSC Predators are less studied. The list below are general understanding at this point:

• Atlantic HSC: sea turtles red knots (shorebirds) – they are high protein to the predators
• Mangrove HSC: not sure who eats them, crab eating macaques, crocodiles, storks and otters. Otters sometimes play and kill but don’t really eat them.

The good thing today is that, after being highlighted by the scientific community, horseshoe crabs have been given an IUCN status, whereby with a IUCN status, it’ll be easier for government and relevant parties to push for conversations and policy making.

IUCN status:
Mangrove: vulnerable
Coastal: endangered

Other than that, there are currently still no laws that protects horseshoe crabs from being harvested or poached from the wild.

Two friends of over 15 years wanted to meet once last time before one of us enters her married life. We decided to change up our usual meet ups at cafes and indoor spaces as we want to explore more parts of Singapore. It’s a decision I highly supported!

On the actual day, 10 July, we narrowly avoided the morning showers as we almost decided to go in the morning. We took a nice 10-min walk from Marsiling MRT to Blk 134 before reaching the Woodlands Town Park East. Weather was great and sunny, heng ah!

We first got to know about this park from MothershipOnEarth instagram post. There is a small portion of this park that has been initiated, created and maintained by this pair of father and son over 2020 when the pandemic first hit our nation. The park features a variety of ornamental plants with flowers that attracts many kinds of pollinators such as bees, butterflies and other insects.

As it was all of our first time visiting this park, I had no clue what flora and fauna can be found there.

The park sits at the base of a small hill. We entered from the other side of the hill, so there was this section of big steps to climb, slightly similar to the park in Bukit Batok. Upon reaching the top, we paused to admire the scenery around and started envying the residents around.

Thereafter, we spotted our first fauna friend of the day: Scarlet-backed Flowerpecker. I brought my binoculars and started looking at it, but could not get a picture before it flew away. What.a bummer! We started walking around the top before proceeding down the tiered steps to the actual ornamental flowers park.

Along the designated paths, I introduced about a few plant types that we see along the way: Simpoh Air, the symbiotic relationship of ants, aphids and Macaranga tree, Chempedak, Indian Snakeweed and many more common garden sightings.

It wasn’t a very tough walk, just enough to make you feel fit once you reached the top. We took a walk around the top and walked downhill, The path downhill was filled with flowering shrubs and many butterflies were weaving amongst them.

Then, pause!

A flock of four Asian Glossy Starlings flew into our sight and stopped a few feet down the path that we were on. It was a good opportunity to introduce my 8×42 binoculars to my friends, how to use it and how much details they are able to see when they birdwatch with a pair of binoculars. They experienced the common challenge of focusing, looking through two eyeholes and locking in on their target.

Apart from camps at Pulau Ubin, I have never done a night walk in nature areas in Singapore due to the 7-7 opening hours.

Our guide, Uncle Tony, is an expert with trees. He shared that the highlight of our trip would probably be spotting the big three of BBNP: Malayan Colugo, Palm Civet Cat and Flying Squirrel — almost a guaranteed sighting. Read on to find out if/when these hosts showed their face!

We started the walk right at the carpark area. Uncle Tony started introducing almost tree after tree, plant after plant from the carpark to start of the path. Here are some that we saw that night:

1. Sea Apple – there are 36 species!
   A question that Tony prompted us was: Why would a Sea Apple tree be found so deep in mainland? Singapore’s small land has a part in this question, but more so of the history of how it was brought in.
   In late 1800s, Teochews wiped out forests for their Gambier plantation. 15 years later, the land was overgrown with lalangs, both plants that grow well on poor soil. As these plants acts almost like tinder to starting a forest fire, this area became prone to forest fire due to the high likelihood of lightning strikes. As a method of mitigation, Sea Apple was planted as a fire breaker, to shade the ground below, hence reducing lalang growth.
2. Simpoh Air
   This is a common shrub that are found at many parks around Singapore. It produces fruit that has a lot of little seeds which attracts birds. It is an important food plant for the ecosystem.
3. Figs – there are 30+ types of figs in Singapore. (We were looking at ficus glossuroles)
   Figs are important because they flower and fruit at different times throughout the year. They are a good food source for fauna in an ecosystem. Another example of a common but not low class plant.
4. Rubber Tree
   A common tree in my workplace at Pulau Ubin – this tree has seed pods with cool seeds. They can be easily identified by how their leaves always grow in sets of threes.
5. Singapore Rhododendron
   The leaves of this plant have characteristic 3 veins.. The leaves are crushed to be applied over injuries during the kampung days. Kampung knowledge of plants and their medicinal values are often passed down from the matrimonial side.
6. Birds Nest Fern
   The overhanging dead leaves and root materials provides a great roosting site for fruit bats. Will be sure to observe bird nest ferns more closely after knowing this!
7. Rain Tree (non-native)
   Rain Trees are from the United States, but somehow flourish and grow well in Singapore. It can provide shelter and home for many kind of birds,
8. Wild Orchid (ok we weren’t able to ID the specific name)
   Orchids need a specific amount of shade to thrive.
9. Ten Men Tree
   Characteristic ripped apart bark due to the diameter growth of tree trunk. It has a fluted buttress and can grow really tall

While Uncle Tony was introducing about these trees and plants to us, we were also on the lookout for the big three. We spotted fresh Palm Civet poop, but did not see the pooper around. Other than a chicken roosting on the tree (cannot determine if it’s domestic chicken or jungle fowl due to poor lighting), we did NOT see any of the big threes. What a bummer, as some of us has never seen any of the big threes before.

