Kennie Pan’s close-up study of the Oriental Pied Hornbill (Anthracoceros albirostris) provides an opportunity to examine the details of the hornbill’s head (above).

The black head has bluish-white facial markings – bare circumorbital (meaning around the eye) skin and bare throat patch. The eyes are dark red in the male and browner in the female (not too obvious in the image). A prominent feature is the long, sweeping eyelashes.

The pale yellow, down-curving bill has black markings, with the lower mandible having a black base. Although the large bill appears clumsy, it can be used with surprising dexterity, like delicately picking up a small fig, an insect or even a bird’s egg. At the same time it can be used as a pickaxe to knock off reasonably sized living creatures. The force of the mandibles can be strong indeed, to crush the skulls of small animals and seeds or to dig the ground to collect soil (left). The serrations along the edge of the mandibles allow for better grip of fruits or to grip the fruits to soften them before swallowing. The exceptionally length of the bill allows the hornbill to reach for food in areas that do not support the weight of its body.

At the top of the bill is a large casque, a structure unique to hornbills. It is a hollow structure, supported internally by bony ridges and rods, possibly with some opening to the mouth. This allows it to act as a resonating chamber, thus the loud nasal calls.

The casque here runs to slightly more than half the length of the bill. The male has a larger casque that tapers forward (above). In the female the casque is smaller and blunt at the tip (top). It similarly has black markings towards the front end.

The image on the right clearly shows the asymmetrical wing feathers - stiff feathers with a central shaft, a broad inner vane and a narrower outer vane. They form the predominant wind-catching part of the wing. Note that the dark feathers are white-tipped and free from wear and tear. Above the wing feathers are the rows of coverts, smaller feathers that overlap the flight feathers at their bases.

Whiskered Treeswift (Hemiprocne comata), unlike typical swifts, is able to perch firmly on twigs and branches with the aid of its non-reversible hind toe. It likes to sit in a rather upright posture at a spot where it has a good all-round view of the surroundings.

This image by Low Choon How a.k.a. dominator shows a Whiskered Treeswift perching on a branch and looking backwards. Yes, it has turned 180º which enables it to see at the back.

All birds have long necks. This is not apparent because the neck is folded in an S-shape and concealed by the feathers. The large number of cervical vertebrae that can rotate against one another in all directions allow for such movements. This ability compensates for the lack of eye movement in birds due to the large eyeball in a compact streamlined head that has no space for eye muscles.

An earlier post shows the Common Kingfisher (Alcedo atthis) making a similar 180º head turn, enabling it to preen its tail feathers while still perched on the branch.

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

Chris Lee a.k.a. chrisle023 photographed a Malaysian Night Heron (Gorsachius melanolophus) in the process of changing its juvenile plumage to an adult dress.

The duller juvenile plumage is about to take on the darker dress of the adult with the gradual appearance of patches of brownish feathers on its neck and back.

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

The Silver-eared Mesia (Leiothrix argentauris tahanensis) is a common resident of Peninsular Malaysia’s montane forests.

Dato’ Dr Amar-Singh HSS was at 1,600m a.s.l. in Gunung Brinchang, Cameron Highlands on 27th January 2010 when he became fascinated with these birds.

“The Silver-eared Mesias are … very sociably (usually in a group) and quite friendly. They are delightful to watch, and one of the most colorful,“ wrote Amar. “This female (above right) was just in the right lighting, making photography ideal. She was foraging in a bush with six others just below me in a ravine. The female is generally ‘duller’ with less bright colors, more yellow than orange and has golden or tawny yellow upper tail coverts - red in males (above left).

“Have attached males from last year for comparison. The second picture is a male either moulting or a juvenile transforming to adult male plumage (subadult). Notice the red upper and under tail coverts.”

On 28th December 2009, Dato’ Dr Amar-Singh HSS photographed a juvenile Blue-throated Bee-eater at the Kledang Sayong Forest Reserve (400m ASL) in Ipoh, Perak, Malaysia.

“Blue-throated Bee-eaters (Merops viridis) are one of the few birds reported to breed in Peninsular Malaysia and migrate south (Sumatra/Indonesia) during the non-breeding season. A few overstay each year, often see them at the Kledang Hill and hill stations,” wrote Amar.

The adult Blue-throated Bee-eater has a distinctive dark rufous-chestnut cap and mantle, which is absent in the juvenile. As the juvenile turns into an adult, its deep green crown and mantle undergo post-juvenile moult. As more and more of the green feathers are shed and replaced with rufous-chestnut feathers, patches of rufous-chestnut appear before the entire crown and mantle turn rufous-chestnut (left).