The study published in the journal Environmental Monitoring and Assessment has revealed that the suitable distribution areas for the sangai deer will be narrower and will be restricted to the central core zone of the protected area.

Unlike other national parks in India, Keibul Lamjao National Park is a 40 sq km patch comprising mainly of floating biomass (locally called phumdi) and water body, in the southern rim of the saucer-shaped Loktak Lake, a Ramsar wetland of international importance and the largest freshwater lake in northeast India. As per the 2016 census, the park is home to 260 sangai.

What study says

The study modelled and analysed the habitat suitability potential for the current scenario and projected the future scenarios of potential habitat suitability of the sangai in Keibul Lamjao National Park based on climatic conditions and topography of the region.

Carried out by Vicky Anand and others from the Department of Civil Engineering, National Institute of Technology Manipur, Imphal under the guidance of Bakimchandra Oinam, the study used two climate change scenarios or representative concentration pathway scenarios (representative concentration pathway 2.6 and representative concentration pathway 8.5) to create geographical distribution maps spinning to 2050 and 2070 and compared them to the current potential distribution map. The driving factors for the impacts are rainfall in the monsoon (wettest) months and isothermality.

“The study result indicates that the high suitability zones within the national park will decrease in terms of area (ie the spatial extent) and the high suitability zone will be limited to the central core zone of Keibul Lamjao National Park,” Bakimchandra Oinam told Mongabay-India. “Secondly, the high suitability zone will shift from the western periphery of Keibul Lamjao National Park towards the central region.”

Sangai or the Indian Eld’s deer is one of the three subspecies of Eld’s deer found in South and South-East Asia. It has adapted itself to a unique habitat of the floating meadows or phumdi at the national park, a marked difference from the other two, according to background information provided by the Wildlife Institute of India. The sangai is identified under the Ministry of Environment, Forest and Climate Change funded Endangered Species Recovery Programme that is executed by the Wildlife Institute of India.

Sangai is listed as “Endangered” in the International Union for Conservation of Nature Red List of Threatened Species and Schedule I of the Indian Wild Life (Protection) Act, 1972. Sangai is also included in Appendix 1 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.

The deer was thought to have gone extinct in 1951 until a remnant population was rediscovered in 1953 at the south-eastern fringe of Manipur’s Loktak lake in a survey conducted under the auspices of the IUCN.

Climate change

The Wildlife Institute of India had called for having a second home for the sangai as the present population at Keibul Lamjao National Park is a single, isolated population, and highlighted that the proposed reintroduction to a second site needs to be expedited.

Their report identified encroachments into the lake, changes in the lake’s hydrology, impacts of the Ithai barrage, excessive proliferation and thinning of the meadows, susceptibility of the deer to inbreeding depression as some of the major challenges to the conservation of sangai.

Poaching and death from disease are other factors affecting the sangai population and an appropriate protection strategy and disease-monitoring plan need to be developed and implemented to reduce mortality, the report said. Five sites were identified of which Pumlen Pat was considered as the most appropriate, but there were protests from locals.

The present study pointed out that isothermality and rainfall in the wettest months (monsoon season) are the two most important or significant climatic variables which influence the habitat of the sangai. Isothermality quantifies how long the day-to-night temperatures oscillate relative to the summer-to-winter (annual) oscillations.

The findings are linked to concerns raised by Anand and co-authors in a 2020 paper that highlighted a likely increase in both precipitation and temperature in the Manipur river basin which encompasses Loktak Lake and Keibul Lamjao National Park.

The study found a high risk of floods in the lower regions near Loktak Lake and landslides in the northern part of the basin but said there is “no major concern” about water scarcity in the coming decades in the Manipur river basin.

The Keibul Lamjao National Park has three hillocks and the 100 m to 200 m wide area called Thangbral-yangbi (locally) stretching from west to east is the only hard ground in the entire park. The rest of the area is covered by swampy phumdis.

These features provide suitable feeding, bedding, and breeding ground for the sangai. But flooding in the monsoon season increases the water level of Loktak Lake which adversely affects the swampy phumdis.

The three hillocks and the Thangbral-yangbi are the only hardgrounds in the entire park on which the deer can take rest and shelter especially during the heavy rains and floods, which makes the suitability zone very confined especially during monsoon, according to the authors.

The modelling results revealed that the area that has most suited to sheltering the sangai is decreasing, whereas the area not conducive to the sangai is increasing, especially in the northeastern zone of KLNP adjacent to the main water body of Loktak Lake which is of major concern.

The authors claim that the central zone of the Park, including the hillocks, is most suitable for the sangai, is consistent with the availability of thick phumdis and low anthropogenic disturbances in this region, she said. The central zone is the prime habitat, and a significant proportion of the sangai population inhabits the area.

“This study gives an excellent glimpse of the shrinking habitat of the rare and endangered sangai of Manipur,” Tuboi said. “The future predictions with the expected climate change scenario affirm the study by the Wildlife Institute of India that alternate actions such as relocation for the conservation of sangai are imperative. Such studies that can scientifically suggest appropriate habitats and predict future trends can guide decision-makers to manage this endangered population.”