Archive for August, 2007

Brahminy Kite: Nesting observations

aaa32.jpg

In March 2007, Mark Chua came across a nesting pair of Brahminy Kites (Haliastur indus) (above) raising two large chicks in a nest lodged high up in the fork of a tall casuarina tree (Casuarina equisetifolia). He managed to document the chicks in the nest, their fledging as well as many dramatic flight shots.

bbb7.jpg

Like most other raptors, the nest is a large, untidy pile of sticks (left). According to Naoroji (2006), the nest is usually lined with common discarded items like rags, strings, pieces of plastic, etc. However, this cannot be confirmed here as the images failed to show other than twigs. It is also reported that the birds build a new nest each season, sometimes recycling the old nest materials, at times even reusing the old nest after some repairs.

Wells (1999) states that the inner cup of the 60-90 cm diameter and 15-30 cm deep nest is lined with a pan of dried mud, 10-15 cm across.

Two or even three eggs are normally laid and both sexes share in the incubation duties. In this instance two chicks were raised (left bottom).

11134.jpg

As reported by Wells (1999), food is often eaten directly while soaring (above).

This large kite has a striking plumage of rufous-brown and white as an adult. The head, neck to mantle, and throat to upper belly and flanks are all white. In the nominate subspecies, indus, that is seen in the Indomalayan region, the white has finely darkish streaks (top).

11135.jpg

From below in flight, the white head, neck and breast contrast sharply with the chestnut lower belly, deep chestnut underwing-coverts with pale chestnut-buff under flight feathers with contrasting blackish primary fingers (above).

aaa33.jpg

The juvenile is mostly brown, and this has been reported to vary with the season. From below the white-tipped underwing-coverts and large white wing panels are prominent (right).

Input by YC, images by Mark Chua.

References:
Naoroji, Rishad (2006). Birds of prey of the Indian subcontinent. London: Christopher Helm.

Wells, D.R. (1999). The birds of the Thai-Malay Peninsular. Vol. I, Non-passerines. Academic Press, London.

To flash or not to flash?

Don’t get me wrong. I am not advocating flashing as this may involve breaking the law. What I mean is flashing from the photographer’s point of view, especially when birds are the subjects.

11125.jpg

Birders and photographers have always argued about the use of flash in bird photography. On the one hand flash photography results in a better image (it is a matter of one’s point of view), especially when the lighting is low. It also removes shadows that may be deemed undesirable. Again, far shot with a long lens will result in a blurred images unless flash is used. Anyway there are many reasons why flash is used.

On the other hand many birders are against using flash, especially on nesting birds and at night, when photographing nocturnal birds. With digital photography, it is not unusual for one photographer to release a dozen or more flashes per session. Imagine the stress on the birds, especially when the distance is near. And with nocturnal birds, not used to bright light in the darkness of the night, the constant flashing can result in injury to the eyes, or so birders claim.

A recent article from the internet titled “Flash Photography and the Visual System of Birds and Animals” by Dennis K. Olivero, DVM and Donald L. Cohen, MD may, in a way, put to rest the fierce controversy that is raging in the interne.

According to the authors the flash gives a very short burst of light that is much diffused when it reaches the subject. This may or may not bother the subjects. However, under dim light conditions, flash “can produce a temporary reduction in vision but not permanent damage.”

The authors are not in favour of repeated flashing in total darkness, however, “The judicious use of flash in completely dark situations causing a brief vision alteration must be offset by the educational value of the photograph made… In select situations, the use of flash may be justified.”

Thus flashing is not a problem during daylight, if not used incessantly and very near nestlings that are not able to fly off. Controlled use of flash at night is not too much of a problem. However, use of powerful lights eg searchlights, to photograph nocturnal birds should be discouraged

Tanimbar Corella: A wasteful eater?

aaa23.jpg

On the evening of the 23rd July 2007, at about 6.00 pm, I heard a sharp cry of the Tanimbar Corella (Cacatua goffini) coming from the starfruit tree (Averrhoa carambola). The bird is usually shy and will fly off as soon as it sees me. But this time I was behind the glass window of my bathroom about slightly more than a metre away and could observe at close hand. It did eye me on and off but by not moving my head it was not bothered by my presence. It continued picking on the fruits.

