–Text by Anand Krishnan; Images by Chaitanya Deshpande (CD) and Vaibhhav Sinha (VS)
(This is the second of the two-part story on birds and natural history of Cambodia. Take it away Anand!)
Cambodia’s Northern Plains harbor one of the largest remaining expanses of dry deciduous dipterocarp forest in Southeast Asia, and this habitat has been identified as crucial to the conservation and survival of a number of species. A two-day visit to this forest (under the auspices of the Sam Veasna Centre) was the highlight of our trip to Cambodia. The village of Tmatboey in Preah Vihear province is one of several places where conservation organizations are engaging with local communities to preserve these unique forests (and some patches of riparian forest associated with them). Formerly home to a diverse megafauna, including elephants, gaur, banteng, Eld’s deer and Cambodia’s national animal, the kouprey, mammalian diversity in these forests has declined considerably in recent years. The kouprey has not been seen in decades, and may now be extinct; Sam Veasna, after whom the centre takes its name, passed away in 1999 after contracting malaria searching for this rare wild ox. The mammals kept the forests open by grazing the understory (along with, of course, seasonal fires), and maintained wallowing waterholes (known as trapaeng in Khmer). Their absence (the classical ‘empty forest’ syndrome) means that this function is now taken over by livestock, and by active management of the forest. However, in spite of the relative lack of mammalian diversity, the remoteness of these forests means that bird diversity is high. Three species of vultures, now critically endangered thanks to colossal population declines in India, maintain small yet stable populations in these forests, along with the endangered Green Peafowl and White-winged Duck, now very rare elsewhere (we did not see these around Tmatboey, although they may be found further north). The relatively open, dry canopy hosts a great diversity of owls, woodpeckers, parakeets, raptors and a host of smaller birds, many of which exhibit very interesting distributions which I shall explore in detail in subsequent paragraphs. In addition, I will discuss at length the flagship birds and conservation symbols of these forests, the Giant and White-shouldered Ibis, two large birds with distinctly curved bills that are critically dependent on trapaeng for foraging. These two bird species are among the rarest in the world, having declined to near-extinction with populations in the low hundreds; these forests are their last refuge in the world, having survived here thanks to their remoteness and protection by local communities.
The first thing that strikes a visitor to these beautiful forests is the terrain. Sunlight filters through the open canopy, which even in the cooler months of the year, can get quite warm. These deciduous forests are rich in leaf litter, and the understory is quite grassy and overgrown in places, with distinct burnt patches. Although the more open regions are relatively easy to negotiate, there are places where one must literally bend the grass to one’s own will (and keep an eye out for branches!). If one is as inept at navigating terrain as yours truly, many hilarious incidents involving shoes flying into the undergrowth may result, to the eternal amusement of one’s travel companions. The villagers of Tmatboey, who guide visitors through these forests, thread their way through the jungle with practiced ease, one which a city-bred Indian emulates with all the grace of Humpty-Dumpty. Chinese Francolin call loudly from deep within grassy recesses, and the occasional Blue-breasted quail may flush explosively at one’s very feet. Grasshoppers, butterflies and other insects are very much in evidence, particularly during the warmer portions of the day, supporting good numbers of Burmese Shrikes, Common Woodshrikes, Cuckooshrikes and minivets, bulbuls and rollers. Spotted and Red-collared doves are very much in evidence, and the calls of Lineated and Coppersmith Barbets are omnipresent. Parties of the striking Chestnut-capped Babbler may be observed threading their way through the grass, and the calls of Brown, Rufescent and Grey-breasted Prinias, together with Dark-necked Tailorbirds, are frequently heard. Overhead, one might spy a soaring Lesser Adjutant (and possibly the Woolly-necked Stork, although we did not see one), and Rufous-winged Buzzards perch on exposed treetops. The lodge at Tmatboey (running entirely on solar power) is frequently visited by a troop of Red-billed Blue Magpies, in India a quintessentially Himalayan species that here makes its home in these dry forests. The distributions of birds here are a distinct melting pot of widespread Asian species, uniquely Indochinese species (such as the Indochinese Cuckooshrike and the gorgeous Hainan Blue Flycatcher), birds restricted mainly to drier habitats in the Burma-Indochina region (e.g. the francolin), and some largely Sundaic (Malayan) birds that just extend into the region, creating a unique fauna, some examples of which I shall discuss in following paragraphs.
