Tag Archives: Changeable Hawk Eagle

A Witness to a Hunt.

A Witness to a Hunt – Changeable Hawk Eagle. By Thio Hui Bing.


I was about to leave Lorong Halus on a hot and sunny March day 3rd, 2018, just past midday, when I heard and saw two Changeable Hawk Eagles flying some distance away. I took a few record shots of them. I walk slowly back along the road keeping a lookout for other birds.


It was then I noticed a dark colored raptor on a tree about 10-20m away on the right side from the road. It was a dark morph Changeable Hawk Eagle, perched on tree branches fairly high up.  It was behaving normally, looking around, just like what raptors do. I took a few photos and video of it. Just when I was about to leave, it suddenly flew down across the road with its legs hanging swooping down into the secondary vegetation.


The next moment I heard and saw some mynas flying out. I knew the raptor had likely caught a prey. Curiously, I approached with care and wondered if it was still inside. Looking around I managed to see it among the branches some 10m away, on a low perch. I took some more shots of it. It seemed to know that I was watching it. My close presence may have caused it to fly out of the semi thick vegetation to the other side of the road where it was previously.


Unfortunately, I wasn’t quick enough to get a focused shot even though I got it in frame for flying off with its prey. This time it opted to perch on a branch of tall tree,  probably not wanting to be disturbed. After landing on the tree, it hopped and flew to an even higher tree branch. I could still see it with the backlight,  but not see its prey. I took some shots and video of it plucking the prey’s feathers for records, before leaving it in peace.  What an amazing sight to witness its precision hunting skills.





Marsh Hawk-Eagle?


Can you see the head of the Changeable Hawk-eagle popping out above the water hyacinths.

We are used to seeing Marsh Harriers flying low over marshes and open grasslands looking for food. But earlier this week we saw a dark morphed Changeable Hawk Eagle, Nisaetus cirrhatus, diving into a pond at the Kranji Marshes. The pond was covered by water hyacinths which would have look like dry land from above. It disappeared from view for some minutes. We thought that it may be in trouble  having mistaken the hyacinth carpet for a hard surface.


We were relieved to see it jumped up and not stuck in the mud.

Finally it popped its head up above the water hyacinths and start flapping its wings. We were not sure if it was stuck in the soft mud at the bottom struggling to get out or looking for food among the water weeds.

Finally to our relief it jumped up and flew low over the surface of the pond. It then scoop down again as if to pick out something before flying off to a Rain Tree near by.


It is hard to tell even from this zoom image what it is in its talons.

This frame showed that it had caught something. Does it looked like a small terrapin? It must have dropped it as there was nothing in its talons in the next frame. This is very possible as it cannot sink its talons into the harder shell of the terrapin.


We think that it may have dropped whatever it caught as there is nothing in its talons.

The open Albizia and Scrubland behind the marshes have been cleared for agricultural farms. It may be that the Hawk-eagles main preys like changeble lizards, small mammals are gone. Are they now changing to aquatic animals to survive? Further observations will be needed to see if this is true.


Threatened Hawk-eagles nesting at Mount Faber again.

14/3 Just hatch

14 March. We cannot see the newly hatched chick inside the nest. The parent stood guard to make sure that House Crows do not snatch the chick away

I am grateful to Laurence Eu for alerting me to this pair of Changeable Hawk Eagles, Nisaetus cirrhatus, an uncommon resident, nesting at Mount Faber this March.  They had been nesting at various parts of Mount Faber since 2001 when we found a nest in a Pulai Tree further down the valley.


This time they chose to build its nest high up on a fork in an Ablizia. Luckily it was close to the road. This gave us a great opportunity to study their breeding behavior close up. It is listed as nationally threatened in the Bird Group’s Checklist borne out by less than 10 active nests per season. You can find out more in Tan Kok Hui’s 2011 study on the status and distribution of the Changeable Hawk-eagles in Singapore here.The status and distribution of Changeable Hawk Eagle .

