Over a span of five decades, eight mammal species have become locally extinct in Keoladeo National Park in Bharatpur, a study has revealed. 

Many species of wild animals including tiger, leopard, blackbuck, smooth-coated otter, leopard cat, Indian fox and Hanuman langur have become locally extinct in Keoladeo National Park since 1966. This has substantially changed the mammalian diversity and the condition of the habitat, say researchers. 

Although blackbuck has become locally extinct and sambar density has significantly reduced, chital and nilgai as habitat generalists have increased in density in the last 25 years, which has contributed to an overall increase in the ungulate population in the park. This study was conducted jointly by the researchers of Salim Ali Centre for Ornithology and Natural History, Guru Gobind Singh Indraprastha University and Manipal University and published in the journal Current Science. 

The disappearance of many of these species can be attributed to continuous modifications of both terrestrial and wetland habitat. In the past few decades, the park has been facing degradation due to repeated droughts and threats from invasive species--Eichorrnia crassipes, Paspalam disticum and P. juliflora. Other reasons include logging and cattle grazing, the likelihood of toxic chemicals in the water from the catchment area, besides political pressures leading to irregular water supply, the study says. 

“Changes in habitat affect species richness, population abundance and distribution, thereby affecting the local distribution of the species around the world. Understanding the social behaviour and demography of the wild animals plays a major role in population monitoring and effective conservation planning,” says H.N. Kumara, one of the key members of the research team. In 1964, leopard was exterminated from the area but has recently been observed through camera-trap technique by the forest department.

Tigers have been reported twice from the area with first sighting in 1999 when a tigress ventured into the park but was later found dead. In 2010, a tiger came from Ranthambore National Park and stayed in the park for four months until it was relocated to Sariska tiger reserve. 

Keoladeo National Park is a world heritage site spread over a 29-square-km dynamic ecosystem with rich floral and faunal diversity. It was officially recognised as a protected bird sanctuary in 1971 and then a national park in the year 1981. After this, it was included in the UNESCO's World Heritage list in 1985. 

There are references to 43 mammalian species in Keoladeo, out of which 30 species are still present in the park. Keoladeo National Park, popularly known as a “bird paradise”, is also rich in flora and fauna, with more than 350 species of birds, 13 reptiles, seven amphibians, 40 fish and 375 species of angiosperms.

Apart from H.N. Kumara, Akriti Singh, Aditi Mukharjee and Sumit Dukia were also included in the research team. (India Science Wire)