How to

24 May 2016

How Animals Survive in Sub-Zero Temperatures

Animals astound, fascinate, terrify and inspire us, but they can also teach us how to create things. The study of animals has led to a number of ground-breaking inventions, some of which might surprise you. The nose of the Japanese bullet train is based on the beak of a kingfisher, gecko feet have been studied to help create powerful new adhesives and shark skin has led to massive developments in the way boat hulls are coated, as well as a new kind of ultra-hygienic wrapping for hospital surfaces.

It tends to be the case that we study animals for technological purposes because they’ve mastered something which still causes us a lot of problems. Surviving in low temperatures is most certainly one of those things, so what can we learn from the various ways animals deal with it?

Using Anti-Freeze

No, I’m not talking about wolverines breaking out a spray bottle to defrost an elk carcass, I’m talking about animals being able to create a kind of natural anti-freeze within their own bodies. Crazy, right? Not if you’re a wood frog. This North American species has gained a reputation for surviving in very difficult climates and habitats, including deep cold. This is partially because their bodies contain higher quantities of sugar, urea and a series of amino acid substitutions, all of which allow their bodies to function at temperatures as low as -28 Celsius.

Sharing Body Heat

Even in less cold temperatures, this behaviour can be observed. Some species of snake will form massive piles as the sun heats their blood to share the warmth. In sub-freezing climates, it becomes an essential tool for staying alive. Emperor penguins group together in massive huddles, numbering in the hundreds. Members will alternate between time spent in the warmer inner regions of the huddling, and the icy outer rim, walking the perimeter to keep the blood pumping.

Slowing Down

As much as moving around can is a vital technique in low temperatures, many animals deal with the drop by going torpid. Torpor is a state where the metabolic rate and body temperature lowers, allowing animals to function whilst saving the energy they would otherwise be using to maintain a high body temperature. Some animals will go torpid for short periods each day, like birds, small mammals and marsupials, whilst others will go into that state and remain there for weeks or even months, otherwise known as hibernation. This can be an almost impossibly low state of activity, the red-eared slider turtle effectively goes into a coma during its hibernation period, sometimes even underwater.

Hiding Beneath the Snow

You might not think that burrowing into deep snow is an appropriate way to keep warm, but if we hadn’t observed animals behaving this way, we might have never invented the igloo. The area in and beneath the snowpack is known as the subnivean, and it traps a layer of warmth between the ground and the snow. Many small animals can exist there for long stretches, eating the vegetation preserved beneath (and each other). Rodents are particularly dependant on the subnivean climate, but reptiles, insects and even small birds also use it. 

Callum Davies

Callum is a film school graduate who is now making a name for himself as a journalist and content writer. His vices include flat whites and 90s hip-hop.