The large nest (left) is made up of small branches that the Hawk-eagle picked up or broke off from the Albizia tree. The Albizias  is favored by the hawk-eagles and fish-eagles for nest sites due to its height. Danger from breaking branches has caused matured Albizia woodlands to be cleared.

Joyce Chia 1 April 2015

1 April. The furry white chick looked to be about 2 weeks old. The parent seldom leave the chick alone at this stage. Joyce Chia’s very timely record shot of the chick and parent.

By the time I went down to document the nesting around mid March, the incubation was unfortunately over. A small furry white “ball” can be seen popping up once in a while from inside the nest. Like all parents, they fussed over the young chick, flying in and out of the nest tendering to the newly hatched chick. It would guard the chick by staying in the nest to defer crows and other predators from an easy meal. It also had to keep the chick dry when it rained and cool when the sun got too hot.

30/4 5-6 weeks old

30 April. 6 weeks old. It spent most of the time moving around the nest checking its surroundings.

13/4 one month old

13 April. About one month old. The wing feathers were well formed. 

According to the many photographers there, the parents would normally bring back rats, lizards, squirrels, common and green pigeons to feed the chick in the morning. They will fly over the nest and drop the prey into the nest for the chick. Later in the day they will pick up any left over food and eat it outside the nest.

7/5  7 weeks old

7 May About 7 weeks old.

15/5 2 months old

15 May. 2 months old. All flight and tail feathers were fully formed. Fledged 3 days ago.

Stnding guard at nest with a chick. 1/4 2 weeks old

The parent bird standing guard by the nest during the first month 

During the first month, the pale morph parent will stand guard near the nest for hours on end while the dark morph parent will be out hunting for food. Unlike some raptors, it is not possible to tell the sexes based on their appearances. The chick’s black wing feathers were well formed by mid April. It can be seen moving around the nest to satisfy its curiosity.

30/4 6 weeks old

30 April. Around 6 weeks old. First observed flapping its wings in the nest. This is an important first step to learn to fly.

By end April, the chick was around 6 weeks old. It was first seen flapping its wings inside the nest. This will help to strengthen its wing. A big bulge at its breast made us wonder if it was deformed. It later disappeared, which meant that it may have been used to store uneaten food.  Even at this stage, the parents were seen bringing back branches to maintain the nest ( per comms. Andy Dinesh).

15/5 2 months old

15 May. It was able to fly from nest to the nearby branch after fledgling 3 days ago 

On 12 May, about 2 months after hatching, Johnson Chua was in place and on time to photograph it taking its first flight out of its nest to a nearby branch without any coaxing from its parents. So we now have an estimated duration of the fledgling of the Changeable Hawk-eagle.


The dark morphed parent did most of the hunting in the morning and would dropped the prey into the nest while in flight. The chick would then fly back to take the food. Later this pale morphed parent would pick up any left over food and eat it at a nearby branch.

The parents would still be dropping food into the nest for the chick sometimes announcing its return with shrill calls. They would end the day with a family bonding time outside the nest in the late evening before retiring for the night.


The chick would perch further away from the nest and wait for the parents, but would stay within the same tree. Its call was very similar to the adults and would use it whenever the parents were about to return with a kill.

At 9 week old, the chick, bottom left in the photo, would be more adventurous and perch further away from its nest.

By the 9th week, the fully grown chick would be more adventurous and started to venture to the other trees nearby. It even flew to the roadside trees to explore and at times perched very close to where the photographers were.

26/5 10 weeks old

26 May. Almost 10 weeks old. Fully grown. It would start to learn how to hunt in a few days time. 

End May, The 10 weeks old chick appeared anxious to do some hunting on its own. C.T. Lim reported not seeing the chick for most of the day. It had flew down to the valley below to join the parents to learn how to hunt for prey. This young hawk-eagle had been the main attraction to the casual visitors, joggers, nature and bird lovers for the past few months at Mount Faber. For the many photographers, birders and fans who have observed its short life span from birth, it had been a privilege. We were delighted that another of our threatened Hawk-eagle will grace our skies and perhaps raise a new brood of its own in the coming years.

Report and photos by Alan OwYong unless stated. Many thanks to all who so generously shared many of the important observations, dates and behavior  with me. 


