Today’s focus was the lower reaches of the Belait river, which we surveyed in a rather small boat. I was again joined by Kolbjorn, and as we set out, I couldn’t help but be reminded of the Lower Kinabatangan in Sabah.
The difference between them is that, while the forest on the Kinabatangan is now reduced to a narrow discontinuous fringe, the nipah and swamp forests bordering the Belait are extensive and intact. It was very strange therefore, to learn that there are no Proboscis Monkeys or Orang Utans, both apparently hunted out perhaps a hundred years ago.
We explored a few smaller creeks off the main river and those nearest the coast were lined by extensive stands of nipah.Nypa fruticans is the characteristic palm of tidally influenced rivers in South-east Asia. Where it grows it does so to the exclusion of almost every other plant, and it creates a somewhat sepulchral and forbidding atmosphere once you get into it. It has many traditional uses – from the fruit (sea coconut) to the fronds which are used as traditional ‘atap’ roofing material and as cigarette papers. Extensive stands of nipah are getting rarer in South-east Asia due to development of coastal riverbanks – Penang only has one river with Nipah still lining the banks, and this is being cleared presently to make way for small-scale industries.
Not many birds are at home in nipah, but Mangrove Blue Flycatchers are one of those that are. The orange extends all the way down to the vent, a rather obvious feature which is overlooked in almost all regional field guides. The Phillipps guide is more accurate than Myers on this one.
Kolbjorn and I were baffled for some time by a loud, tuneful babbler song which was unfamiliar to us. Recording and playing the call back brough immediate response, but the birds proved difficult to get a clear view of, partly due to our restricted movement in the small boat, and partly due to the birds’ habit of singing behind palm fronds! Even when we got glimpses – initially of a juvenile, there wasn’t much that was distinctive. Knowing that Abbott’s Babbler is virtually unknown in Borneo, the nearest I could come up with at the time was Horsfield’s, but somehow the loud, sustained song didn’t fit that species either. Only when I got back to my hotel and was able to compare my recordings with those on xenocanto and found this one of an Abbott’s Babbler at Sungai Wain, Kalimantan, was I able to identify it as Abbott’s Babbler – sounding very different from what I’m used to hearing in the Peninsula! I got a few very poor photos which confirm the id.
According to Myers, the race concreta, which is endemic to Borneo, the Matasiri and Belitung Islands, has only 21 confirmed records from Borneo, and none from Brunei, although I did find a 2009 record of two in Andulau Forest by Jeremy Moore. So, in terms of my Borneo list, this was a mega! Judging by the number of singing birds around, there seemed to be good numbers, so maybe this will become a place to visit for the Borneo 500 Club members!
Black-and red Broadbill nests were regular distractions along the main river bank.
I soon retreated back to the boat – the buttresses of this tree were the only firm footholds in the wet surface, and it was perilous in the extreme trying to take photos while balancing on one of these!
How a tree stays upright in swampy ground!
Other inhabitants of the swamps… we had to sneak slowly under this wasps’s nest. I think the local name for these is pingat-pingat. I’d been stung by them before and had no wish to repeat the experience!
Merijn and I came back to do the same trip after dark. The weirdest thing was the lack of insect noise! I can’t remember being in such silent forest after dark.
There must have been insects though, because there were frogs. I’ll have to get Ulmar/Merijn to remind me of the species name of this one. [Rough-sided Frog Hylarana glandulosa – thanks to Muin. If I remember rightly, I think it’s also called “Swamp Dog’ because of its bark-like call.]
Despite a few riverine specialist species we recorded, I got the feeling that we had only scratched the surface of this beautiful and virtually pristine habitat. The challenges of getting in there are extreme, but would certainly repay further visits by the determined!