Poor genetic diversity bane for last surviving population of Kashmir red deer
doi:10.1038/nindia.2015.35 Published online 23 March 2015
Scientists studying the last surviving species of hangul red deer in the Indian subcontinent have found that their current population of a little above 200 in the Jammu and Kashmir state of India shows relatively low genetic diversity as compared to other red deer populations of the world1. This, they say, makes them a truly precarious species and calls for a rethink in ongoing conservation efforts.
The hangul — or Kashmir red deer (Cervus elaphus hanglu) — has long been at the centre of conservation efforts as it is the only subspecies of red deer in the Indian subcontinent and endemic to the state of Jammu and Kashmir. The study of this Kashmir stag’s genetic diversity by scientists from the Wildlife Institue of India (WII), Dehradun, also points that regardless of historical mishaps, the hangul population has sustained a sufficient number of effective breeders. The population seems to have an inherent genetic potential to bounce back with proper law enforcement and habitat quality enhancement.
The genetic diversity study supports a previous analysis2 of a population of Chinese red deer that bridged the gap in the understanding of divergence, evolution and dispersal of red deer from South East Asia to Europe and North America.
The WII researchers have resolved the hangul’s phylogenetic status and delineated its taxonomic boundaries among other red deer subspecies of the world. The scientists collected DNA samples from shed pneumatic hairs of hangul in the Dachigam National Park near Srinagar. DNA analysis revealed that hangul were clustered in the Central Asian Tarim group and were genetically closer to Bactrian deer than Yarkand deer found in this region.
Trends indicated ancestral movement of deer between the Tarim and Western populations. However, the Tarim group is geographically closer to the Eastern population. Similar studies have also been carried out recently by another group of scientists on the tissue and blood samples of hangul to corroborate this closer resemblance of the deer’s lineage to Bactrian and Yarkand deer than the European.
“Regardless of the historical consequences and mishaps, the hangul population sustained a sufficient number of effective breeders and seems to have an inherent genetic potential to bounce back to its historic numbers if proper protection, law enforcement and habitat quality enhancement is imposed,” says lead researcher Mukesh Thakur from the Wildlife Institute of India, Dehradun.
The hangul population has experienced several constraints in the past due to environmental and anthropogenic pressures. These have negatively influenced the population, resulted in severe decline in numbers and restricted its distribution range. Historically, the hangul occupied fairly large area of Western ranges of Himalayas comprising Kashmir, Chenab valley and some parts of Chamba valley of Himachal Pradesh. Now it is largely confined to the Dachigam landscape spanning over an area of around 1000 square kilometres including the protected areas of Dachigam National Park.
The hangul population has shown noteworthy fluctuation in the past few decades. According to the researchers, the population was about 3,000 to 5,000 in the1900s. It dramatically reduced to 700 by 1987 due to unknown reasons, then plummeted to 120 by 1994. Stringent conservation efforts had increased the hangul population to 375 by 2002. This, however, declined next year to 212. The most recent population size was estimated to be somewhere around 218 in 2011. “The decreasing trend in hangul population and ever-increasing threats necessitated this genetic analysis,” Thakur says.
The researchers say that rapidly changing land use in the Dachigam landscape has led to land fragmentation affecting deer corridors and restricted animal movement, which is crucial for maintaining genetic diversity and gene flow. The scientists emphasise the need to map, protect and enrich important forest patches that are potential hangul habitats in Dachigam. They say that conservation breeding and reintroduction should be done only after strengthening the in-situ conservation and management efforts.
Khursheed Ahmad, a wildlife scientist from the Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, has been monitoring a long-term research project on hangul movement patterns using GPS satellite collars in Dachigam. He says the project, funded by the India’s ministry of environment and forests, had collared one male hangul for the first time in 2013 and is hoping to collar 4 to 6 more hangul this year.
Ahmad says the decline in hangul population could be reversed by controlling factors responsible for fawn mortality, grazing pressure, control of pariah or domestic dog population in Dachigam and discontinuing the release of leopards in the area. “There is an urgent requirement to initiate a conservation breeding programme to augment hangul population in the wild.”
Besides, some isolated areas outside the Dachigam National Park, where relic populations are found, could become potential sites for new breeding programmes and provide some ideal corridors for the hangul to disperse, Ahmad says.
The hangul is listed under Schedule-I of the Indian Wildlife (Protection) Act, 1972 and Jammu & Kashmir (J&K) Wildlife (Protection) Act, 1978 and is one among the top 15 species that receives high conservation priority by the Indian government.
However, the International Union for Conservation of Nature (IUCN) has not accorded any special status to this subspecies of red deer and has listed it as having ‘least concern’ along with the other red deer subspecies of the world. The scientists strongly advocate that IUCN confer a conservation status to hangul distinct from other red deer subspecies of the world to draw more attention from national and international bodies.
1. Mukesh et al. Pragmatic perspective on conservation genetics and demographic history of the last surviving population of Kashmir red deer (Cervus elaphus hanglu) in India. PLoS One (2015) doi: 10.1371/journal.pone.0117069