The wild and wonderful calling of gibbons is a highlight of Thailand's rainforests.
This recording begins in the predawn, with frogs croaking from a streamside pool and the first birdsong carrying through the dense forest. The songs of bulbuls, laughing thrushes, scimitar babblers, and the heavy wingbeats of hornbills all contribute to a tropical ambience.
Eventually a group of gibbons appear, swinging acrobatically through the treetops. The males call loudly to advertise territory; their rich, expressive voices echoing through the forest. Later we hear several individuals calling to each other alternately over great distances.
"Documenting the songs of Gibbons was a priority during our field recording in Thailand."
"We heard their wonderful songs in many locations. However they are extremely loud, and getting the right balance of atmosphere and dynamics was not always easy. Sometimes they could be heard so far in the distance that the melodies of their songs were only hinted at. Other times they would be crashing around overhead. Khao Yai, where this recording was made, seemed to be just right, surrounding their voices in a rich forest ambience with a good diversity of birdsong."
"One morning, entering the rainforest in the dark before dawn to make these recordings, I came across a very fresh pile of elephant dung in the middle of the track. It had not been there the afternoon before. I continued walking cautiously, but it was rather unnerving."
00:00 - Predawn by a Rainforest Pool
We begin by a still streamside pool in the rainforest of Khao Yai National Park, just before first light.
I'm not sure of the identity of the frog species here, however it is possible that they are Banded Bullfrogs (Kaloula pulchra), judging by the call and their common occurrence at Khai Yai. Also to be heard is the two-note piping call of a Mountain Scops Owl (Otus spilocephalus), and the distant booming of a Greater Coucal (3:22, 4:00).
4:10 - First Light in the Gibbon Forest
The dawn chorus starts with numerous Grey-eyed Bulbuls (Iole propinqua) and the whine of tree cicadas. Great Hornbills (Buceros bicornis) can be heard far off, with their mighty "Roak, Roak.." calls (distantly at 4:40…, and one a little closer at 6:55…). Several Moustached Barbets (Megalaima incognita) begin calling with their piping "took-a-rook, took-a-rook, took-a-rook..." (7:50-9:15). Birds calling in the background include a band of White-crested Laughing Thrushes and a White-browed Scimitar Babbler, while a squirrel is heard briefly nearby, a short series of high-pitched squeaks (10:15)
11:16 - Birdsong of the Thai Rainforest
The scratchy, scolding calls of a Puff-throated Bulbul (Alophoixus pallidus) are heard from the undergrowth nearby (11:28…). The mellow three-syllable "woot-oo-whiaw" of a White-browed Scimitar Babbler (Pomatorhinus schisticeps) is heard closer now (left, 11:18…). A family of White-crested Laughing Thrushes (Garrulax leucolophus) call loudly nearby, a series of piping notes leading to a bubbly cacophony often given by several birds simultaneously (13:17…, 13:59…, 5.00-5.18...). Another Laughing Thrush species gives harsh, scolding calls (right; 12:13…). The distinctive wingbeats of a hornbill are heard overhead (16:37, 17:13 and gliding faintly; 18:25). In the background you can just hear the deep booming notes of a Mountain Pigeon (Duclua badia) (14:25, 14:36, 14:50…). Something(?) begins a series of unusual tapping sounds (~18:15, getting louder to 18:54…), it's likely to be a Racket-tailed Drongo, heard giving a song shortly after (18:56). Meanwhile, in the distance (~18:46…) are heard the cries of a Crested Serpent Eagle.
The first gibbon calls begin (18:31), before a disturbance of foliage in the treetops announces their presence overhead (22:16).
22:37 - Song of the White-handed Gibbon
Two male White-handed Gibbons (also known as Lar Gibbons, Hylobates lar) gradually begin their territorial song (23:45), while hornbills continue to fly overhead (23:01). The "chip, chip, chip" calls of a Common Tailorbird (orthotomus sutorius) come from nearby (24:16 - 25:00). In the background are "quaint!" calls from Puff-throated Bulbuls (right; 24:23, left; 28:03…). If you listen carefully, there is a curious up and down whistle, quite un-pigeon-like, of a Thick-billed Green Pigeon in the distance (31:30) and the far off drumming of a largish woodpecker (Yellownape?) (31:11, 31:22, 31:32…). A Coppersmith Barbet (Megalaima haemacephala), which usually gives a monotonously regular series of resonant "tonk" calls, here arranges them into a little skipping pattern (background, noticeable; 30:53…)
32:22 - Mid-morning Rainforest Ambience.
The bubbly, cheery calls of Black-crested Bulbuls (Pycnonotus melanicterus) have been audible for a while now (clearly; 31:29, 31:57…), along with some more Common Tailorbird calls (33:20…). The woodpecker continues drumming, and a Spotted Dove can be heard faintly (34:22…). Loud, raspy calls (34:45, 35:09..) are Puff-throated Bulbuls again, and a little later the quick, tinkling two-syllable "whi-tuu" and "whi-did" calls are Grey-eyed Bulbuls (noticeable; 36:25, 26:32, 37:05). A Plain Flowerpecker flies past giving sharp calls (37:16…, and later 39:16…), and those wonderful hornbill wings can be heard passing overhead (37:24 - 37:43). There is a good, clear Puff-throated Bulbul "quint!" (39:27, 39:34…). Laughing thrushes call intermittently to the right side in the latter part of the track.
41:36 - Laughing Thrushes and Shama
Tree cicadas begin calling again, and the white-crested laughing thrushes continue. The lovely song of a White-rumped Shama is heard from undergrowth nearby (41:37, 42:14, 42:25, 42:39…). In the background are Spotted Doves, Barbets, Puff-throated Bulbuls, a small woodpecker giving a rapid drum (42:00, 42:22, 42:37…), and a wild Red Jungle Fowl (45:12, 45:37). I think the high-pitched piping calls (from 46:03) come from a Three-striped Squirrel. Two Moustached Barbets begin calling (48:02)
50:39 - Antiphonal Gibbon Calls
Here several gibbons, likely from different family groups, call to define their territories. It is mid-morning, and also a time when females will join the singing. The prominent "Zee-ch-chit, ch-chit, ch-chit" heard almost throughout is, I believe, a Common Tailorbird, and later another Scimitar Babbler is heard again giving a piping, three-note whistle (58:58…). Various Bulbuls continue calling, plus the woodpecker, and there seem to be several small bird species around, possibly including Warblers and Prinias.