At Kinabatangan in Sabah, Lena Chow had a night cruise along the Menanggul tributary where she spotted a few sleeping birds. These diurnal birds were not too bothered by the vessel or the naturalists on board as efforts were made to minimise any disturbance.

The Stork-billed Kingfisher (Halcyon capensis) was obviously aware of the intrusion as its eyes were open (above left). Similarly, the Blue-eared Kingfisher (Alcedo meninting) was somewhat aware of the visitors as its eyes were open although covered with the nictitating membrane (above right). However, the two White-chested Babblers (Trichastoma rostratum) were obviously oblivious of their surroundings. The first, although in is normal perching posture, had its eyes closed (below left). The other bird was comfortably sleeping, with its head tugged under its wing, looking like a furry ball (below right).

Check out our earlier postings on sleeping birds: Blue-winged Pitta, Chestnut-naped Forktail and Common Tailorbird.

All images by Lena Chow.

“Birds flock and roost together for many reasons. One reason I can think of is that as a collective unit, they are more alert with many pair of eyes that are able to look at different directions. Thus, the probability of spotting a predator will be increased significantly.

“A flock of birds consisting of Pink-necked Green Pigeons (Treron vernans) and Asian Glossy Starlings (Aplonis panayensis) was roosting peacefully in a tree one early morning (above). Suddenly, the birds screeched and took flight. Collectively, the birds must have spotted a predator and took evasive action. Sensing danger, the birds were reacting instantaneously. In a split second, all the birds were in the sky and the tree was barren of birds.

“The evasive action took less than two seconds. It was interesting to note that the fastest and first to react were the Asian Glossy Starlings. The Pink-necked Green Pigeons were noticeably slower in taking flight. What spooked the birds? No, it was not a bird of prey or raptor. It was a pair of Oriental Pied Hornbills (Anthracoceros albirostris) flying above (below left).

“The pigeons and starlings were probably alarmed by the large, odd looking hornbills, probably mistaking them for predators. The hornbills were later seen sharing the same tree. However, the smaller birds accorded due respect to the hornbills by perching on the opposite branches of the dead tree (above right).

“The hornbills did not bother the smaller birds but were indulging in preening and allopreening (below). 

It was observed that the female joined the male on the branch and initiated allopreening. There were occasions when she reached below the branch to delicately touch the male’s tail feathers, which she later raised with her bills and preened. Is this part of courtship behaviour?



“I believe that this pair of hornbills have made Pasir Ris Park their home and may be prospecting for a nest. I have spotted the couple on at least three different days over the past fortnight. 

To the officials of National Parks Board, please watch out for the hornbills at Pasir Ris Park when carrying out tree maintenance. The oriental pied hornbills, first originating from Pulau Ubin, then moved to Changi, could have started their highly awaited propagation on mainland Singapore.

 Lets all do our part to help conserve this majestic birds.

”

Kwong Wai Chong
Singapore
16th December 2009

Following the earlier posting of the Daurian Starlings or Purple-backed Starlings (Sturnus sturninus) flocking, Kwong Wai Chong reported his encounter with masses of the these starlings (above).

“A very large flock of Purple-backed Starlings was seen at Lorong Halus about 6pm on 10th October. I counted more than 600 birds in one of the photos taken. As the photo covers only about 2/3 of the flock, I estimated that there were at least 900 birds! It was quite spectacular seeing them in flight and changing direction in unity.

“…there were many smaller flocks of Purple-backed Starling which arrived in waves. The large flock was first seen from a distance… Then, smaller flocks arrived at different times. Probably, the large flock was the result of all the smaller flocks congregating together for a common roosting place (above). Or could it be that the larger flock was broken down into smaller flocks? I can only guess as the fly-past was too fast and over too wide an area for me to see.”

There was also a very small flock of Asian Glossy Starling (Aplonis panayensis) that happened to be around the same area at that time.

“At Changi Business Park late this afternoon, one of my habitual weekend dog walking haunts, I saw a flock of at least 100, perhaps double that, Daurian Starlings (Purple-backed Starlings) (Sturnus sturninus). At first they were flitting from tree to tree near the large lake, chirruping away to each other, and it took me a while to work out what they were - despite their relative commonness, I have never actually positively ID’ed one before. 


“About ten minutes later I came across them again, and something flushed them from the trees they were in. They instantly coalesced into a formation and soared and swooped and whirled, the late afternoon sun catching their pale underparts.

“A beautiful sight, and one I have not seen in Singapore before. It reminded me of my childhood in England where I would see vast cloud-like flocks of Common Starlings (S. vulgaris, though I didn’t have any idea then, other than just ‘starlings’). 

It made my day!”

Howard Banwell
11th October 2009

Note: The Purple-backed Starling is a common winter visitor and passage migrant to Singapore, flocking in large numbers in many parts of the main island. Such sights can be seen around September-October and again in March. An earlier post can be seen HERE.

On the morning of 22nd August 2009, Chris Lee a.k.a. chrisle023 came across about 20 Savanna Nightjars (Caprimulgus affinis) roosting on the ground of a scrub area in Singapore. Unfortunately the area has now been developed into a race track and the birds need to seek out a new roosting site.

Nightjars roost and breed on the ground. The site must be able to provide camouflage to allow their plumage to blend in with the surroundings. At the same time the roosting birds must have a good view of any approaching danger.

The birds normally arrive at the roosting site before dawn and leave at or during the twilight period of dusk. When the weather is dull and overcast, they may roost slightly earlier. During the period of roosting, they may wake up for short periods to preen, stretch their wings or gape widely. They may even move if they are in direct sunlight or are too long in the sun. They may shift their position to face the sun so as to reduce tell-tale shadows or even move from cooler and shadier place to sunbathe.

They leave their roosting site at or during the twilight period of dusk, slightly earlier when the weather is dull or the sky is overcast. Such site is often used and reused unless the birds are disturbed.

The birds roost alone or in pairs. However, during the non-breeding season, nightjars may roost semi-colonially, as seen here.

Image by Chris Lee.

Reference:
Cleere, N., 1999. Family Caprimulgidae (Nightjars). In: del Hoyo, J., Elliott, A. & Sargatal, J. (eds.), Handbook of the birds of the world. Vol. 5. Barn-owls to hummingbirds. Lynx Editions, Barcelona. Pp. 302-386.

This post is a cooperative effort between NaturePixels.org and BESG to bring the study of bird behaviour through photography to a wider audience.