Rare Horsfield’s Bronze Cuckoo at Tuas, Singapore

Tim and I were blessed to spend nearly half an hour observing and photographing a beautiful and confiding Horsfield’s Bronze Cuckoo, Singapore’s only austral migrant and a rare one at that. In fact, it is considered a vagrant (ie. a bird that strays off its typical migration course because of strong winds, which in this case, has blown it beyond the Indonesian islands towards Singapore). Typically, during the austral winter (ie. May, June, July and August), the Horsfield’s Bronze Cuckoo migrates from Australia to Indonesia. We found it on 14 June 2009 at Tuas Grassland which is located at the western end of Singapore.

Note the clear patch on the belly (broken horizontal lines) of this cuckoo, one of its key identifying features.

We had spent the morning fruitlessly waiting with Jimmy Chew for another target bird to appear, and were about to leave at 11.15am when this cute cuckoo dropped in at our stake-out – a cluster of acacias in the middle of an uneven grassy field. Here, it hunted for caterpillars at close range, never more than 6m from us. At times, it came as close as 2m, always staying near or on the ground, giving us an unparalleled opportunity for some easy camera action with the Canon 100-400mm lens. When it did fly up to a tree to feed, it was never more than 2.5m above our heads (since the tree was not a tall one anyway).

It appeared to prey exclusively on caterpillars and nothing else, catching about 4 to 5 of these juicy larvae in the 25 minutes we spent admiring it. This cuckoo seems to prefer caterpillars as Ashley Ng told me that in the few times that he has observed it, it was also seeking after butterfly wrigglies. Unfortunately, Jimmy had left just 5 minutes earlier. Had I known then that this was a mega rarity, I would have called him back. However, I had misidentified it as a Little Bronze Cuckoo (without checking the guidebooks alas, even after I got home).

The hunting technique of the Horsfield’s is similar to that of other birds, whereby it would angle its head to gaze upwards at the undersides of leaves where caterpillars usually hide, wearing a somewhat quizzical expression and looking most adorable. Upon spotting its prey, it would use its beak to stab-grab the caterpillar, flinging the squirming mass vigorously from side to side to kill it. Then it would swallow its meal whole.

Thankfully Bingwen (aka Albert Low) caught my misidentification after looking at my photos which I had posted on Facebook. Even then, I still confused the Horsfield’s with the Hodgson’s Hawk Cuckoo (seen last December at Bidadari), as both names begin with ‘H’.

So Tim and I had got ourselves a lifer! I then googled around for information and found out just how rare this bird is. According to Lim Kim Seng’s excellent article “Notes on the Identification, Status and Distribution of Horsfield’s Bronze Cuckoo Chrysococcyx basalis in Singapore” published in Singapore Avifauna at http://wildbirdsingapore.nss.org.sg/SINAV_Vol_22_No_7_Jul_08%20.pdf, there are only 10 or so accepted sighting records for Singapore at just 7 locations:

Northwest – Kranji Coast
Northeast – Unnamed location
West – Choa Chu Kang Cemetery
South – Marina City Park
South – Marina East
South – Sentosa Island
East – Changi Beach Park

Funny enough, Ashley claims that this bird is ‘common’ during the austral winter, sometimes seen feeding with Little Bronze Cuckoos, but the official records say otherwise. As it stands, it appears that our sighting is the 11th one, and in a new location too. In line with the other sightings which were all less than 1km from the sea, I checked the maps and confirmed that our cuckoo was similarly found less than 1km from the sea, just a stone’s throw from Raffles Marina.

Kim Seng’s article mentioned that most Horsfield’s Bronze Cuckoos appear to be on passage with the longest stay at any location being 7 days. He conceded that it is likely that this cuckoo has been overlooked as evidenced by an apparent influx of four different birds between June and July 2008.