By Kaeden Sim
On 22nd March, the Bird Society of Singapore conducted our second ever guided Sentosa birdwatching session. This was made possible through our valued collaboration with Sentosa Development Corporation. Throughout the walk, we shared the significance of eBird and its contributions to citizen science by introducing numerous key eBirding practices and demonstrated how careful documentation creates meaningful scientific data. The walk proved fruitful, with 42 species of birds recorded onto our shared eBird checklist!
Our journey started along the Imbiah nature trail where we traversed along the artificial boardwalk cutting through the island’s secondary forests. Here we encountered Red-whiskered Bulbuls and many Blue-throated Bee-eaters. Further down the path, we encountered Dollarbirds utilising the cable car wires as hawking perches. At the summit of Imbiah Hill, we were treated to a brief yet striking fly-by of a majestic Crested Goshawk.
At this point of the walk, we had a few “heard-only” species, namely Common Tailorbird and Lineated Barbet. This underscored an important eBirding practice of not just logging visually confirmed species and photographed birds, but also those confidently identified by their vocalisations.
Afterwards, we made our way towards Fort Siloso. Here we found a tree teeming with Blue-tailed Bee-eaters, a Japanese Sparrowhawk overhead, and a vibrant male Yellow-rumped Flycatcher. Logging sightings of such migrants on eBird allows us to determine migratory trends.
The highlight at this site was definitely the ernesti subspecies Peregrine Falcon soaring overhead, a resident subspecies that has been recently documented to breed in Singapore. More information on this remarkable discovery can be found in this article. eBird records of rare residents can also provide clues on whether the species may potentially be breeding locally.
En route to our final destination, we stumbled upon a puzzling bird perched atop a construction hoarding. After some deliberation we realised it was a non-native magpie (Pica sp.)! This unusual sighting provided us the opportunity to share eBird’s function of categorising species into naturalised, exotic and native groups.
Finally, we arrived at our most anticipated site of the morning, the only known nesting site for Singapore’s Aerodramus swiftlets. This presented a truly novel birding experience for everyone. Few would have imagined needing to navigate through a narrow, pitch-dark bunker to find a bird!
Inside, we learned how to identify the swiftlets from their nests as well as observed “hybrid” nests which exhibited characteristics of both swiftlet species. You can find out more about swift and swiftlet identification in this article. To ensure minimal disturbance to the birds, we only used red light while observing them and our time spent inside was limited to under 15 minutes. In the end, we managed to successfully observe several chicks of the Black-nest Swiftlet and a single Edible-nest Swiftlet chick.
Thanks to all those who participated in the walk and we hope that you’re now armed with new knowledge on eBirding and citizen science, as well as some very cool swiftlet ecology (and also two lifers)! We’re also very grateful to Sentosa Development Corporation for the continued collaboration.
See you all at our next event!