Monthly Archives: March 2021

The Gangster Monitor Of PRP

by Seng Alvin

The Malayan Monitor Lizard, Varanus salvator, is the most common of the three lizard species found in Singapore. It is also the largest, growing up to 3 meters in length. They feed on crabs, fish, frogs and small vertebrates. They are also not fussy eaters helping to clean up rotting fish and carrion.

As an apex predator, their numbers have grown in many parts of Singapore including Pasir Ris Park, my backyard. I likened them to “gangsters” here, attacking all the other species in the park whenever there is an opportunity

One such opportunity came on the morning of 10 March 2021, I was on my usual birding walkabout stopping first at the main bridge across Sungei Tampines. Every thing was calm and peaceful. A few Black-crowned Night Herons, Little Egrets and Striated Herons were happily foraging by the bank of the river.

Suddenly I saw a Black-crowned Night Heron, Nycticorax nycticorax, dropped into the river. I did not see how and why it fell. It was struggling in the water trying to get out, sending ripples across the river. This attracted a Malayan Water Monitor lurking nearby. Immediately it swam over and start attacking the heron in the water. There was nothing I can do except to document the attack.

Most unusual for an adult heron to suddenly fall into the water.

The heron put up a fight and managed to fend off the monitor lizard. But it was clearly injured from the bite of the lizard. I can see a few of it’s white feathers floating in the water.

A few feathers came off after the first attack, It must have been injured.

The monitor lizard bid its time, circling the wounded heron waiting for the right time to attack again. It’s main concern is from other lizards trying to steal its prize.

After a few minutes the monitor lizard launched a second attack. This time round the heron was too weak to resist. It took less than a minute. It was game over for the heron.

The second and fatal attack giving the heron no chance at all.

With it’s prey in its mouth, the lizard quickly dragged it to the bushes along the river bank to finish the meal away from the prying eyes of the other lizards. After close to an hour, this “gangster monitor” came out of the bushes with the half eaten carcass and swam across the river, showing off its trophy to the many birders and visitors to the park.

Showing off its trophy prey as it swam out of the bushes.

While we have to accept that this is part of the life and death cycle in the natural world, where predation is nature’s way of maintaining the biodiversity, this balance can easily be unhinged if a dominant species expanded out of proportion and becomes a threat to the other wildlife in the ecosystem.

The Black-crowned Night Heron is listed as critically endangered in the 2008 Singapore Red Data Book. The main reason is the destruction and disturbance of its feeding and nesting sites and pesticide poisoning. Our largest colony of 1,200 birds at Khatib Bonsu was wiped out in July 1990 when officials from the Ministry of Environment’s Vector Control and Research Division (VCD) start fogging the mangrove island continuously for months in response to complaints of culex mosquitoes. Since then only a few smaller colonies of 20 odd pairs were found at Jurong Lake, Sungei Buloh and Pasir Ris Mangroves. We need to protect all the breeding sites across the island if we are to see this nocturnal heron survive and thrive.

Reference: Nick Baker & Kelvin Lim. Wild Animals of Singapore.

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

G.W.H Davidson, P.K.L. Ng and Ho Hua Chew. The Singapore Red Data Book.

Lim Kim Seng. Vanishing Birds of Singapore.

Singapore Raptor Report – January 2021

Osprey, 290121, CJ Ubin, TGC

Western Osprey, at Chek Jawa, Pulau Ubin, 29 Jan 2021, by Tan Gim Cheong

Summary for migrant species:

The end of the month seemed to be a good time for scarce migrants. A Himalayan Vulture was photographed in flight at Marina East on the 30th, a Black Kite photographed at Changi Boardwalk on the 31st, and an Oriental Scops Owl photographed at the vicinity of Hindhede Nature Park on the 30th.

The wintering juvenile Rufous-bellied Eagle was spotted at Dairy Farm Nature Park on the 6th and 31st. Only one Chinese Sparrowhawk was recorded, at Telok Blangah Hill Park on the 3rd. Two Jerdon’s Baza were still around the Changi Business Park canal in January.

OHB, 300121, Pelton Canal, Saravanan

Oriental Honey Buzzard, adult male, 30 Jan 2021, Pelton Canal, by Saravanan Krishnamurthy.

Four Western Ospreys were around at the northern areas, thirteen Peregrine Falcons were recorded, often perched on buildings. Of the 61 migrant Oriental Honey Buzzards, one at Changi Business Park on the 17th & 18th appeared to be a juvenile ruficollis. Finally, there were 15 Japanese Sparrowhawks, and 37 Black Bazas.

OHB, 170121, CBP, Peter Wong, maybe ruficollis

Oriental Honey Buzzard, this appears to be a  juvenile ruficollis, 17 Jan 2021, Changi Business Park canal, by Peter Wong.

Highlights for sedentary species:

Breeding-related activities were noted for four species. Two chicks of the Brahminy Kite were observed on a nest at West Coast Park on the 23rd. On the 30th, mating was observed for a pair of White-bellied Sea Eagles at Sungei Buloh Wetland Reserve. At Pasir Ris Park on the 3rd, it appeared that the Crested Goshawks had built a new nest; in the middle of the month, there were two newly fledged juvenile goshawks at West Coast Park; and another two at Sin Ming Drive. And for the Buffy Fish Owl, the owlet at SBWR had fledged and was seen outside the nest on the 9th; at Jurong Lake Garden, another owlet was seen on its nest on the 20th, with an adult nearby; and at Yishun on the 23rd, another recently fledged juvenile.

WBSE, 160121, SBWR, Teo Chee Yong

White-bellied Sea Eagle, in flight with a half-eaten prey (possibly an eel), SBWR, 16 Jan 2021, by Teo Chee Yong.

There were six records of the Crested Serpent Eagle at Jalan Anak Bukit, Goldhill Avenue, Pasir Ris Park, Admiralty Park, Botanic Gardens, and Pulau Ubin. One torquatus Oriental Honey Buzzard was recorded – a male on the 8th at the Botanic Gardens. Ten Grey-headed Fish Eagles were recorded, all near water, eleven Black-winged Kites and twelve Changeable Hawk-Eagles were also recorded. Unfortunately, one dark morph Changeable Hawk-Eagle was found dead in the grounds of a condominium on the 27th, possibly a casualty of ‘window-strike’. Finally, one Barred Eagle Owl was recorded at Rifle Range Link on the 6th and two on the 27th, while two Spotted Wood Owls were seen at Pulau Ubin on the 22nd.

CGH, posted 220121, Wong Sangmen

Crested Goshawk, juvenile, 22 Jan 2021, Sin Ming, by Wong Sangmen.

Table 1

Many thanks to everyone who had reported their sightings in one way or another, and especially to Teo Chee Yong, Peter Wong, Saravanan Krishnamurthy, and Wong Sangmen for the use of their photos.

For a pdf version with more details, please click Singapore Raptor Report – January 2021