Biodiversity loss has become a major source of concern in Southeast Asia, driven largely by deforestation and the large-scale conversion of land for Human use. Green Peafowl, Pavo muticus, are large, ground-dwelling Galliform Birds, formerly widespread in the dry forests of Southeast Asia. However, only about 16% of the forests they formerly occupied exists, which, combined with active hunting of these Birds for food, ornamental feathers, sale in the international pet trade, and simply to reduce their impact as agricultural pests on converted land, causing the species to be listed as Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species.
There are currently considered to be six remaining Green Peafowl strongholds on the Southeast Asian mainland, in southcentral Myanmar, northern and western Thailand, and northern and eastern Cambodia. There are thought to be about 30 000 individuals surviving in the wild, with a significant danger of several populations being wiped out.
The species has been the subject of a series of studies dedicated to understand the problems it faces, which include illegal hunting, logging, agricultural expansion, Cattle grazing, collection of nontimber forest products, and forest fires, and finding ways to meet its needs within multi-use landscapes.
Cambodia currently contains about 70 000 km² of protected land, spread across more than 50 different protected areas. This land is divided into four categories, strict protection core zones, conservation zones, sustainable use zones, and community use zones, the latter predominately being comprised of Human settlements and agricultural lands. This system aims to balance the needs of local communities with the ecological integrity of the protected areas.
Green Peafowl will occupy a range of habitats, including agricultural land, where it is widely viewed as an agricultural pest, leading to hunting and snaring both on farmland and in adjascent protected areas. This conflict with Human occupants of the same landscape presents a range of additional threats for the Peafowl, increasing the need for a specific conservation management plan for the species.
In a paper published in the journal Raffles Bulletin of Zoology on 1 April 2022 Chandra Tak of the Centre for Biodiversity Conservation at the Royal University of Phnom Penh, Rachel Crouthers of WWF-Cambodia, Niti Sukumal of the Conservation Ecology Program at King Mongkut’s University of Technology Thonburi, Sophea Chhin, also of the Centre for Biodiversity Conservation at the Royal University of Phnom Penh, and the Conservation Ecology Program at King Mongkut’s University of Technology Thonburi, and of Fauna & Flora International and the Department of Biodiversity at the Cambodian General Secretariat of National Council for Sustainable Development, present the results of a study which aimed to assess the population density of Green Peafowl within the Srepok Wildlife Sanctuary (formerly the Mondulkiri Protected Forest) in eastern Cambodia.
The Srepok Wildlife Sanctuary forms part of a wider transboundary socio-ecological landscape, the Eastern Plains Landscape, covering 14 000 km² of land in Cambodia and Vietnam, which consists of eight contiguous protected areas. The Srepok Wildlife Sanctuary comprises a core area, which covers 1756 km², where only government, community law enforcement officials, and researchers are legally permitted to enter and and an outer core covering 1994 km², comprising different land use types including areas of conservation value to areas that can be used for economic and subsistence purposes and/or support Human settlements.
The most common habitat in the Srepok Wildlife Sanctuary is a deciduous Diptocarp forest, dominated by the Saimise Sal Tree, Shorea obtusa, and the Gurjun Tree, Dipterocarpus tuberculatus, with smaller areas of mixed deciduous forest, semi evergreen forest, Bamboo and riverine forest. A number of rivers flow through the area year-round, with additional seasonal waterholes forming during the monsoon season, which lasts from May to October. During the dry season, both water scarcity and forest fires can be problems of wildlife and Human residents of the area.
Tak et al. surveyed the area by using listening stations to record the calling activities of male Green Peafowl, an approach which has been previously shown to be more efficient when surveying noisy but camouflaged Birds in dense forests. This was carried out during the dry season of 2015-16 (which is the mating season), with 80 listening posts set up in the area to the west of the Srepok River (the area to the east was deemed to be unsafe), covering an area of 1398 km² of the core area and 359 km² of the outer core.