A Naturalist’s Guide to the Birds of Singapore. Yong Ding Li, Lim Kim Chuah and Lee Tiah Khee. 2013. 

Field Guide to the Raptors of Asia. Toru Yamzaki et al. ARRCN 2012

The Avifauna of Singapore. Lim Kim Seng. 2009.

A field Guide to the Birds of Thailand and South-East Asia. Craig Robson. 2000.

Singapore Bird Report – May 2015

HBC Albert Tan 24 April 15 Horsfield's Bronze Cuckoo Eric Tan.

Albert Tan’s 24th                                       Eric Tan’s 25th. Horsfield’s Bronze Cuckoo

May is the usual slow and quiet month as most of the migrants have left and the residents were in their post breeding period.  But all these were shattered with an influx of the long awaited and rare Austral migrant, the Horsfield’s Bronze Cuckoo, Chrysococcyx basalis.

Apparently it was photographed at Punggol Barat on the 10th by Vincent Lao, but was dismissed as the Little Bronze Cuckoo. Albert Tan and Eric Wang posted their exciting finds on 24th and 25th after reading a timely post by Francis Yap of Lim Kim Seng’s old Horsfield’s Bronze Cuckoo article.

Horsfield's Bronze Cuckoo at Punggol Barat

Horsfield’s Bronze Cuckoo at Punggol Barat

The race was on to find them before they are gone. To everyone’s surprise, there were a bunch of them flying around at the Mimosa open waste land at Punggol Barat. This is Francis Yap’s excited text on 30th: “Got the horsy, Punggol Barat now”, “Lost track of it, near pond”, “Cannot find. Very hot now”, “Found again”, “3 birds now, near pond”, “ 4-5 birds”, “ Lost count liao after 10 birds”. Con Foley was calling this a “Cuckoo Convention”. It was just incredible. In June 2005 we had one adult and one juvenile that stayed for a week at Marina South. The past eight records, all were single birds. This is our chance to study their “wintering” behaviour.

Asian Paradise Flycatcher by Vincent Ng

Asian Paradise Flycatcher by Vincent Ng

The month started well with the sighting of a male white morphed Asian Paradise Flycatcher, Terpsiphone paradise, at Bidadari on the 2nd ( new extreme date?).  Many of us were grateful for the instant alert from Vincent Ng as it was gone the next day, clearly on passage back. Two Von Schrenck’s Bitterns, Ixobrychus eurhythmus, were photographed at Pasir Ris Park on 5th by Billy Goh and 8th at SBWR on 8th by Alan OwYong. They are known to stay late till June. Another late migrant was an adult Tiger Shrike, Lanius tigrinus, picked up at Bidadari on 9th by Lim Kim Seng. A total of 49 Swinhoe’s Storm Petrels, Oceanodroma monorhis, on passage were counted during a private Pelagic trip to the Straits of Singapore on 10th ( Francis Yap). This was the largest flock recorded for the year, a low count compared to previous year.

Eric Wang managed to photograph all three Jambu Fruit Doves, Ptilinopus jambu, adult male, female and a juvenile feeding on the same tree at Bidadari on the same date. These are the uncommon non breeding visitors attracted by fruiting figs. Another uncommon non breeding visitor was an Cinererous Bulbul, Hemixos cinereus, recorded at Belukar trail on the 20th, another new extreme date.

Interesting resident records include a Lesser Whistling Duck, Dendrocygna javanica at the Japanese Gardens, reported by Laurence Eu , Buffy Fish OwlsKetupa ketupu, one at the Singapore Botanic Gardens on 8th ( Richard White) and another at Bidadari on 15th (Er Bong Siong). All are new for the location.

Two eggs belonging to the Large-tailed Nighjars, Caprimuigus macrurus, were found by Lucy Davies on 10th at Wessex, while the chick of the Changeable Hawk Eagle at Mount Faber fledged on the 12th, much to the delight of the  many of its fans ( Johnson Chua). The young eaglet that was rescued and looked after by the vets in Sentosa turned out to be a Crested Goshawk, Accipiter trivigatus This is the first record of this rare resident raptor breeding there. It will be tagged before released back into the wild. Seng Alvin painstaking monitoring of the pair of Malaysian Pied Fantails, Rhipidura javanica, paid off.  He documented the fledgling of two chicks on the 25th. Happy days.

