Saturday, November 30, 2013

Desert Ice

Horses grazing in the pastures around Tost mountains in the Gobi desert

Of course life in deserts revolves around the oases and waterholes. Almost every animal and bird has to visit one of these for a drink. However, the cold deserts of the Trans-Himalayan region tend to be a little different. The animals here depend on the snow in winter and glacier and snow melts in summer for their water requirements.

Gobi desert

The Gobi desert in Mongolia is a weird mix of both! Summer temperatures here reach a maximum of 35 Degrees Celcius and winters freeze at 25 degrees below zero. Come summer, life revolves around waterholes and oases which are the only source of water. As winter approaches these sources of water freeze over and a new source of water is delivered: snow! Although most animals here are adapted to the a desert life, there little requirement for water is met through eating snow.

This year was different. I arrived in the Gobi on the 28th October. The autumn was giving way to winter. This year the winter was predicted to hit hard and hit early. But something didn't go as predicted. The snow never arrived. Well into November and all life still revolved around waterholes; some natural, others man-made. As the cold hardened the smaller and more exposed of the waterholes started to freeze. The few that still had water were attracting more and more visitors. Some of us decided to spend time at these waterholes and observe what came there during the day. We were not equipped to spend nights out in the cold so we ignore the nights.

Asiatic ibex searching for water

We picked a waterhole near our camp. It was a busy place. Right at first light a large herd of about forty ibex ware at it. This waterhole had started also started to freeze over but a small gap in the ice allowed them access to water. But a small opening meant that only one animal could drink at one time. There was a long waiting for the young and smaller ibex. They had to also maintain a vigil for wolves and snow leopards.

The birds had it tough too. Since the sun rise birds kept flocking in and out of the small valley where the waterhole is tucked in. They too took turns but it worked quicker for them. A flock of passerines or partridges would come in the sand next to the waterhole, a few quick bill fulls of water and they would fly off. I saw more species of birds at this water hole in day than what I had seen in two months of field work!

Chukar partridge

And just around mid-day it happened. A single medium sized bird flew into the valley and instead of heading to the waterhole, it perched about thirty meters from it on a boulder. It was dull grayish-brownish. Once it was on the boulder it was hard for me to see it clearly. A few minutes later three common redpolls (Carduelis flammea), a very small finch like bird, came and dived straight for the waterhole. And the mystery bird which was perched on the rock a little distance away dived after them but missed. The redpolls scattered away but the mystery bird had chosen its prey and kept close in hot pursuit. At first it was like a two fighter planes locked in combat. They flew fast and turned rapidly. Soon the smaller bird changed strategy. It tried to gain height over the bird in pursuit. Now they were just hovering at the same spot going higher and higher. It was like to choppers battling it out. As they moved higher in the sky their silluettes became smaller and just before they would disappear they smaller bird dived fast and disappear. The mystery bird returned to its perch. This time I got a better look and later identified it as the Northern shrike (Lanius excubitor). In the days that followed we often saw peregrine and saker falcons, golden eagles ambushing their prey at this waterhole.

Redpoll eating ice to get water

And one day without warning the waterhole froze over completely. We would see ibex come to it and turn back without quenching their thirst. A few days later a colleague found a healthy looking ibex female lying dead only a few meters from the frozen waterhole. There were no external injuries. Its health didn't suggest any disease either. It seemed like she had died of thirst. I was left wondering how far she had traveled in the hope of water. And then her hopes shattered so hard that she died right there, perhaps more out of disappointment than out of thirst.

Mongolian ground jay

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