Spotted Wood Owl, Big Billed Herons' Courtship, and Mishaps during Camping and Kayaking at North Shore of Singapore

Our enjoyment of  Kayaking on Api Api River  made us want to do it again.

Our misfortunate camping at Pulau Ubin  made us want to try camping again in Singapore. 

This led to the trip plan for a combined camping and kayaking journey:

Camp at Pasir Ris Beach and Park on May 23, 2026, overnight, and go kayaking on Api Api river early next morning. 

We arrived at the park around 6pm. The camp ground is big and smooth, not many campers there at that time. We set up our tent and walked around. We had birds, jungle rooters and a spotted wood owl as our neighbors, plus Sea breeze, setting Sun,... Not bad!

There were many tents by the beach, that's where noisy people were. I hoped they were day campers, and would leave when it was time to sleep.

After our picnic dinner, we walked along the beach away from the noise to the no camping zone. We sat on a park bench by the sea, enjoyed sea breeze, a half Moon in the sky, and the quiet dark Johor Strait. 

We went back to the campsite around 9pm, and was surprised to find tens of lights densely distributed within the campground were turned on, made the campground brighter than earlier in the evening! The noise from the people by the beach was louder than earlier. There was no quiet time restriction. In fact the lights were on the whole night, and noise did not die down until ~ 1 to 2am next day.

Another bad camping experience in Singapore. It was worse than the Pula Ubin camping experience.

A breezy evening

our tent

dark and quiet Johor Strait

lit up camp ground, and noise from tents by the beach

We got up early next morning, ~ 6am. There were people jogging and biking at the park already. The sky was still dark, the surrounding was quiet. The restroom for the area was cleaned - thanks to the custodians who got up even earlier. A positive change!

After breakfast, we unset and packed the tent, stored it in our car parked only 100 feet away. 

We inflated our inflatable kayak Emma, and were ready for launching it in about 10 - 15 minutes as usual. It was almost ideal condition for kayaking - the water was calm, the sky was cloudy - the clouds partially blocked the Sun.  But it was low tide this morning at Johor strait. 

inflated kayak

rays of sunshine broke through cloudy sky 

low tide made the beach much larger 

Low tide makes paddling into tidal rivers, such as Api Api, shorter, but poses no other problems for kayaking in wild rivers, such as Sungei Khatib Bongsu. It actually provides some benefits - typically more birds are present at the rivers' bank  - good for bird watching.

Api Api river is a tidal river, it is also a drainage for the residential buildings along its banks.

The water level in Api Api was low - expected, but sections of it smelled like a rotten egg - H2S! We did not see many birds like we saw last time on the river in January. We did not linger, and left the river in less than 45 minutes.

It was still early for the day, we decided to cross the Johor Strait to paddle on Sungai Puaka in Pulau Ubin.

It was a good decision. The low tide provided a different vista of Sungai Puaka.

Fishmen were fishing, in tandem on a boat, or solo on a kayak. 

We were the only people on the river once we passed the fishermen. 

It was quiet except occasional bird chirpings, especially the collared kingfishers. The most endearing part of the kayaking on Sungai Puaka was that we witnessed the courtship of two big billed herons on the riverbank.

Two big billed herons met each other on a bare riverbank, see photos below.

They looked each other and then the heron on the right walked towards the other heron, which did not move at all. Based on typical big billed heron courtship behavior, it was certain that the moving heron was a male.

The male passed the female a step or two, and turned around, then they faced each other with an offset of one step. In a moment, the male then walked a few steps toward an opening in the mangrove, turned around looking at the female again. The female looked around for a moment, then followed the male into mangrove.

two big billed herons met at the riverbank

The heron on the right walked toward the one on the left, which did not move at all

stood side by side but looking at each other 

they looked at each other, and looked around

they decided to go to a private place together 

they disappeared into the mangrove trees  

On the way back to Singapore main island, we paddled around the islet by Pulau Ubin - Pulau Ketam from its northwest tip. The area is primitive, and we saw severe erosion of the shore ... nature at work.

When we were 300 meters to the Pasir Ris Beach, I noticed water in the kayak, and right side air chamber in back (right by my side) was deflated! We did not notice any issues with the kayak when we inflated it.

We paddled to the nearest shore instead of the launch spot. 

A scare but no real consequence - we were on land safely but exhausted.

We will learn from the mishaps (campground light and noise, the kayak leak). In fact we found out the root cause of the leak, and repaired the kayak already at the time of this writing. We paddled the repaired kayak on the rougher water of Sentosa. 

