How do reindeer and Yakut horses cope with the harsh Siberian winter? They are ‘eternally tipsy’

Scientists find how the animals produce ethanol in winter as an anti-freeze giving them the survival spirit.

The animals are known for surviving, even thriving, in the most extreme cold temperatures. 

Now Siberian scientists have discovered how they produce ethanol in winter in order not to freeze or to require hibernation.

In cold winter months, the concentration of ethanol in the blood of reindeers increases 1.3 times. 

The same occurs in wild Yakut horses, a breed that remain outdoors in temperatures below -60C.

Yakut reindeer and horses. Pictures: The Siberian Times

The process is not common to all deer species and is unique to reindeer, said Boris Kershengolts, chief researcher of the Institute for Biological Problems of Cryolithozone in Novosibirsk. 

‘Endogenous ethanol, acetaldehyde and enzymes that metabolise them are one of the systems that ensure adaptation to cold of various sorts of living organisms that inhabit extreme climate environment,’ he said. 

‘An increase in the level of acetaldehyde, which is an inhibitor of processes that involve oxygen, slows down metabolism, decreases heat transfer, and drops the body temperature by 7 to 8 degrees [centigrade] in reindeer and Yakut horses.

'At the same time, the level of endogenous ethanol in blood increases and acts as a highly effective source of energy in processes both involving and not involving oxygen.

'As a result, it allows adjustment of bio-energy processes to cold climate conditions.' 

Scientists find how the animals produce ethanol in winter as an anti-freeze giving them the survival spirit. Pictures: The Siberian Times

The research was highlighted in a recent article in Comparative and Ontogenic Biochemistry journal. 

‘During evolution, under extreme climatic conditions northern animals develop mechanisms of thermal homeostasis that enable them to perform their vital functions in an optimal regime,’ stated the article. 

‘The ability of the reindeer to well tolerate winter cold is due to perfect heat-insulating properties of their hair coat which provides a relatively narrow daily range of temperature changes in body temperature.

‘In winter, mobility of animals decreases, and there is a statistically significant decline in metabolic rates and oxygen consumption.’ 

Yakut horses and reindeer. Pictures: Galina Davydova, The Siberian Times