Asian Openbill (Anastomus oscitans) in Flight

Asian Openbill (Anastomus oscitans) as i was made to understand, comes from a larger group of stork family named "Ciconiidae".  It was reportedly a resident bird in India, Mynmar and Thailand* and rarely reported in Malaysia until year 2008 when a lone bird was spotted in Perlis by Kim Chye, his wife and Mr OoiBY. (* info taken from Bird Life International).

Based on the records in B.i.W, there were reported sightings of Asian Openbill almost every year in Peninsular Malaysia except in year 2009 and 2012. There were no sightings being recorded in Borneo so far. Here is a summary of the statistics compiled from B.i.W as at September 16, 2014:

Year         Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sept   Oct   Nov   Dec   Total

2008         -         -        2       -         -        -       -        -         -        -        -        -          2

2009         -         -        -       -          -       -        -        -        -        -         -        -          0

2010         -         -        -      27        -       -        -      20      15       25     11     10       108

2011        10      17       -      -          -       -         -       8        -        10       -        -         45

2012         -        -         -      -          -       -         -       -        -         -         -         -          0

2013  3177   1737   452  3280  5113    1   3847   150    292     155   200      1   18405

2014  1592  1228   171      80    350    6         3      -     700        0         0       0    4130

Total: 4779  2982   625   3387   5463   7   3850  178  1007     190    211    11    22690

The above table shows that year 2013 has recorded the most sightings of Asian Openbill (18,405) while January (4779), April (3387), May (5463) and July (3,850) were the months which have the most Asian Openbills sighted and June (7) been the least. However like all statistics the above numbers only provided a rough estimates of the birds seen as their numbers can be fewer than the overall total of 22690. This could be due to the same flock flying from one state to another while looking for their favourite food which were mainly snails. For example in the month of April 2013, the birds were seen in Penang, Perak, Selangor and right down to Melaka.

Recently i had an opportunity to witnessed a huge flock of Asian Openbills at Air Itam Dalam Forest Reserve, Penang. Usually i could only managed to see about 2 or 3 birds at any one time but on 16 September 2014 alone the numbers were close to about 1000. Have a look here:

From below, it may look like another stork with its long bill

At about 11.15am, a few birds came by and were circling around, probably waiting for the thermal to build up

Some can be seen panting here. Could they have flown in from a distance?

Then out of nowhere came a huge flock 

Wave after wave of them came from all directions

As i was observing the initial group, then i realised that there was another bigger group circling higher then the initial group. Holly Molly! there were actually two groups which have appeared.

Some flew so high that they almost reach the moon :-)

From the above photo, you can see that Asian Openbills do not have a systematic way of thermaling. They can be seen circling in different directions - some can be seen moving towards the camera, some were heading to the right while some were moving to the opposite direction. This uncoordinated flying has resulted in some near misses as can be seen from the photos below:

Fortunately they are excellent flyers and any fatal mid air collisions have thus been avoided.

Can you spot the odd one out?

Yup! it was a  juvenile White-Bellied Sea Eagle which had also appeared.

The raptor did not join the main group and at times it was seen circling alone.

It was also seen circling quite close to this juvenile Asian Openbill on numerous occasions but i did not see it attempting to size the young bird. I have only seen photos of White-Bellied Sea Eagles eating fishes and snakes but not of them devouring other birds. For its size it can be a formidable predator but this time i guess it had just wanted to enjoy the company.

A closer look at the juvenile / sub adult. You can see the difference in the color of its primaries.

At about 12 noon, the lower group departed towards Bukit Mertajam - southwards while the higher group flew towards east - i.e. towards Kubang Semang/Lunas.

Surprisingly the eagle also followed the initial group - southwards.

All i can say that this was indeed a spectacular phenomenon of aerial display which i have never seen before !


Choy Wai Mun said…
Impressive, aren't they...I sometimes still cannot get use to this sight although they have been around for more than one season.
Ronnie Ooi said…
Hope you can see them when they make their return journey.

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