Video transcript: High arctic avian athlete gives lessons about animal welfare

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February 2011

Dr Jonathon Codd, University of Manchester
So as a biologist you are always interested in how animals are adapted to their environment and Svalbard rock ptarmigans have extreme adaptations because they live in such an extreme place high up in the Arctic.

Video shows still images of ptarmigan and its natural habitat, then shows one waking across a rocky landscape

It is light all day in summer and in winter it is about -20 and it is complete dark and covered in snow. What they do is something very unique and something very special for a bird. They actually double their body mass from summer to winter and this is something we are interested in trying to understand how they cope by gaining this extra body mass. If you think about putting a backpack on or carrying a heavy load you notice that it is very hard work, if you are bringing some shopping or something, it's a lot of energy to do this. So if you have got a natural animal model that can gain body mass yet still function efficiently, this is what we are primarily interested in studying.

Video shows two different ptarmigans in the laboratory running on a custom-built treadmill

The way we are able to study this is that we actually train these birds to run on a treadmill so we have them running inside a clear Perspex box and by analysing the air in the box when the bird is running at different speeds and when the birds are thin in summer and fat in winter, we are then able to calculate the amount of energy that these birds use to run and live around these different conditions.

Video shows a ptarmigan in its natural habitat 'grounded running' on the ground

The two things we have found about these birds so far are that they are extremely efficient at moving around and, especially in summer, when they actually switch to running around they actually experience a drop in energy costs so ptarmigans extremely efficiently and this probably relates to the males having to run around, chase after females during the mating season.

The other interesting adaptation we have seen in these birds is that in winter when their body mass has doubled and they are very fat they stop running around. They prefer to walk or to ground run but they are also able to experience an energy saving in doing this as well so they also have adaptations for efficient moving in winter when they are very fat.

Dr Robert Nudds, The University of Manchester
Ptarmigan have the same gates that we see in humans so at slow speeds they walk and at high speeds they aerial run. The different between the two gates is that during aerial running you have your feet off the ground and as you travel through the air and your foot hits the ground again for the next stride the tendons in your legs operate like springs so you can imagine there is a spring just like a pogo stick in your leg.

Video shows a ptarmigan in the laboratory running on a custom-built treadmill, Dr Nudds then briefly demonstrates how a human produces a running motion in the same way

The spring is compressed as your body weight falls onto that leg and as you launch again for the next step that spring springs you forward and you continue running. The different between birds and humans is the birds have a bird gate between walking and running which is called grounded running and this gate shows characteristics of both walking and aerial running.

Video shows a ptarmigan in its natural habitat 'grounded running' on the ground

In the ptarmigan what we found was that we get the drop in energy expenditure with walking speed and then the line flattens out, the energy expenditure flattens out, and continues flatly al the way through grounded running and then when the bird switches to aerial running we get another drop in the energy expenditure. So we can see that the benefit for switching from grounded running to aerial running - you are saving energy.

Dr Jonathon Codd, University of Manchester

So what we have got with the Svalbard rock ptarmigan is that we have got a natural animal model that is able to survive and cope extremely well in an extreme environment with large fluctuations in body mass so what we are hoping is that the results that we have been able to get from this study are going to have strong implications for understanding things like how to improve animal welfare and the welfare of broiler chickens in particular