The sampling stations were arranged in a grid pattern, separated by 4 km intervals east-to-west and 7 km intervals north-to-south. Observers were trained to recognise the call of the male Peafowl, and to accurateley record the distance and direction from which the call was coming, providing an approximate loaction for the Birds. Visual sightings were also recorded, but not integrated nto the dataset.
Peafowl were only observed in deciduous Diptocarp forest, semi-evergreen forest, dry woody shrublands, and non-forest areas. Evergreen forests and shrubby woodlands and other forest types were avoided.
Tak et al. recorded 438 Peafowl calls, from 167 listening posts. This led to an estimation of 1.08 calling males per km² in the outer core areas, and 0.56 calling males per km² in the inner core areas, and a total estimated population of between 897 and 1512 individuals.
The overwhelming majority of the Peafowl were recorded in deciduous Diptocarp forest (92.3% in the core area and 87.3% in the outer core), while non-forested areas were avoided, strongly supporting the hypothesis that forest-loss effects these Birds adveresly. The presence of seasonal waterholes had no apparent influence on Peafowl density, but the Birds were apparently more numerous close to both rivers and Human settlements.
The accurate monitoring of endangered species requires the ability to make accurate surveys of their population numbers and density. However, this can be difficult for species which live in dense forests or other cryptic environments. In such cases accurate counting by direct observation requires repeated surveys over several years, which is both costly and labour-intensive. Monitoring Birds using their vocalisations is therefore an increasingly popular option, which has been shown to work for a number of Bird groups, including Galiforms such as the Green Peafowl. However, sound-based surveys require vigorous training to enable those undertaking them to make accurate identifications, end estimates of distance and direction.
Tak et al.'s findings suggest that male Peafowl are present at greater densities in the Srepok Wildlife Sanctuary than they are in the nearby Keo Seima Wildlife Sanctuary, also in eastern Cambodia, and similar to that seen in the Siem Pang Wildlife Sanctuary in north-eastern Cambodia. This suggests that the type of land-cover available to the Peafowl is important; the Keo Seima Wildlife Sanctuary, although close to the Srepok Wildlife Sanctuary, is dominated by much denser forest types, whereas the Siem Pang Wildlife Sanctuary is predominantly covered by deciduous Diptocarp forest similar to that in the Srepok Wildlife Sanctuary.
No historic records exist that could be used to reliably estimate Green Peafowl population densities in undisturbed forests. However, the population densities of these Birds in Cambodia and Vietnam do seem to be consistently lower than those in northern Thailand. This is likely to be due to anthropogenic factors such as habitat modification, exploitation, Human-induced fires, and overgrazing, threats which are still present and likely to remain so until a species-specific management plan is put into place.
Birdlife International regards the Green Peafowl to be particularly prone to hunting, driven by demand for ornamental displays, meat consumption, and the pet trade, and during the period during which Tak et al.'s study was carried out, patrol and research teams removed more than 3000 snares which had been placed within the Srepok Wildlife Sanctuary. Blanket snaring was evident near water sources, and signs of shooting could also be observed throughout the reserve. The Green Peafowl is known to be vulnerable to these hunting techniques, as a large, ground-dwelling Bird prone to congregating in open spaces within woodlands. Tak et al. therefore recommend that law enforcement procedures in the area be adapted to specifically address the conservation needs of the species, if a rapid decline in population is to be avoided.
Residents of local villages frequently reported damage to crops by Green Peafowl, and admitted to using both snares and poison on farmland as was of reducing this. Green Peafowl were found at higher densities closer to villages, suggesting that they were attracted to the resources provided by Human settlements, and creating a higher risk of negative Human-Peafowl interactions in areas were forests are shrinking and the two species living closer together.
Tak et al. therefore recommend that future conservation plans for the species examine closely these negative interactions, and find ways to address these problems that take into account both the needs of the Peafowl and of Human populations in the region.
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