Birdernaturalist: Borneo Blog: Square Pegs and Round Holes

April 30, 2013

It perhaps would be of more interest to a psychologist than a biologist to know that this morning I heard Dull-capped Attila, Plain Wren, Red-billed Pied-Tanager, and Piratic Flycatcher. You see, I’m in Borneo, and those birds of the New World Tropics have no chance of occurring here. Yet time and again, I’d hear a new bird call or song, unseen in a dense thicket or from the top of an incredibly tall tree, and though a little odd, I’d find something in my brain to match up with it.

This was my first full day in the tropical elevations here, and everything is new to me. Everything. But I have this library of bird sounds in my head, probably numbering over 5000 separate vocalizations (some birds have many different call types), and I just can’t help but try to match what I know with what I'm hearing. Almost all of the birds I know are strictly American species, with a few vocalizations I can recall of European, African, and Australian birds (who can possibly forget the song of Eastern Whipbird?). If each and everyone one of these sounds in my head represents a square peg, every sound I heard this morning was a round hole. And I’m apparently quite good at putting square pegs in round holes if I heard a Dull-capped Attila this morning.

I’m at the Danum Valley Field Centre for only six full days, so I’m determined to make the most of my time. I was out before sunrise this morning and decided I would not go far from the dorm and open areas of the complex, thinking that it would be a good idea to familiarize myself with all the species that would be common in the disturbed habitats where they are easier to see. Then I would start on the forest interior species.

I started the day an hour and a half before sunrise in the kitchen with my Nescafe and met another traveler staying in the hostel, Belinda from Australia. This is her next-to-last morning, and she’s headed up the tree platform for sunrise. She’s here to see all kinds of rainforest nature but especially likes fascinating insects. I heard the first bird singing in the shrubby row next to the dorm well before sunrise, and I had no idea what this one is – a low, throaty “tyork, tyork, tyork...” repeated at a rate of about 2 per second. But it will be too dark for at least a half hour more before I have any hope of seeing what this is, so I moved on to more vocalizations beckoning from down the road.

I spent the rest of the morning on the entrance road, not making it more than about 500 meters from the reception office. Activity was high, and by noon it felt like I’d seen a hundred new birds. But I most definitely recorded more mystery sounds than identified seen birds. I got frustrated at some of the drab bulbuls (and it doesn’t help that the illustrations in the book don’t always match the text, nor the bird in real life), but those were more than made up by four species of gaudy and easy-to-see sunbirds in one small flowering tree overhanging the road. Van Hasselt's Sunbird is just stunning.

Here’s a view of the second growth along the road from a small observation tower just above the road.

I stepped off the road along a small shaded stream to try for birds in the undergrowth but all I found were these huge mayflies on territorial perches.

Later in the afternoon after what seems to be the daily rain shower I wandered up the Nature Trail near the dining hall, one of the few trails that they officially allow visitors on without having to hire a ranger guide, though this isn’t strictly enforced, and I think with my experience in tropical rainforests they seemed to have given me tacit permission to go where I wanted. The first section of this trail has a wooden boardwalk, then follows a stretch of the Segama River, here a particularly nice view. That's mostly primary rainforest on the other side of the river.

This part of the forest is partly disturbed, but some original trees and their ancient vines still live here.

A terrestrial orchid was particularly common here. It looked like it should be fragrant, but at least in the afternoon there was no scent.

And here I saw my first leech crawling up my pants, duly flicked off. Looking around, I was able to spot some on the tips of leaves next to the trail. They sense the infrared radiation coming from passing mammals and birds and reach out or drop to the ground and inch their way to the potential host.

Maybe more menacing looking to some, but most certainly completely harmless in contrast to the leeches was this orb weaver with some amazing protrusions on its body. The genus is probably Gasteracantha which translates to stomach-spine.

Insects were attracted to the lights at the dining hall as well as by the dorms. This most amazing moth had me fooled for a bit, thinking it was a large planthopper. It has a very muscular body and very strangely-shaped antennae. I’d wouldn’t be surprised if this belongs to a family not found in the New World – everything about it seemed so utterly foreign to me.