Nesting Malaysian Pied Fantails about to fledge. Photo: Seng Alvin

Nesting Malaysian Pied Fantails about to fledge. Photo: Seng Alvin

20150422_112114 IMG-20150521-WA0003

Crested Goshawk chick rescued at Sentosa in April. Same chick a month later. Ready for tagging before release. Photos; Daniel Seah of SDC.

One crash record came from John Arifin who found a concussed female Jambu Fruit Dove, Ptilinopus jambu, at Winsland House off Orchard Road on 27th. He informed us that the dove managed to fly off on its own after a short recovery.

Reference: Avifauna of Singapore. Lim Kim Seng. 2009. A field Guide to the Birds of Thailand and South-east Asia. Craig Robson Asia Books Ltd.2000. Field Guide to the Birds of Australia. Simpson and Day, Edited by Francis Yap. The above records are taken from the various bird FB groups. pages, reports and forums.  Many thanks for your postings. Many thanks to Francis Yap, Vincent Ng, Seng Alvin, Daniel Seah, Albert Tan and Eric Wang for the use of the photographs.

Crows and Eagle fight over Heron’s Nestings

OLYMPUS DIGITAL CAMERA28 March 2015. Grey Herons, Ardea cinerea, at Jurong Lake. Two nests with chicks. Parent flapping its wings and squawking away very loudly. A Changeable Hawk-Eagle, Nisaetus cirrhatus, perched on top of nest was eyeing its chicks. A Large-billed Crow, Corvus macrorhynhos, kept watch on the next branch.


Second crow flew in to harass the Changeable Hawk-Eagle.


The Changeable Hawk-Eagle stayed on its perch and tried to fend the crows off.


But eventually gave up and flew away. This looked like one species defending another but……


The Crows then flew back and settled on one side of the tree after chasing away the Hawk-eagle. I did not stay long enough to see what happen next. I can only assume that the crows were waiting to strike once the parents leave the nest unguarded.


This is the prize that both were going after. The younger chick can just be seen behind the older chick. The Herons were not agitated with the crows perched nearby. It is because they are smaller than the Hawk-eagle? If any one of you come across any attacks by the crows on the Heron’s nestings, please drop us a line.

Territorial Black-winged Kites


Changeable Hawk Eagle defending itself against a much smaller Black-winged Kite.                       Photo: Francis Yap.

Our common Black-winged Kite (Elanus caeruleus) is the sub species of the larger Elanus genus of Black-shouldered Kite (E. axillaris). It ranges widely from across Eurasia to the Indian Sub-continent, Asia to the Greater Sundas. They were listed as winter visitors in our past records but no migration was observed. The vast open landscape at that time may have helped them to stay. They are mainly found hunting over open grasslands and nest on remote Acacia tree here. They may be small in size but they are aggressive towards other raptors that encroached into their territory. It helped to have a fierce looking face too.


Looking fierce head on                                                Attacking a Common Buzzard from the top

Several pairs may be co-existing close to each other using the tall Casuarina trees as lookout perches. They will fly around looking for prey like lizards on the ground or indulge in some aerial mock fights.  But as soon as a low flying raptor comes into their territory, the mobbing begins. Size does not matter to these kites. We have seen them chasing away larger raptors like the Changeable Hawk Eagles and in this case the migratory Common Buzzard.


Closing in on to a Common Buzzard. 

They adopt the House Crow’s tactics using numeral advantage to harass the intruders. The attack starts from the top, diving down to the point of contact before peeling off with their talons out stretched. A second kite will repeat the same action giving the intruder no chance to defend itself.  Ironically they receive the same treatment when the House Crows try to steal their chicks from the nests.

Ref: The Avifauna of Singapore. Lim Kim Seng. 2009. Wikipedia: Black Shouldered Kite.