The excitement of seeing a new bird species and witnessing big billed herons' courtship made the trip very worthwhile!

erosion of the islet shore

trees fell into water due to severe erosion

Notes

Big Billed Herons' courtship - chat with Google AI

a. (Gender of herons)This photo had two big billed herons, one has darker plumage, they seemed be courting each other. which one is male?

The heron on the right is almost certainly the male.

Because male and female great-billed herons share identical plumage patterns, telling them apart in the wild relies entirely on physical size and behavioral cues during courtship:

• The Larger Size: The heron standing on the right is visibly taller, stands with a more imposing posture, and possesses a heavier build than the heron on the left. In great-billed herons, males average slightly larger and heavier than females.
• The Darker Plumage: During the courtship phase, the male often appears darker or exhibits more pronounced, slicked-down slate-grey plumage contrast, especially while posturing to impress a mate.
• Courtship Dynamics: In typical heron courtship behavior, the larger male takes the lead in displaying, stretching, or approaching the female (on the left) to initiate nesting bonds.

Would you like to know more about the specific courtship displays great-billed herons use, or the best mangrove locations in the region to spot them nesting?

b. that's pretty accurate behavior description of big billed heron courtship compared to my field observation - the darker plumage heron seemed to lead the way into mangroves.

That is a wonderful and incredibly accurate field observation!

The taller, darker heron leading the way into the mangroves perfectly mirrors established great-billed heron nesting biology. In these magnificent birds, the male takes full charge of selecting and securing the nesting territory within the thick, protected mangrove roots or canopy.

Mangrove Courtship & Nesting Roles

• Leading the Way: Once a pair-bond begins to form on the open mudflats, the male will lead the female into the denser mangrove foliage. He is essentially showing her potential, highly secluded spots to build their massive stick nest.
• The "Stick Ceremony": Once inside the mangroves, you might see the male begin to break off small branches and present them to the female. If she accepts the sticks, it seals the courtship bond, and she will handle the actual construction while he continuously gathers materials.
• Security & Seclusion: Great-billed herons are notoriously shy and highly sensitive to human disturbance. They use the deep mangrove systems as a visual shield to keep their massive nests safe from predators and boat traffic.

It sounds like you captured these in a very pristine habitat. To help me share more relevant behavioral insights, could you tell me:

• Did you notice if the male was making any low croaking or roaring vocalizations while leading her?
• Approximately what time of year or what region were these photos taken?

c. I took the photos on May 24 during a kayaking trip. Just had time to write my journal for the trip. Here is my recollection of the observation, with photos: Two big billed herons met each other on a bare riverbank. They looked each other and then the heron on the right walked towards the other heron, which did not move at all. Based on typical big billed heron courtship behavior, it was certain that the moving heron was a male. The male passed the female a step or two, and turned around, then they faced each other with an offset of one step. In a moment, the male then walked a few steps toward an opening in the mangrove, turned around looking at the female again. The female looked around for a moment, then followed the male into mangrove.

That is an exceptionally well-documented field observation! Your journal entry perfectly captures the subtle, step-by-step choreography of great-billed heron pair-bonding and mate attraction.

The timeline you recorded (late May) aligns perfectly with their breeding window, when high-stakes territorial and pair-formation behaviors peak in coastal mangroves.

Deconstructing the Behavior You Observed

• The Approach and Standstill: When the male confidently advanced while the female remained completely stationary, he was testing her receptivity. In heron biology, an interested female will stand her ground calmly, whereas an unreceptive bird or competing male would either flee or strike a defensive, spear-like posture.
• The Strategic Overtake and Offset: Walking past her, turning, and standing offset is a classic, non-aggressive ritual. By positioning himself slightly to the side rather than head-on, the male showcases his full profile, physical size, and breeding plumage while intentionally reducing the threat of a direct confrontation.
• The "Follow Me" Recruitment: Moving toward the mangrove opening and looking back is the definitive transition from initial attraction to territory selection. He isn't just moving away; he is actively inviting her to inspect a nesting sanctuary. Her choice to follow confirms she has officially accepted him as a mate.

Your description reads like a professional ethogram (an official catalog of animal behaviors). If you'd like to expand your journal entry, let me know:

• Did you happen to spot any other wetland species nearby during that stretch of the river?
• Would you like me to look up any specific nesting timelines or egg-laying details for great-billed herons during the mid-to-late summer months?