Indonesia’s South Moluccas: part 1 – Ambon, Buru and Yamdena (Tanimbar): 6th – 15th September 2019   Leave a comment

Off all the countries in the world Indonesia is one of the most remarkable. Spread along the equator across almost 50 degrees of longitude with the western point of Banda Aceh on Sumatra level with eastern India and the eastern most point, the border with Papuan New Guinea is almost as far east as Tasmania, it consists of 17,500 islands varying from the huge islands of Sumatra, Borneo and New Guinea to uninhabited ‘desert islands’. It is the fourth most populated nation in the world with nearly 268 million inhabitants yet most people (in the UK at least) couldn’t point to it on a map.

From a biological point of view it is amazing, although the mega-fauna of the large western islands has largely disappeared due to habitat destruction, the bird life is incredible – although similarly threatened by habitat loss. Close to 1600 bird species have been discovered, beaten only by Brazil, Ecuador and Colombia and far in excess of any country that’s not in South America. Two factors can explain this; the multitude of islands had led to the evolution of myriads of variations on a theme, and perhaps more importantly and almost uniquely, Indonesia lies slap across the boundary of two faunal zone with a huge zone of integration between them.

Biologically Indonesia can be split into three zones, the Greater Sundas in the west with their typical Asia fauna, West Papua in the east with its Australasian fauna and between them Wallacea.

 

On the map above take particular note of the channels that separates 1) Borneo from Sulawesi, 2) Bali from Lombock and 3) Halmahera, Seram and Tanimbar from New Guinea and the Aru Islands. Now look at the next map below. – Map of Indonesia from see here 

 

This map of what is now central Indonesia shows the situation at the height of the Ice Ages. So much sea water was locked up in the polar ice sheets that sea levels were considerably lower than now. Note Bali is connected to Java but the channel between Bali and Lombok still exits. New Guinea and the Aru Islands are connected to northern Australia but Halmahera and satellite islands, Buru, Seram, Kai and Tanimbar islands plus all the Lesser Sundas remain isolated. This huge area that was not connected to Asia or Australia/New Guinea is now known as Wallacea after Alfred Russell Wallace, the co-discoverer (with Charles Darwin) of evolution through natural selection and who was the first to realise that this region has a surprising mixture of Oriental and Australasian flora and flora. Map from www.naturalearthdata.com

 

This map shows the Moluccas and is geopolitical rather than biogeographical. The dark blue encircles the administrative provinces of North Maluku and (south) Maluku. Note that the Aru islands are politically part of Maluku but bio-geographically part of Papua and were not visited on this tour. Photo from Wikipedia Commons.

 

This was my third visit to Wallacea. I had visited Halmahera and Sulawesi in 1995 and Timor and other islands in the Lesser Sundas in 2006. The tour started at Ambon, then visited Buru, back to Ambon, Yamdena in the Tanimbar Islands, then back to Ambon, Kai Kecil and Kai Besar, then back to Ambon, a short visit to Haruku (from Ambon), Seram, Boano before returning to Ambon for the flight home.

This post deals with the first half of the tour, Ambon, Buru and Yamdena.

 

I left home on the 4th September for the afternoon flight to Abu Dhabi. I left there in the early hours of the 5th and arrived at Jakarta on Java in mid afternoon. I stopped overnight at the conveniently situated airport hotel and then flew to Ambon where the tour started in the early afternoon of the 6th. I find it annoying when British news refers to almost any island in Indonesia as the ‘the remote Indonesian island of —‘. Ambon Island for example, although only 804 sq km in area has a population of half a million, most of which live in Ambon City, is the capital of Maluku Province and has an international airport. Hardly what I would call remote. Transport is largely by motorbike but that doesn’t prevent the traffic jams!

 

Our first birding was in an area known as Ewang Tulehu. Ambon was connected to Seram during the ice ages and so has few endemics. The only one currently recognised is the Ambon White-eye which we saw well, but we also saw the Ambon form of Seram Golden Bulbul (above) which is a potential split. Photo © Craig Robson/Birdquest.

 

We also had good views of Ashy Flowerpecker, a species that is shared with the island of Seram.

 

Early the next morning we flew west one of the many inter-island turboprop flights to the island of Buru.

