Researchers at the National Centre for Biological Sciences (NCBS), Bengaluru have identified a new species of Pika, high up in the Sikkim Himalayas. In their recently published study, the group, including Dr Uma Ramakrishnan and her collaborators, probed the genetic origins of the little mammal, only to discover an entirely new lineage, with a unique evolutionary past. Their work is expected to pave the way for a deeper understanding of biodiversity in the Himalayan region.

Regions such as the Himalayas are well-known for their biodiversity. Such habitats often have an abundance of species owing to factors such as topology and climate. Nevertheless, the discovery of a new mammalian species in this region highlights the fact that there is still much to learn about the biota of this unique landscape and that additional studies may lead to more such discoveries.

Pikas are members of the rabbit family and live either high up in the mountains or in cold (temperate) places as they are highly cold-adapted. This feature of their biology makes them sensitive to habitat loss from increasing global temperature. The majority of Pika species described to date are of Asian origin. “Pikas are particularly important because they are considered indicators of climate change based on studies in North America. In order to monitor the impact of climate change on species in the Himalayas, we must first know what these species are. Asia is considered to be a hotspot for Pika species, and yet our knowledge of Asian Pikas is limited. So limited, that in 2016, we have discovered a new species in the Sikkim Himalayas!”, says Nishma Dahal, the first author of the paper. The new species has been named Ochotona sikimaria.

Dahal used genetic tools in order to understand the origin and evolution of the Pika species commonly found in the Sikkim Himalayas and worked with Pika droppings to obtain DNA samples for testing. By comparing DNA sequences from these samples with those of commonly known Pika sequences from across the world, she concluded that there were clear differences.

The researchers decided to use additional approaches to build on these observations. Gaining a deeper understanding of the evolutionary history of this species required genetic data from its close relatives: all of whom live in China. Thanks to musuem collections and collaborators in the US, the NCBS team were able to acquire data for one sister species. Collaborations built with a team from China allowed assessing a second sister species. In addition, as the team wished compare morphometric data between species, collaborators from a museum in Russia were also involved in this study. It took Ramakrishnan and Dahal a two year journey to build the required collaborations with researchers from the Chinese Academy of Sciences, Zoological Museum of Moscow and Stanford University. They chose to compare the Sikkim Pika to its close relatives in China. This analysis confirmed the fact that the new species is indeed distinct and not merely a subspecies of the Moupin Pika, as was previously believed. Multiple lines of evidence, including genetics, ecology and morphometrics, were used clarify the origins of the Sikkim Pika and to establish that it is indeed a distinct species.

The new species appears limited to the Sikkim region. The NCBS team have also scouted other Himalayan regions of Arunachal Pradesh, Central Nepal (Annapurna and Langtang), Ladakh and Spiti without success. Surveys in Bhutan, neighboring regions of eastern Nepal and China are are also being considered. 

But all is not well for this small mammal. “Pikas are among the most fascinating mammalian species. Unlike other mammalian species inhabiting such harsh environments, Pikas do not hibernate. They prepare for winter by collecting and storing hay piles for their winter food. We must investigate their vulnerability to increasing global temperature, and to do so we must have a better understanding of their ecology and population dynamics. Such information is lacking for Asian Pikas.” says Dahal, a native of Sikkim and currently in the final stages of her PhD research at NCBS on Himalayan Pikas.

“Pikas may seem like small an insignificant animals, but they are ecosystem engineers, which means they modify and provide critical services to functioning ecosystems. They are unique components of the Himalayan high elevation ecosystem and we must ensure their survival. This will require scientific data that helps better understand their biology. The opportunity to work on Himalayan biodiversity has been amazing, and I have learned how little we know about our own species. ” says Uma Ramakrishnan, whose laboratory at NCBS led the study.