The diversity of insects within these forests additionally supports several curious birds of prey, including the Collared Falconet, one of the smallest of raptors. This tiny, elegant bird, barely larger than a sparrow, perches out on exposed snags, where its size renders it relatively inconspicuous, sallying out to capture a passing insect, which is then rapidly dismembered and eaten. They may be quite territorial; my first encounter with one in Manas, Assam involved a bird taking a strong dislike to the back of my head! The slightly larger White-rumped Pygmy-Falcon is one of those species uniquely found in these dry forests, and is a major attraction for visiting birders. Found only in Myanmar and Indochina’s dry forests, this bird is a member of a curious genus of falcons; the only other pygmy-falcon inhabits Sub-Saharan Africa! The sexes differ in color, the males with a all-white head, while the females possess a beautiful rufous-red cap. They perch on exposed treetops, uttering their peculiar calls and flicking their long tails as they do so. Across the exposed tree-trunks, some of which are hollowed out by fire, a multitude of woodpeckers hop about in search of prey. In these open forests, they are a highly visible component of the bird diversity, and a diverse community exist here. On our trip, we observed six species, including the Freckle-breasted, Yellow-fronted, Grey-capped Pygmy and Greater Flameback Woodpeckers. The beautiful Black-headed Green Woodpecker, like the Pygmy-Falcon, is confined to dry deciduous forests from Myanmar to Indochina, and territorial pairs of these species may be seen climbing the tree-trunks in search of food. The sixth woodpecker we observed, the huge Great Slaty Woodpecker, is the largest extant woodpecker on earth, measuring over 50 cm long. For such a large bird (and one with such distinct, far-carrying vocalizations), it is remarkably difficult to observe. The bird we saw was very shy, always keeping to thick, leafy regions of tall trees, and always keeping the tree-trunk between it and the observer. Slipping to a neighbouring tree unnoticed, it would only betray its presence by gliding off into the trees like a grey ghost one final time.
These dry forests are also home to a diversity of owls, whose day-roosts are typically known to the villagers, rendering them much easier to locate than at night. These owls range from tiny scops-owls, Spotted and Asian Barred Owlets to larger ones. The Spotted Wood-Owl (which we did not see) may be seen in several areas here; this is one of those species mentioned earlier, which is found largely in the Malay region but extends northward into Indochina. It overlaps in many areas with the related Brown Wood-Owl, a species we were able to observe at a day-roost. These owls are strictly nocturnal, and their eerie cries at night are associated with superstition in some parts of the world; an owl calling is thought to be an ill-portent and a harbinger of terrible events. One of the more unique owls found here is the widespread Brown Fish-Owl; this genus of owls are known for their unfeathered legs and their habit of perching close to waterbodies, where they may feed on fish, frogs and other aquatic animals. Their large size, together with the pair of ear-tufts on top of their heads, gives them a singular appearance, and hollowed-out trees are perfect places for roosting. Woe betide the owl that is located by diurnal birds, however, for these predators are then mobbed and harassed by groups of smaller birds until they relocate to a more secluded roost site. In the evenings around burnt-over clearings in the forest, one may also hear the peculiar metallic screech of the Savanna Nightjar, and if lucky, see one flying in search of insects with its distinctive long, pointed wings. During the day, however, they roost on logs or on the ground, merging with their surroundings so as to be invisible to all but the practiced eye.
In any Asian deciduous forest or woodland, parakeets are an almost constant feature of the fauna, where populations have escaped relentless trapping for the cage-bird trade. Healthy numbers of Alexandrine and Red-breasted parakeets remain around Angkor Wat, and the famed temple of Ta Prohm hosts mating pairs and roving flocks of both birds in abundance. The unwitting tourist is well-advised to keep an eye to the sky, in case a parakeet decides to answer the call of nature overhead! Around Tmatboey, both these species are handily surpassed in abundance by the gorgeous Blossom-headed or Roseate Parakeet. Flocks of these birds may be observed frequently here, close relatives of the Indian Plum-headed Parakeet. They differ from the latter primarily in the male’s head being rose-pink and violet (as opposed to deep-red and violet in the Plum-headed Parakeet), and in their call, which is distinctly harsher and more grating than their Indian counterpart. As mentioned earlier, the flagship species of the region for conservation purposes are the two threatened ibis, and while birding the jungles, one is always keeping an ear open for their distinctive cries. There are two ways in which one might search for these species: by concealing oneself near a roosting tree around sunrise or sunset, or by looking for them around feeding areas. Both species are extremely shy and wary, flying off into the forest at the slightest disturbance, and great care must therefore be taken not to disturb them. On our first evening in Tmatboey, we heard, by the light of the setting sun, the eerie screams of a pair of White-shouldered Ibis flying in to roost, and managed to find one of them perched in a bare tree for an extended period, periodically uttering its ethereal shrieks. This bird is an Eastern counterpart of the Indian Black Ibis, with an elegant sky-blue patch of bare skin on the nape and striking white shoulder-patches. Although the Indian bird is still common in many places, the White-shouldered Ibis has disappeared from Myanmar and Thailand, and all but disappeared from Borneo, with only sporadic sightings of tiny numbers recently reported in Laos and Vietnam. At one point referred to as Asia’s most threatened waterbird, numbers in Cambodia were thought to be under 100 birds until several important populations were identified in these dry forests. Conservation action is trying to protect the largest of these known populations, to conserve the last few hundred or so birds remaining, and nest monitoring at Tmatboey aims to improve breeding success.