 

We arrived as early as 0730 so it was straight out birding. We saw a number of endemics such as this Buru Friarbird, or was it a Buru Oriole? In one of the strangest cases of mimicry in the world, almost every one of the larger Moluccan islands has a species of Friarbird (a large honeyeater) that is mimicked in both plumage and vocalisations by a totally unrelated species of Old World Oriole. The size and slightly downcurved bill makes me think this is the Friarbird but the definitive test is whether the dark area on the face is bare skin (friarbird) or feathered (oriole). Tour leader Craig Robson made the following comments in the trip report. ‘A recently published paper (Jonsson et al. 2016. The evolution of mimicry of friarbirds by orioles (Aves: Passeriformes) in Australo-Pacific archipelagos. Proc. R. Soc. B 283: 20160409. http://dx.doi.org/10.1098/rspb.2016.0409) has tested the hypothesis that regional brown orioles mimic friarbirds. Historical observations by Alfred Wallace and Jared Diamond of plumage similarities between co-occurring orioles and friarbirds led them to conclude that the former represent visual mimics of the latter. Here, the authors used molecular phylogenies and plumage reflectance measurements to test the mimicry hypothesis. The results show that friarbirds originated before brown orioles, and that the two groups did not co-speciate (although there is a plausible instance of co-speciation on Buru and Seram). Furthermore, the greater size disparity between model and mimic and a longer history of co-occurrence have resulted in a stronger plumage similarity (mimicry). This suggests that resemblance between orioles and friarbirds represents mimicry and that colonization of islands by brown orioles has been facilitated by their ability to mimic the aggressive friarbirds’.

 

We also two (rather poorly photographed) pigeons – Spectacled Imperial Pigeon …

 

… and the exquisite Claret-breasted Fruit Dove. One pigeon we didn’t connect with was Buru Green Pigeon, possibly because this tour wasn’t running at the usual time of year and they weren’t visiting their usual fruiting tree due to lack of fruit.

 

We did however see plenty of Black-bearded Flying Foxes. Mammals are scarce in Wallacea. We recorded three species of flying, two cetaceans, an introduced Brown Rat and a single species of cuscus, a marsupial that has somehow crossed the sea from New Guinea to colonise one of the Kai Islands. Western Indonesia has (or has had) the full suite of SE Asia mammals; leopards, tigers, elephants, rhinos, wild cattle etc whilst New Guinea has a large variety of marsupials. A single primate colonised Sulawesi but in general Wallacea is depauperate when it comes to mammals, in contract to the situation with the more mobile birdlife. Photo © Craig Robson/Birdquest.

 

Much of our birding was along this old logging road, but we did make some forays into the forest …

 

… which proved tricky for the shorter members of the group.

 

We reached our accommodation on the north shore just before lunchtime where we searched for seabirds until we went out again in the afternoon …

 

… and we were lucky enough to get close views of Indo-Pacific Bottle-nosed Dolphins just offshore.

 

There were great views at sunset but having been continuously on the go for several days we were glad we weren’t out owling that night …

 

… instead we were out at 0430 the following day and scored with Buru Boobook, Large-tailed Nightjar …

 

… and the diminutive Moluccan Scops Owl. Photo © Craig Robson/Birdquest.

 

We explored other parts of the island by 4×4 …

 

… seeing great birds like the endemic Buru Honeyeater (Photo © Craig Robson/Birdquest) …

 

… and Buru Racquet-tail (named after the unusual racquet-shaped tail feathers which can just be seen on the lower left). Photo © Craig Robson/Birdquest.

 

But one of the best was this gorgeous White-naped Monarch, one of many species in this mainly Australasian family. Photo © Craig Robson/Birdquest.

 

Some of us also undertook an arduous trek into the highlands. Our main target was the legendary Madanga, a bird that was once classified as a funny looking white-eye but genetic analysis has shown (crazy as it sounds) to be an aberrant pipit. However if a group of pipits had been blown to this (once) totally forested island they would have had to adapt to survive and what sort of bird survives well in forested environments in Wallacea, small rotund passerines like white-eyes or flowerpeckers! Nowadays of course pipits could find live a more typical lifestyle in the many deforested areas. Unfortunately we didn’t become the second ever tour group to see the Madanga (the first was the previous Birdquest group) but we did see …

 

… Cinnamon-chested Flycatcher (Photo © Craig Robson/Birdquest) …

 

… and a juvenile Moluccan Cuckoo being fed by Buru Leaf Warblers. Photo © Craig Robson/Birdquest.

