Sunday, 1 January 2017

Where have all the Chestnuts gone?

I came to live in Penang in August 2011. To start my local photographic journey a friend had given me 4 GPS co-ordinates. They were for; Byram, Batu Kawan, Air Hitam Dalam and Penanti. Both Byram and Penanti were the top locations visited in the subsequent 5 years. Byram was downgraded by a mindless manipulation and I have feared Penanti, a moto-cross track might disappear under a palm oil plantation or mass-produced terrace-row housing. Batu Kawan never held much attraction and Air Hitam Dalam is always worth a visit but Penanti has been a nature photographers dream if you are into actions and behavioral images. The main stars have been the Chestnut-headed Bee-eaters, the Blue-throated Bee-eaters and the White-throated Kingfishers…..all involved in ground-based nesting cycles.. I have been eternally grateful for these subjects and the time I have had with them but it now appears we have lost one of the stars……this season the Chestnut-headed Bee-eaters have not shown up.

In my first season in 2012 there were estimated to be 50 plus Chestnut-headed Bee-eaters that arrived in late November to nest in the mounds. In the following year the numbers had dropped slightly to 30-40 individuals. In 2014 there was another slight reduction to around 30 birds. In 2015 the number was 20-30 individuals. 2016 saw a drastic reduction to only 5 birds. There was no apparent nesting during this year. At the start of the 2017 season two birds were observed several times but by the end of t2016 there were no Bee-eaters present. It is difficult to point to any major reason for the reduction. These birds are endemic to the region and 1-3 birds can sometimes be seen on high perches near bush-clad hills. Photographing the species outside the breeding season is almost impossible as they perch high up and are always on the hunt. The species at Penanti tolerated noisy motor-cycles while nesting as well feral dogs, snakes, termites and aggressive bird rivals. The track is used less but other than the removal of some trees on the periphery no obvious changes have been noted. The Blue-throated Bee-eaters migrate in February and were always there in greater numbers from 60 to 150. It appeared to me the numbers of of the Blue-throated may have been reduced in 2016 but not severely. Fellow photographers inform me that they have also seen less numbers recently of Chestnut-headed Bee-eaters in other areas of mainland Penang, although there have been no official or scientific counts.

The Chestnut-headed Bee-eater (Merops leschenaultia) is a small, brightly coloured Bee-eater. The adult has a bright chestnut-brown crown and mantle. The wings are green with a broad black band on the trailing edge, which is more conspicuous in flight. The rump is azure to pale turquoise. The tail is green with a bluish tip. The central pair of retrices is greener than other upper-tail feathers, but this species lacks the elongated tail-streamers. The underparts, chin, cheeks and throat are yellow whereas the lower throat is rufous. A narrow, black gorget is visible along the lower throat border. The upper breast is yellow, turning green in the lower breast. The belly is blue-green, turning blue in the under-tail coverts. The underwing is pale chestnut brown with a black trailing edge. On the Chestnut-brown head there is a black mask formed by black lores and eye stripe below the eye. The down-curved, pointed bill is black, the eyes are red, surrounded by a black eye-ring. Legs and feet are blue-grey. The male and female have a similar appearance.

There are three sub-species with the main species found in South India and Sri Lanka, North India and Nepal, China, Indochina and the Malay Peninsula. Other sub-species are found on Andaman Islands and Java and Bali.

The Chestnut-headed Bee-eater is found at forest edges and in clearings, as well as open spaces in forested country, large gardens, along riversides and sometimes in plantations.

It is a joy to watch these Bee-eaters hunting. The favourite tactic seems to swoop on flying prey from the top of a tall tree. There is usually an audible 'thwack' when the strike is made. They also take off after prey from low perches and seem very accurate. I have all the windows of my vehicle open and several times I have had a pursing Bee-eater fly through the car rear windows. They are tolerant to photographers in hides or the best hide of them all....a vehicle. Prey is tossed and beaten on perches to subdue it and in the case of bees to squeeze out the sting. Chestnuts seem to be very exuberant tossers of prey compared with other species.

The breeding season starts with paired bird hunting from the tops of tall trees. The main prey at this stage seems to be Bees and other small insects with the occasional butterfly. 

The pair after a few weeks will start excavating their nest hole in a dirt mount. Often on bird picks the dirt loose while the other kicks the debris away from the hole. This process make take several weeks to a month. 

Bee-eaters have mostly paired off before arriving at the breeding ground. There are certain human traits with their courtship;


Looking into each other's eyes

Lustful looks

 ........and indecent proposals

Mating occurs around this time with the pair sitting close together until the female assumes a ‘mount me’ position. Mating is a flurry of activity with wings and legs in all directions. Mating is often preceded by gift-giving where the male will offer the female an insect prior to mating. Gift giving also occurs when the female is egg-laying. The male seemingly aware of the nutritional strain on the female during this period.

Human males may be familiar with the following sequence, where bugs are substituted for jewelry, chocolates or flowers..

The female will lay 4-8 eggs in the burrow. Incubation takes 4 weeks. 

The hatched brood will then be fed by the parents and sometimes a related bird(s) for the next 4 weeks. There will be a constant stream of deliveries into the interior of the nest. Near the time of fledging the chicks will position themselves near the nest entrance and are eventually coerced by the adults to fledge.

The chick above gets his final meal in the nest.....the adults will halt feeding or stand back with food in their bills to lure the chick from the nest. 
Newly fledged chicks have green coloured head. The newly fledged chicks may assist in feeding their siblings if a second nesting is initiated. 

I may be accused of anthropomorphizing but these cute little Bee-eaters even appear to have a sense of humour.

We had one from down-under

One who liked doing chin-ups 

..........and another who crash landed badly while chasing a bee. 

One rather cute habit of Bee-eaters is their tail fanning and wing stretching. This is part of their preening ritual and is also necessary to remove small mites etc that adhere to their feathers while they are in their underground tunnels. They are literally in the ground 100s of times while excavating nests and feeding young. Often during incubation they will stay overnight underground.

So let us examine the possible reason for the colony decline at Penanti. Bee-eaters are colonial nesters but live the rest of the year either singly or in small groups of 2-4. There have been recordings of large colonies of various Bee-eater nesting sites in the State of Penang. The colony at Penanti was the biggest that I observed since 2011. The colony size had got down to a critical level of under 20. Below a certain number all the benefits of colony breeding are gone. 

What are the benefits of colony breeding?
1.    There is safety in numbers. There are more eyes to locate dangers and raise an alarm. This collective alarm and subsequent reaction has been observed at Penanti.
2.    Shared duties; Collecting food, monitoring chicks, incubation and brooding can be shared.
3.    Because of proximity to others there is more opportunity to find replacement mates and continue breeding if a mate is accidently killed or 'bird divorce' takes place..
4.    Because predators have a bigger choice there is less chance of individual chicks being killed.

In 2016 the Blue-throated Bee-eaters turned up at Penanti and raised broods. It would therefore appear that local conditions at Penanti are not a major factor. We cannot exclude however there is another reason for the local decline in numbers. It is however sad to say farewell to these charismatic and colorful master fliers from this nesting field.

I would also like some feed-back from other nature photographers and birders in Penang state to give me their observations on the state of Chestnut-headed bee-eaters.

I hope we will be able to view and photograph the following scenes again

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