Uncle Tony was also surprised that none showed up today, and since then, our group became THE group which didn’t spotted any of the big threes among subsequent BBNP night walks. :’)

Here’s the little plot twist after the walk:
I waited for my bus after we parted ways, but missed 2-3 as it was getting really late and drivers drove past that ulu (deserted) bus stop really fast, assuming no passengers wants to board. I eventually decided to try my luck at a different bus stop which has a higher likelihood of stopping the driver in time and had more bus numbers that went my way. On the way to that bus stop, I noticed something rustling in the grass patch beside me. Turns out it was a hungry Palm Civet looking for food! It froze when it saw me, and very dramatically moved into the dense vegetation in a slow-mo manner. That lifted my spirits completely!

While waiting for my bus at the next bus stop, I was looking hard at the bright car lights to spot the numbers I need. All of a sudden, a squarish shadow swooped from the dense vegetation of BBNP onto a lone tree planted between the roads. It then started climbing upwards and went too far for my naked eyes to see. That makes it 2/3 for me that night! I was beyond delighted by the surprise presence.

This field trip was personally really memorable because of the sightings at the end after we parted ways. Also, a big thank you to Uncle Tony as the things that he shared were eye opening, My favourite takeaway line from him during this walk would definitely be:

A common plant doesn’t mean it’s a low class plant.

Uncle Tony

Disclaimer: No nat-geo quality photos in this post, and not all that we saw were captured in photos either :’)

Singapore’s Bishan-Ang Mo Kio Park used to be a concrete canal just like many other existing ones around the island. However, efforts have been put in to revitalise and turn this place into a bioswale. According to NATCO.org, Bioswale is a vegetated, shallow, landscaped depression designed to capture, treat and infiltrate stormwater runoff as it moves downstream. In other words, everything is naturalised. Flooding helps to create an environment that offers different types of habitat for biodiversity. Compared to the common concrete canals, B-AMKP is an excellent example of adaptation of a city while taking nature into consideration — establishing an ecosystem while solving the original surface runoff problem. Despite hearing much about this park, I have only passed by it on the way to a friend’s house

To kickstart the day, I arrived at the gathering point to find out that the group chanced upon a White Throated Kingfisher. I missed it though! But that was fine, as more birds awaited.

Subsequently, we saw our most common resident: Javan Mynah. Javan Mynahs are native to Java and Bali, Indonesia, but established its population in Singapore possibly as a result of escaped pet trade, They are non-native to Singapore. However, unlike the buay paiseh (unapologetic and daring) Javan Mynahs in Singapore, the Javan Mynahs in Java and Bali are actually skittish and will not let you come close at all!

We also spotted a female Brown-Throated Sunbird, with distinctive yellow eye-ring that differentiates it from female Olive-Backed Sunbird. The latter has a yellow brow and some white on their tail edges. We learnt that they are a victim of the Violet Cuckoo (quite trendy among bird groups at the time of this field trip). Violet Cuckoos will lay eggs in unknowing sunbird’s nest and sneakily let the sunbirds raise their offspring. Only when these intruder chicks grow up, will the sunbirds realise the situation… The issue with this is the risk of parent sunbirds being worn out from constantly finding food to feed the chick which has obviously bigger appetite than a regular sunbird chick.

Along the bioswale, we saw a Purple Heron perching at the canopy of a tree. Can’t help but wonder if he was spying on the residents nearby.

As we walked further, we saw a few parakeets squawking once in a while. We heard the calls of Blue-Crowned Hanging Parrot as well, which I unfortunately did not get to see using my binoculars.

We spotted a few Malaysian Pied Fantails, but the highlight of the day has got to be witnessing a pair of MPFs interacting with a female Asian Koel. We had no idea what they were doing, but the Asian Koel looked harassed by the much smaller sized fantails.

Another memorable spot was juvenile Pacific Swallows. Although they fly almost as fast as the adults, juvenile Pacific Swallows carry this young, baby vibe that makes them look adorable.

Finally, the greatest takeaway was learning from Nasry about these two terms: Precocial and Altricial birds.

Precocial birds are those who hatched from an egg with feathers ready, such as fluffy ducklings, ostrich, emus and chickens. They also don’t have gapes.

Altricial birds are those who hatch naked with no feathers but pinkish wrinkly skin. These chicks have gape as that allows parent birds to know where to feed.

That was a really interesting information as I have never explored or thought about this. Thanks Nasry!

Overall, I was slightly disappointed that I did not spot many new birds (eg. owls), but I am thankful that we still had some bizarre sights like five squirrels hanging out on the same branch the fantail-koel drama. Rest of the time during this walk was spent appreciating the beautiful park.

Nature walks like these are enjoyable, and I do look forward to exploring more local birding spots on my own.

Thank you facilitators!