Thriving in Thin Air: Pikas of the Himalayan Talus

Lekhram Singh Rawat, a Gaddi shepherd, was one of the victims of a raid by pikas. His camp, at an altitude of 4,100 m happened to be near a perfect habitat patch for Royle’s pikas (Ochotona roylei). It was an extensive talus slope, (a slope with abundant rocks and boulders), near the summer hamlet of Zingzingbar, on the Manali-Leh highway in Lahaul, Himachal Pradesh. During the day, when Lekhram and his two associates were away on higher slopes grazing their flock of sheep and goats, pikas apparently visited the camp and surveyed their stock of grains, kept in gunny bags.

“Yeh zahbra ka kam hain…” (this is the work of pikas) Lekhram tells me, “…woh beena-poonch-ka chuha bohot khatarnaak hota hain” (that tailless rat, is very dangerous). Such was my field introduction to pikas in June 2012. However, despite walking through the nearby talus, the pikas eluded me.

Pikas are among the highest dwelling mammals in the world, belonging to the order Lagomorpha and the family Ochotonidae (same order as hares and rabbits but different family). They resemble rabbits, but have short rounded ears, and no external tail. Grasses and herbs are their main food.

Pikas and marmots are considered ecological engineers. They play a key role in the vegetation dynamics of the high-altitude ecosystems they occupy. Pikas are also important prey for medium- to small-sized carnivores, such as red foxes, weasels, and martens, and raptors such as the golden eagle.

Pikas occur in Eurasia and North America. Research suggests that pikas originated during the Oligocene period (approximately 34-23 million years ago) in Asia. They then expanded gradually throughout the Eurasian landmass and subsequently moved into North America, across the Bering Land Bridge during the Pleistocene era. It’s like the pikas followed the retreating ice sheets and snowline from the last Ice Age, to colonise, and establish populations in suitable habitat patches, similar to many other species that currently inhabit the mountains of Central and South Asia.

Reportedly, there are 28-32 species of pika globally, only a remnant of the 20 genera that once roamed the planet. Some of the existing species of pika are rock-dwelling, while others are burrow dwelling. Some are territorial and social, with distinct divisions of roles for individuals in a colony, like forage collection and vigilance. Other species are asocial, leading solitary lives outside the breeding season.

In India, at least seven species of pika have been reported, generally occurring at altitudes between 2,500 m and 6,000 m. They inhabit alpine slopes with abundant rocks and boulders (taluses). Pikas may also inhabit human-made structures like boundary walls made of boulders, around agricultural fields, or the walls of livestock pens. It was in this kind of human-made habitat, that I first sighted this amazingly cute animal.

While surveying the snow leopard and its prey species across Kinnaur, Lahaul, Spiti, and Chamba districts during 2012, I was in Kibber by early July. The agricultural fields were filled with green pea and barley, an oasis amidst the cold desert, the prized annual crops for the hardy villagers. During the late afternoon, the fields of crops would glow and sway under Trans-Himalayan winds that swept through the area.

A colony of Royle’s pikas was residing in the walls around the agriculture fields of Kibber, which were actually built to prevent blue sheep from entering and foraging on crops. It’s here that some pikas found their shelter and food. A few villagers suffered losses of green pea and barley. But they were tolerant of the minor loss compared to the mass foraging by wild blue sheep herds.

Whenever I got the opportunity, in between large mammal surveys, I walked around Kibber village and observed the numerous pika colonies. Northeast of Kibber is a steep slope leading up to the Chomaling ridge. Amidst a slope strewn with rocks and boulders is a ruin of an old chhorten (Buddhist stupa). Himalayan woolly hare, pikas, and voles are abundant on this slope. One evening while walking down from Chomaling ridge towards the village, I observed some movement on the slope. A red fox was on the prowl, stalking a woolly hare. For 10-15 minutes the hare eluded the fox effectively by hopping from one Caragana bush to another. Unable to outsmart the hare and negotiate with the thorny Caragana, the fox left the hare alone and headed for the talus. The talus had come alive by now with movements of Royle’s pikas. The fox poked repeatedly, almost frantically, at the base of the rocks and boulders to get hold of a pika. But the little pikas were well protected by the rocks, thanks to their small size. By then the hare had come out of its impregnable Caragana shield, and was sitting in the open. The fox got drawn to the hare again, only to stand perplexed next to a Caragana, as the hare disappeared into the bush again, in the blink of an eye. It appeared as if the hare and pikas were engaged in complementary strategies, diverting the attention of their common predator.

