Thursday, 6 April 2017

Chestnut-headed Bee-eaters; the large ‘cliff’ colony on Penang Island

As this article describes behavioral characteristics of Chestnut-headed Bee-eaters and Kek Lok Si temple it is pertinent to first summarize these key subjects in the following article.

Chestnut-headed Bee-eaters
The Chestnut-headed Bee-eater (Merops leschenaulti), also known as the Bay-headed Bee-eater is a near passerine bird in the Bee-eater family Meropidae. It is one of 27 species of Bee-eaters worldwide. It is a resident breeder in the Indian subcontinent and adjoining regions ranging from India east to Southeast Asia, including Thailand, Indonesia and Northern peninsular Malaysia. The species, like other Bee-eaters, is a richly coloured, slender bird. It is predominantly green, with blue on the rump and lower belly. Its face and throat are yellow with a black eye stripe, and the crown and nape are rich chestnut. The thin curved bill is black. The sexes are alike but the chicks are overall duller with a green head. The species is 18-20 cm long and does not have the elongated tail feathers of most other Bee-eater species.

The following images document the breeding cycle of the Chestnut-headed Bee-eaters in a 'dirt-mound' based colony in mainland Penang State on Peninsular Malaysia. The activities consist of pairing, romancing, feeding, nest excavation, mating, nest feeding and fledging of the chick(s)

Kek Lok Si temple.
The KEK Lok Si temple is a Buddhist temple situated in Air Itam on Penang Island facing the sea and commanding an impressive view. The entire complex of temples was built over a period from 1890 to 1930, inspired by Beow Lan, the Abbot at the time. The focus of attention in the complex is the striking seven-story Pagoda of Rama V1 with 10,000 alabaster and bronze statues of Buddha, and the 30.2 metres tall bronze statue of Kian Yin, the Goddess of Mercy.
The complex is spectacularly lit over the Chinese New Year period.

I have followed the mating and nesting habits on a colony of Chestnut-headed Bee-eaters on the mainland of Penang here. Unfortunately, the numbers have been diminishing in the last 5 years to the point of almost complete cessation. In 2017 there is only one breeding pair.

I had been told that there were Chestnut-headed Bee-eaters around Tek Lok Si temple on Penang Island. I had a cursory look several years ago for nesting areas but was not successful. I had a friend, Nick Baker, from Singapore visit last weekend and we decided to have a more serious look for the location of the temple breeding colony. My wife, Helen had visited the temple over Chinese New Year and observed Bee-eaters flying above the temple on hunting excursions. I was given an approximate location of where the colony might be by a birding friend. We drove down the road that bisects the temple with the Goddess of Mercy statue on the higher side of the road and the temple proper on the other side. We parked the car and searched along several tracks beyond the temple without success. There was no Bee-eaters flying around either. Slightly disappointed we started heading back home….not far along a Bee-eater flew across our path. I stopped the car and a quick observation showed quite a number of Chestnut-headed Bee-eaters flying in the ‘canyon’ between the lower temple building and walls that are immediately beneath the Goddess of Mercy statue. They were perched on the buildings and reinforcing steel that protruded from the walls. The walls above the road height had rows of PVC drainage pipes….these were 58mm in diameter and around a metre into the bank. We observed several Bee-eaters flying into these pipes and staying for over 10 minutes and other flew in and out within 3 minutes. In the latter case, there were several repeat visits in the following 30 minutes which was indicative of chicks being fed.

A close-up view of the drainage holes taken from the upper left-hand side

The location of the observations

The temple Bee-eaters

We returned the following morning armed with our longer lenses to get proof that feeding of chicks was taking place. This evidence was not difficult to get as feeding in some holes was regular. In 120 minutes we identified 15 holes that were frequented by Bee-eaters with cargo. In other cases, one of a pair was catching insects and bringing them to the mate. This occurs at two periods during the breeding cycle; prior to coupling and when the female is laying eggs. We estimated that there was a minimum of 50 birds in the colony……there may be well over 100. It is the first week of April and evidence indicates that nesting is an a relatively early stage as the size of the food taken into the nests is small. This is quite different time period from the mainland colony I have observed where nesting would essentially be over by this time.

Breeding Behaviour

 The PVC pipes are also utilised as nesting holes by Crested Mynas.

Earlier in the year I had mentioned to other friends, Derek and Jane Harrington, who live in a condominium towards Batu Ferringhi about the Chestnut-headed Bee-eaters. They said there was a large retaining wall behind their unit where they had observed Bee-eaters frequently flying into the PVC drainage pipes. The Bee-eaters seemed to prefer the higher ones which were around 50mm as opposed to larger lower pipes. In both locations drainage wtaer has not been observed flowing form the majority of the pipes in question.

                                                                                                           Photo by Derek Harrington

These two observations strongly indicate that Chestnut-headed Bee-eaters have adapted to man-made structures and use them for nesting. The two locations are similar; they are at a similar elevation and have the catchment area of the forest-clad Penang Hills behind and above. In both cases there are trees the birds like to sit in as hawking trees where they can observe prey on the wing and swoop down after them.

The hawking tree at Kek Lok Si

What are the pros and cons of PVC pipe nesting as opposed to dirt mound nesting. I have documented the hazards another species of Bee-eater that nests in dirt mounds must overcome here .These included;
1.     Predation by snakes, lizards and large raptors.
2.     The constant irritation of mites that live in the dirt.
3.     Interference by wild dogs and feral cats
4.     Interference by grazing animals
5.     Infestation with ants and termites (I have seen several chicks been driven prematurely from the nest by invading termites)
6.     Poaching targets.

It is difficult to see any of these being a major problem in a comparatively clean PVC pipe centred cliff colony.

Colony nesting has a major advantage in combined security……with many eyes looking for predators. Several Bee-eater species live in cliff colonies; The White-fronted Bee-eaters, the Carmine Bee-eaters (both African species) and the European Bee-eater. Essentially the Kok Lok Si colony is a cliff colony….although the holes are designed by man.

White-fronted Bee-eater

White-fronted Bee-eater cliff colony

Carmine Bee-eater cliff colony

European Bee-eater cliff colony
The above is a good illustration of nature adapting to the presence of man and man-made objects. It may possibly explain why so-called natural sites for nesting of this species are diminishing. There must be other retaining walls around Penang Island that are also utilised by this species of Bee-eaters in a likely safer environment for them.

A note to Penang photographers and birders; It would be good to hear about other cases where such structures are used by our local Bee-eaters.

Thanks to Nick Baker who collaborated with me on this project

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