Tuesday, 24 July 2012

Chestnut-headed Bee-eaters nesting in Penang


Chestnut-headed Bee-eaters (Merops leschenaulti), unlike the Blue-tailed and Blue-throated cousins are endemic within the Malaysian State of Penang. They are a resident breeder in the Indian Subcontinent and adjoining regions ranging from India east to South East Asia, including Thailand, Northern Malaysia and Indonesia. This species is not found in Southern Malaysia or Singapore but like other bee-eaters is a beautiful, richly colored, sleek bird and a master flyer. It is predominantly green, with blue on the rump and lower belly. Its face and throat are yellow with a black eye stripe. The crown and nape are a rich chestnut. Newly fledged chicks are the same colors except for a mainly darker green forehead and less distinct demarcation between the colors. The species is 18-20 cm long and it lacks the two elongated central tail feathers possessed by the majority of bee-eater species. There are several subspecies that display variations of the color pattern. The male and females have similar coloration but when seen together the males are noticeably larger, with a higher forehead.

A Chestnut-headed Bee-eater adult in prime condition

The male (right) is bigger than the female

Although seen in small groups throughout the year in various locations around Penang around the middle of December Chestnut-headed bee-eaters arrive at communal breeding grounds. For the first few weeks it seems to be re-union time and the various pairs will hunt together from the surrounding taller trees. January and February are the region’s dry months and it is a spectacle to behold as these beautiful flying machines arc down from their high vantage points and power after flying insects. The rapid aerial assault is mostly punctuated by a perceptible thwack as the insect is hit. That mission over the bird will return to a perch to ingest the captured insect. 

On arrival the Bee-eater hunt many insects

Bees are tossed to get them in a position to swallow

Chestnut-headed Bee-eaters are very exuberant with captured insects: usually they are bashed onto a branch to ‘anesthetize’ them and then tossed into the air to get them into a favorable position to swallow them. Bees are a favored food, as their name suggests, and the sting is squeezed out before the tossing occurs. I did not realize until analyzing my images that this species are more ostentatious insect tossers than the Blue-throated cousins. A steady supply of insects presents certain problems in waste disposal. One of the major proteins in insects is chitin, which is a durable, waxy polymer that is very hard to digest. Every so often these bee-eaters, as well as related species, will open their bills wide an expel a small black ball of indigestible insect products.

Insects are tossed with enthusiasm

Synchronized bee tossing

From a photographic viewpoint I was determined to get some shots of these beautiful but deadly fliers (in silhouette from underneath they remind me somewhat of the renown RAF Spitfires). Most of my images were taken with a long lens resting on a beanbag on my vehicle’s open window however flight shots demanded, high ISO, high speeds, a shorter handheld lens and a location away from the restrictions of the car interior. The clear blue skies of the early months allowed for speeds of 1/3000 to 1/4000 second, coupled with modern camera tracking and the reflexes of an Olympic skeet shooter (almost).

The high speed interception

The low level capture

After settling into the nesting area the pairs of Bee-eaters descended to the undulating terrain and started drilling exploratory holes. As with their Blue-throated cousins the compacted soil was loosened by their pick-like bills and the soil was then kicked back out of the way. It was a joint effort and the pair would often be seen working in unison with one loosening and the other shifting. Sometimes one member of the partnership would be too close behind the dirt kicking operation and get a face-full.  After a few weeks it could be seen where the serious nest cavities were being constructed by the piles of ‘tailings’ outside the entrance.  I located 12 of these potential nests in the general area. It later appeared that some of them were abandoned and only 6-8 nests were being frequently attended some weeks down the line. It was at this time that the Blue-throated Bee-eaters arrived in greater numbers and although they appeared to respect each other’s boundaries I wondered if the change in dynamics caused some nest abandonment.

Nest-hole drilling is a cooperative event

Loosened soil is kicked away

Bee-eaters are such delicate and efficient flying machines and it seems contradictory to best logic that they nest underground and must drill the holes themselves. It seems to be the equivalent of fitting the latest jet fighter with a ditch digger or asking a refined lady in her Sunday ensemble to dig the vegetable garden. Survival however needs adaption but serious preening is needed to keep  flying feathers in good shape and considerable time is spent preening. These sessions are punctuated by wing stretching and tail fanning that can be quite graceful and balletic. At the start of the season the Bee-eaters arrived in prime condition but after digging in abrasive soil some of the birds showed the rigors imposed by their mode of reproduction.

Tail fanning and wing stretching during preening

After nest construction began couples were observed mating on their favorite perches. One day around two weeks later it was like Mothers Day; females were stationed on various perches while the males were operating at full throttle to supply them with insect presents. This apparently is about building the female up nutritionally to fulfill the demanding role of egg laying.

The larger male (left) offers his partner a dragonfly

I followed three active nests over the next month. The suppliers were very industrious in maintaining a steady flow of insects. As with the Blue-throated Bee-eaters each of these nests was supplied by three to five birds, including younger birds likely from last nesting. As the chicks reached maturity the feeding got quite frenetic and sometimes two or three birds would arrive within seconds of each other to hand over insects. In one nest there was only one chick and it stationed itself just inside the entrance and gulped down everything offered. It later ventured a look at the world but stayed inside the hole to continue getting fed. The next morning the chick had gone and the nest was amazingly quiet.

Feeding the chicks; a variety of insects are captured

A constant stream of helpers bring insects to the nest entrance

Cargo includes beaten butterflies........

---------and red Dragonflies

The last chick gets the first view of the outside world
Graeme Guy July 2012


3 comments:

  1. Excellent collection of an iconic species of Penang.

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  2. Your photography is stunning but these Bee-eater images are some of the best bird images I've seen anywhere, so beautiful! It's a bird we don't get in the UK and one I would love to see. You seem to live in a wildlife photographers paradise and you've done such a fantastic job of capturing it.

    Frank

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  3. Superb images mate. I am planning to come down for a visit this month and was hoping to catch some Chestnuts in action. These images are really inspiring. Would be an honor to meet up with you and do some birding if you are free. I will be coming from the 12th-16th this month. Have a great day!

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