 

We had done pretty well on Buru, no Madanga or Buru Green Pigeon, but most of the island endemics were UTB. It was time to return to Ambon. We had time to visit a freshwater lake which added a few quality waders, a Black Bittern …

 

… and the cobalt-eared form of Common Kingfisher to our lists. The rest of the day was spent in forest where a number of new birds (mainly ones we would see again later on Seram) were recorded.

 

We overnighted in Ambon City …

 

… and then flew the following morning to Yamdena in the Tanimbar Islands, the southernmost point of our trip and just 350 km north of the Australian mainland.

 

Our accommodation was built on a pier out into the harbour.

 

Our rooms weren’t ready on arrival and there wasn’t time to go anywhere before lunch so we just enjoyed the view and watched for seabirds.

 

There was a great view from our rooms …

 

… over the nearby waterside shacks and boats.

 

You could even see Lesser Frigatebirds from your bed.

 

Yamdena is much flatter than Buru (or Seram) and so is more prone to deforestation, either clear felling for agriculture …

 

… or by stripping out the tallest trees in the forest.

 

Quite a bit of our time was spent finding our way through dense thickets …

 

… and along watercourses. As I said before the Moluccas have little in the way of terrestrial mammals but domestic water buffalo wander these woodlands and can turn up unexpectedly.

 

We saw a number of exquisite orchids in the gloom of the forest …

 

… and the bizarre ant plants, epiphytes in the genus Mermecodia that have a symbiotic relationship with certain species of ants. The plants give the ants shelter and food, the plant benefs from the protection the ants provide and nutrients from the ant’s dead bodies and waste. The plant grows epiphytically high in a tree (the seed having been deposited there by a bird) and grows these bizarre convoluted chambers to house the ants. This plant has fallen from a tree and split open exposing the ant containing chambers.

 

 

There were many good birds on Yamdena including this endemic Golden Flyrobin (Photo © Craig Robson/Birdquest) …

 

… and another endemic Black-bibbed Monarch. Photo © Craig Robson/Birdquest

 

Near the airport was this wetland area where we saw a number of waterbirds, mainly of Australian descent.

 

Another indication of our proximity to Australia was the presence of several Tree Martins.

 

Elegant Imperial Pigeons which are found on other small islands in the Moluccas and on the Lesser Sundas.

 

More widespread is the aptly named Eclectus Parrots which occurs throughout New Guinea and as far as Cape York in Australia. The female surprisingly in the red one whilst the male is green.

 

With the Eclectus were a number of Tanimbar Corellas, a species of cockatoo, it is endemic to the Tanimbar islands, but a few have been introduced to the Kai Islands.

 

The local xanthogaster race of Rose-crowned Fruit Dove lacks the rose crown! Variation between different races of a wide variety of species in Wallacea is often greater than the variation between different species elsewhere. It is hard to know where to draw the line between species and subspecies, but modern techniques of voice analysis and genetics may provide the answer. James Eaton et al’s lovely book on the birds of Indonesia splits many more forms (but sadly not this one) than do the various World Checklists. So far when detailed studies have been performed he has been shown to be right. Trips to Wallacea will be source of armchair ticks for years to come.

 

A nocturnal expedition got us great views of the endemic Tanimbar Boobook but unfortunately no photos.

 

It was very dry with string winds which is quite unusual in these parts. It made it difficult to traverse the forest quietly. However there were some damp areas remaining and here we located one of the loveliest birds of the trip …

 

… the endemic Slaty-backed Thrush. Photo © Craig Robson/Birdquest.

 

But there was one bird that really eluded us. Its presence was obvious from the raised mounds in the forest that it constructs to incubate its eggs. I’m talking about the elusive and endemic Tanimbar Scrubfowl. We searched high and low, occasionally the person at the front next to the leader would get a glimpse, but I usually missed. Eventually one was located in a tree and I got a brief view as it shot away.

 

Photographer Mark Harper clearly got much better views but he was probably working alone. Tanimbar Scrubfowl photo by Mark Harper from Bird Forum Opus

 

Our next destination was the Kai Islands about 250 km away to the north-west. Unfortunately we had to fly the 600 km back to Ambon and a similar distance back again. A bit like flying from London to Exeter via Aberdeen.

 

The next post will cover the rest of the trip with photos from Kai Kecil and Kai Besar, Haruku, Seram, Boano and of course Ambon.

 

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