Mandai Boardwalk and the many Bulbuls
The Mandai Boardwalk at Mandai Zoo is open to public. Yes, it is free and you do not need to buy zoo tickets). You can enter the boardwalk from either ends of the trail - either from the entrance near River Wonders or the Mandai Wildlife East. There is a shuttle bus to the zoo from Khatib MRT station and some public buses go to Mandai zoo. You can only enter Mandai Boardwalk from 7am to 6pm, and the place will close at 7pm to prevent disturbance to the nocturnal residents.
Note that cycling or any sort of skating, as well as drone-flying, is not allowed. The trail is wheel-chair friendly (I did see a lift at the end of the trail at Mandai Wildlife East)
Straw-headed Bulbul at Mandai Boardwalk
I had many encounters with the Straw-headed Bulbuls within a single visit to this place. It is a critically-endangered species that has somehow been thriving in Mandai Zoo (Probably due to the abundance of fruit trees). Their distinctive calls let you know when they are nearby. They seem to like snacking on this white fruit from a plant that is commonly found along the Mandai boardwalk.
We also encountered a friendly and GIGANTIC pond turtle snacking on the grass.
Wildlife Near Me
You can find interesting nature and wildlife near you with this useful website: https://wildlifenearme.potoo.is
Click the location marker at the top to find wildlife located near your current location more accurately and easily.
Macaques
Well, the macaques also got really close. There are tons of long-tailed macaques snacking on the trees or on the rails. It is wise to not approach them as this species is known for aggression. Definitely do not feed them or display your food or drinks when they are around.
Along the trail, you might get to see (, hear and smell) some of the zoo animals like the macaws and giraffes for free.
The trail is sheltered at many parts too.
Other wildlife you can observe here
Other common wildlife you can see here are the sunbirds, tailorbirds, flycatchers, geckos, red eared sliders, pink neck green pigeons