Raptor Migration (Autumn) along Henderson Waves
Article and photos by Keita Sin
Birdwatching in Singapore gets particularly exciting during the migratory season. One of the groups of birds that migrate through Singapore is what are generally referred to as “raptors” – birds of prey from the order Accipitriformes (eagles, hawks, harriers etc) and Falconiformes (falcon, kestrels etc).
The majority of raptors migrate through Singapore around October to November for the autumn migration, during which they head south to their wintering grounds. During the spring migration in mid-February to mid-April, they will head back north towards their breeding grounds.
There are several locations that have been known to be good spots for raptor watching in autumn. The annual Singapore Bird Group Raptor Count has been conducted at these locations, such as Pulau Ubin, Changi, Tuas and the Southern Ridges (Kent Ridge Park and Telok Blangah Hill Park).
Being a fan of raptors myself, I joined the Raptor Counts at Kent Ridge Park in 2015 and 2016 to watch the convoys of birds flying south-east along the ridge. During these counts, one particular question occurred to me: if the birds were filtering in at different points on the Southern Ridges before continuing to fly along the ridge, wouldn’t it be most productive to do a count as close as possible to its southernmost end?
The birds of Henderson Waves
On 17th November 2016, I made my way towards Mount Faber Park (the southernmost park along the ridge) to find out the answers to my question. However, the views offered there were rather disappointing, and I thus continued towards the Henderson Waves, which offered great views in all directions.
View from Henderson Waves (facing South)
I stood there from 9:20am to 1:00pm and was rewarded with 19 Crested Honey Buzzards; 9 Black Bazas; 1 Booted Eagle; 1 Chinese Sparrowhawk; 8 Japanese Sparrowhawks; and most importantly, 1 Eurasian Sparrowhawk, which then became the second accepted record for Singapore.
Eurasian Sparrowhawk at Henderson Waves, 17 November 2016. Note the 6 “fingers” and bulky body
Observations in 2016 and 2017 by many pairs of eyes led to observations of many other uncommon migratory raptors including the Greater Spotted Eagle, Grey-faced Buzzard, Common Buzzard and Jerdon’s Baza. Other migratory raptors such as the Pied Harrier and Eastern Marsh-harrier were recorded nearby too. Resident raptors such as the Crested Goshawk, Changeable Hawk-eagle, Crested Serpent Eagle and Grey-headed Fish-eagle were also seen regularly (detailed counts in the monthly raptor report).
Left to right, from top row onwards: Jerdon’s Baza, Grey-faced Buzzard, Black Baza, Crested Goshawk, Changeable Hawk-eagle, Chinese Sparrowhawk, Eastern Marsh-harrier, Crested Honey Buzzard, Japanese Sparrowhawk.
Other migrants such as Oriental Pratincoles, Pacific Swifts, Barn and Red-rumped Swallows, Ashy Minivets, and Blue-throated and Blue-tailed Bee-eaters regularly flew over the bridge too.
Oriental Pratincoles at Henderson Waves, 15 November 2017
The highlights, however, were the Asian House Martin (solitary bird on 19 October) and Needletails. The second and fourth White-throated Needletails in Singapore were recorded (a solitary bird on 19 October, and another on 31 October flying together with 2 other unidentified needletails) and another single unidentified Needletail was photographed on 6 November (by Lawrence Cher).
White-throated Needletail at Henderson Waves, 31 October 2017
The diversity of birds recorded at Henderson Waves is astonishing compared to the other sites along the Southern Ridges. It could be that many of the birds flew south through the Central Catchment and only entered the ridge halfway through, causing them to be unrecorded at the other locations. The better view offered at the bridge might also have contributed to the increased diversity observed.
The raptors (and other migrants) usually fly over the bridge from north-west to south-east (from Telok Blangah Hill Park towards Mount Faber Park). The collective observation of the large number of birders stationed at the bridge in 2017 seems to point to a rough trend of having better counts (in terms of both quantity and diversity) when the wind is blowing from the north-west direction.
Birding at Henderson Waves
On text, Henderson Waves sounds like the perfect place in Singapore to go raptor watching. It is, sadly, not as fantastic as it seems. This place offers no shelter from the scorching sun (and yet the hotter it is, the better for raptor migration) and the birds tend to fly very high along the ridge. For those whose main objective is bird photography, Henderson Waves will be a disappointment. However those who are prepared can be rewarded with beautiful sights of convoys of birds, and the occasional low-flying raptor. Those who keep local lists will no doubt be able to tick off a great number of uncommon species.
When birding at Henderson Waves, make sure you protect yourself against the sun – apply sunblock, wear a hat, and put on sunglasses. It will also be great to record the wind direction and share your sightings. A pair of binoculars is a must.
What about spring migration?
Singapore has a lower number (in terms of both quantity and diversity) of raptors recorded during the spring migration. This could be due to the different flight paths taken by the raptors during their return journey, and it would be interesting to find out how Henderson Waves performs then. Could there be a different site in Singapore that hosts the main bulk of raptors flying through in spring? There’s only one way to find out.