Green peafowl (Pavo muticus) and banteng (Bos javanicus) sharing a grassland patch within the Dry Dipterocarp Forest of Huai Kha Khaeng Wildlife Sanctuary (Western Thailand). The presence of large herbivores is thought to be fundamental in maintaining the open understories preferred by green peafowls. Credit: N. Sukumal
Green peafowl male displaying to a passing by female Huai Kha Khaeng Wildlife Sanctuary. The area of the tail covered by “eye” has been suggested to represent male quality to receptive females. Credit: N. Sukumal
Female green peafowl nest in thicker understory, compare to where the species usually range, to limit predation. The clutch size for the species varies between 3 to 6 eggs. Credit: N. Sukumal
A group of green peafowl females foraging on a harvested rice field, where they feed primarily on the remaining rice, in the low intensity / multi crop patches landscape typical of the PweHla area, southern Shan State (Myanmar). Credit: N. Sukumal
Green peafowl roost on large trees to limit the impact of nocturnal predators. In an agricultural landscape, the presence of large trees helps maintaining a viable population despite their habitat has been degraded and natural forest is very limited. Credit: N. Sukumal
A peafowl’s depiction in a detail of Khmer narrative reliefs in the outer gallery of Angkor Wat (12th century), Cambodia. Credit: T. Savini
The tail feathers of green peafowl males are commonly used in religious ceremony over the region, as shown in this monastery in South Shan State (Myanmar). For this reason, in the area, monks play a very important role in the conservation of small peafowl population often found in crops surrounding monasteries. Credit: N. Sukumal
Assessing green peafowl long-term survival
Green peafowl (Pavo muticus), a charismatic large-bodied species categorized as Endangered since 2009, was once widely distributed over the dry forests of mainland Southeast Asia. In recent years, however, its population has drastically declined and is current heavily threatened over its range due to habitat degradation, habitat fragmentation and hunting.
Using the species’ historical (since 1874) and recent locations, its probability of occupancy over its entire range, indicates a drastic decline of its habitat now covering only 16% of its original range. This remaining habitat is mostly confined to small, isolated populations with only six potential strongholds, based on the presence of the largest patches of remaining suitable habitat. As the species’ status for each stronghold was unknown, extensive detailed surveys have been conducted over the past several years allowing us to confirm the presence of viable populations in each of them. The data are currently used to classify the status of each stronghold based on the conservation and management actions needed.
The main cause of habitat degradation is agricultural expansion which can either be highly intensive with large areas of monoculture, or low intensity subsistence with smaller multi-crop patches. Depending on the type, a different effect on peafowl survival has been estimated with the more heterogeneous habitat of low intensity agriculture being more favorable for the species. Extensive work has been, and is currently, carried out to assess such effects as well as investigating what crop types can favor the species. Results have shown that outside of natural areas, orchards and teak plantations are highly selected possibly due to their resemblance to the species’ natural habitat. From a management perspective those crops can be used in a fragmented landscape to potentially connect natural habitat fragments. Moreover, we are currently investigating how long it is needed for cleared land to recover to a level suitable for the species once agricultural lands are abandoned (i.e. shifting cultivation).
The use of agricultural landscapes by peafowl has, on several occasions, generated conflict with farmers and increased the threat to the species by domestic, free ranging dogs. The issues have been investigated at different sites to estimate the impact of these threats to the species, with particular focus on crop types and fragmentation levels of the adjacent remaining habitats.
Population Viability Analysis (PVA) predicts long-term population survival, extinction risk and associated threats within a specific environment or a specific site. Understanding this quantitatively, determining a Minimum Viable Population (MVP) size, is fundamental when evaluating the effectiveness of any implemented conservation/management decisions. These analytical methods take into account population growth parameters (i.e. initial population size, population growth rate, survival rate, productivity and predation rate) and determine how they are affected by environmental factors (i.e. habitat quality, disturbance level and protection level). With almost 15 years of research and monitoring of the species, and following the development of better analytical techniques, we are now able to conduct both PVAs and determine MVPs at a population level. We can also develop further demographic population analysis using sex and age structure to understand which of these factors is likely driving a population’s projected extinction or recovery.
The six potential strongholds remaining over the green peafowl range. [1] Bago Yoma range (central Myanmar); [2] Salawin area (northwest Thailand and southeast Myanmar), [3] Northern Thailand; [4] Western Forest Complex (western Thailand); [5] Dângrêk forested range (northeastern Thailand, southern Laos and northern Cambodia); [6] Eastern Dry Plains (eastern Cambodia and southern Vietnam)
Several green peafowl wild groups are found in the relative safety of monastery compounds in Shan State, Myanmar, where monks and villagers protected them due the important role they have in local cultures. Work closely with such monasteries and community has been part of our activities over the past decade. Credit: N. Sukumal, 2016