High arctic avian athlete gives lessons about animal welfare


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. It is light all day in summer and in winter
it is about minus 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. 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 analyzing 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. 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. 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. 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. 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 all 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. 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.

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