Chandra Tal in the neighbouring Lahaul sub-division provides another wonderful habitat for Royle’s pikas. While surveying the desolate upper Chandra Valley, the survey team and I were resting at one of the numerous camps of Gaddi shepherds. Nearby was a talus, and some movement among the rocks and boulders drew my attention. There were at least 12 pikas foraging. After a while, 10 of them disappeared, and only two remained outdoors. After foraging, they engaged in playful behaviour. One would sit on a rock, the other would chase around it and topple, and the antics would be repeated over and over. At times the two would just sit tight, as if waiting for something, and then suddenly resume play again. Even after seven years, this post-foraging playful behaviour I witnessed remains one of the most pleasant memories of my field days in the Himalayas.

Ladakh is another key region for pikas. In addition to Royle’s pika, Ladakh is inhabited by the Ladakh pika, Nubra pika, large-eared pika, and plateau pika. During July-August 2017, I was fortunate to join a team of experts and scientists along with the legendary wildlife biologist Dr. George Schaller for a rapid survey of Trans-Himalayan wildlife: wolf, snow leopard, lynx, Pallas’s cat, kiang, Tibetan argali, Tibetan gazelle, Asiatic ibex, and bharal.

After surveying large parts of Sham Valley and Gya-Miru Valley, we were in Changthang, camping beside the Zurser River in the Hanle-Kalak Tar Tar region. One morning while observing hill pigeons and marmots on a riverside pasture, a fast-swimming creature in the river caught my attention. After a lengthy struggle against the current, the creature ultimately surfaced, completely exhausted. It was a plateau pika (Ochotona curzoniae). The fellow, probably numb by then, basked for nearly 15 minutes in the weak early morning sun. It was breathing heavily, a vapour rising off its completely wet fur. Then the pika rapidly moved towards me, and stopped right near my feet. I took some time to feel comfortable with this unexpected proximity, but I couldn’t take my eyes off this awesome swimmer. Plateau pikas are a social species, but this individual seemed clearly to be indulging in extreme solitary adventures.

The adaptability of pikas is astounding. As shown by research, they undergo non-shivering thermogenesis to avoid freezing, and hence need to feed throughout the year. And with increasing altitude pikas can convert white adipose tissue to brown adipose tissue, aiding in warmth and metabolism. In an environment where large bodied animals such as the brown bear must hibernate, these little mouse-hare like animals remain active through the lengthy, bitter cold winters, even under deep snow cover. It has been fascinating for me to observe how they live in rock and boulder walls and roadside rock debris, or even swim across a raging river.

However, due to their relatively narrow range of altitude and temperature tolerance, pikas globally, and especially the species in the Himalayas, are at risk from the impacts of climate change. Probably the biggest threat is the fluctuating temperatures in their habitats, and the cascading changes in vegetation composition and abundance due to variation in precipitation. As snowfall and rainfall become less predictable in the Himalayas, the soil moisture, nutrient content, vegetation regeneration, diversity, and productivity of vegetation are expected to vary.

Taluses are often considered wasteland. Rocks and boulders are indiscriminately picked up in large volumes for construction purposes, displacing pika colonies, perhaps even killing them. On very rare occasions pikas may be poisoned as well, since they forage on crops and are believed to eat away vegetation in pastures thereby inadvertently competing with domestic livestock.

Colonising and surviving in the highest and coldest places on Earth isn’t the most difficult task species of pikas have accomplished. They now have another, perhaps much steeper uphill task, of combating persecution and the changes wrought by global warming.