The lone bird was perching on the branch. It reached out to a young, green fruit with its bill and expertly plucked it from the short stalk (above left). Then, with the right foot gripping the branch, its left foot moved up to take hold of the fruit. With its sharp pointed bill, it bit off bits and pieces of the fruit along the flange and dropped them below. Then it dipped its bill into the core of the fruit and extracted the seeds inside (above right).

11131.jpg

One by one it plucked the green fruits from its perch, ate the seeds and dropped the remaining fruit below (right). When it finished with the fruits around, it walked along the branch to another spot and did the same. All the time it was eating, it gave out a harsh, monosyllable sound.

For some time now, I have been under the impression that the bird is a wasteful eater, eating pieces and then dumping the rest of the fruit. Obviously I was wrong.

Input and images by YC.

Sleeping Chestnut-naped Forktail

Since the posting of Sleeping Birds earlier on, a few people have written expressing concern about disturbing these birds in their sleep, especially when flash is used to photograph them.

chestnut-napedforktail-for.jpg

Forest Ang is one such concerned person. He was at Maliau Basin, Sabah when he came across a sleeping bird when out frogging along a small stream one night (left). The sleeping bird had its head buried under its wing.

“I took this sleeping Chestnut-naped Forktail (Enicurus ruficapillus) on a branch over a running stream. It was curled into a ball. I saw several mosquitoes on its toes. I think it got a fright when it suddenly woke up to see a shining torchlight. It flew aimlessly like a drunken bird.

“I really felt sorry for the intrusion. Perhaps we photographers should restrain ourselves from getting too near. It could hit a tree and injure itself in the darkness.

“I had a few previous encounters with sleeping birds but all of them were not bothered with my presence.

“After the Chestnut-naped Forktail, I have been restraining myself from the urge to take pictures of sleeping birds…should we? What is your comment?”

See Forest Ang’s video here!

Yes, flashing sleeping birds may disturb them. As I earlier posted in reply to Serene, some birds may actually be disturbed, waking up for a moment, to go back to sleep. Others may be oblivious to the flashes and continue sleeping…

Personally, I think there is nothing wrong with taking photographs of sleeping birds, as long as we do not overdo it. It is the same with photographing nesting birds. How else do we add to our knowledge of bird behaviour? We do need such documentation. Taking photographs is a lesser “evil” than taking specimens of animals for study.

As long as we do things in moderation, we would not be disturbing the birds too much. It is only when a few photographers descend on the scene, each releasing a dozen or so flashes at the sleeping or even a nesting bird, that we are causing problems.

Input by Forest Ang, image from his webpage.

Golden-bellied Gerygone and Little Bronze Cuckoo chick

1115.jpg

A pair of adult Golden-bellied Gerygone (Gerygone sulphurea) were spotted frantically feeding the chick of the Little Bronze Cuckoo (Chrysococcyx minutillus) in fig tree in a park in early August 2007. The adult gerygone is a smallish bird about 10 cm long while the cuckoo is 16 cm long. Or that is what the guidebooks say. However, the images captured of the feeding pair show the cuckoo chick to be nearly twice as large as the gerygone adult (above and below left).

The gerygone, being small, can only catch small insects. The chick, being large, was not easily satisfied by the number of small insects fed to it. The result? The foster parents had to work frantically like feeding machines to appease the hungry and noisy chick. And this went on for days on end.

bbb6.jpg

And there was an adult cuckoo in the vicinity. Was it keeping an eye on its chick? To ensure that the foster parents were taking good care of its biological chick? Food for thought eh?

There was only one cuckoo chick (above right). I suppose the small nest of the gerygone cannot handle more than one large chick. And to be left with two large cuckoo chicks to feed will be too much for the adopted parents.

The Little Bronze Cuckoo is a brood parasite, laying its egg in the nest of the Golden-bellied Gerygone. Once the cuckoo’s egg hatches, the chick will eject the eggs of the host.

Input by Eddie Lee and Daniel Koh; images by Daniel (top) and Eddie (bottom).

Next Page »

Welcome to the BESGroup website


"You can know the name of a bird in all the languages of the world,
but when you're finished,
you'll know absolutely nothing whatever about the bird...
So let's look at the bird and see what it's doing - that's what counts.
I learned very early the difference between knowing the name of something and knowing something."

Nobel Laureate Richard P. Feynman (1918-1988)

Locations of visitors to this page