Nest monitoring is also critical in the conservation of the Giant Ibis, the other threatened ibis in the region and one of the world’s rarest birds. This huge ibis, over a metre long with a large, downcurved bill and featherless wrinkled head, was, even a century ago, considered one of the region’s rarest birds. It is now extinct in Thailand, and only irregular dispersers from Cambodia may occasionally turn up in Laos or Vietnam, leaving almost the entire population in northern and eastern Cambodia. Here, too, the bird was not seen for almost 30 years, and in the early 2000s, was practically unknown in the wild. Extensive fieldwork since then suggests the population may be as low as 200 individuals. Territorial pairs issue loud trumpeting duets at first light before flying off to feed, and although this call may be audible for over a kilometre, the birds are shy and difficult to find. Our quest for the Giant Ibis involved a pre-dawn jaunt to the forest, and following the distant bugling of a pair through near-darkness, through thick grass, scratched by thorns and across dried riverbeds. The experience of hearing these bizarre trumpeting calls in the silence of the forest has to rank as one of the most atmospheric experiences of any trip to Cambodia. After over an hour of following the birds (and wondering whether we were any closer to them!), we had paused to listen for their calls, when suddenly a pair flew across a clearing in front of us, circling around in a wide arc to disappear into the forest. About a hundred metres further down the path, we relocated the pair perched on adjacent bare trees, and watched them for over a half hour from a suitable hiding place as they perched, preened, and honked their sonorous duets before flying off to feed. The protection of populations around Tmatboey has resulted in the stabilization of local numbers, and it is to be hoped that nest protection schemes and habitat preservation will ensure the survival of this spectacular denizen of the dry forests.
The Kulen Promtep wildlife sanctuary, of which Tmatboey is a part, also preserves areas of riverine forests along tributaries of the Mekong, and these forests are home to a distinctly different fauna from the dry deciduous forests. It is possible to observe otters along these river channels, and Common and Stork-billed Kingfishers perch on exposed perches. Fruiting trees along the river host a range of frugivorous birds, the largest of which is the charismatic Oriental Pied Hornbill. Green Imperial Pigeons fly across the river in good numbers, and Thick-billed Green Pigeons may be observed as well, and if one is lucky, the rare Pale-capped Wood Pigeon (we did not see one on our morning there). Trees on either side of the river host a range of small insectivorous birds, such as the Greater Racquet-tailed Drongo, Swinhoe’s minivet, Asian Brown and Blyth’s Paradise Flycatchers, Sooty-headed, Streak-eared and Stripe-throated Bulbuls, Brown-throated, Olive-backed, Purple and the gorgeous Van Hasselt’s sunbird, and many others. From the underbrush, the calles of the Pin-Striped Tit-Babbler and the Dark-necked Tailorbird are frequently heard, and here, too, the call of the Great Slaty Woodpecker may be heard at intervals. We heard the calls of the Racquet-tailed treepie, a bird with a curious distribution, being found in Indochina and in Java and Bali, but not in intervening areas. These riverine forests are particularly interesting in possessing a number of largely Malayan birds whose range extends into Indochina along these riverine forests. The Brown-throated sunbird is one such, but we additionally heard the distinctive calls of the Orange-breasted Trogon and the Banded Broadbill, although they remained hidden from view.
The wilds of Cambodia offer an opportunity to stray from the beaten path, away from the tourist hordes at the famed Angkor historical site, and obtain a perspective on a unique part of the country that few people ever see. The forests of Cambodia’s north are some of the last of their kind, and the expansion of logging now greatly threatens their survival. Their spectacular birds represent but a fraction of the country’s biodiversity. The varied forests of Mondulkiri, home to the Green Peafowl, the Indochinese endemics Red-vented Barbet and Orange-necked Partridge, as well as a range of primates including gibbons and douc-langurs, is also home to several conservation programs aimed at protecting its stunning habitats with the help of local communities. The montane forests of the Cardamom mountains host huge hornbills, shy, colorful pittas, the Cambodian hill-partridge and one of the last wild populations of the Siamese crocodile. A visit to these environments would offer a dramatically different experience of wildlife from those discussed in this essay, and I greatly hope to someday make it back to Cambodia to explore (and write about!) them all.