Page 120 - Engineering in Nature

Engineering in Nature

they achieve the requisite temperature for flight. 38
At first scientists assumed that this success stemmed from the
moths' metabolisms and carried out research in that area. To that end,
they measured the winter moth's metabolic rates at rest, during shiv-
ering, and in flight. Yet the figures they obtained were roughly the
same as those for other species of moth, of the same weight. It was
thus realized that the moths' warming had nothing to do with the
speed of their metabolisms. As a result, it emerged that winter moths
have a heating system that is unique to this species.

Stage 2: Finding a Protective Shelter
The research into winter moths began with the temperature and
humidity of its environment, because the freezing process starts with
ice crystals forming in the winter moth's body. In drier environments,
the moths' freezing temperature drops to rather low levels. Therefore,
how do the moths find a shelter to protect themselves from ice and
sudden temperature drops?
Even when the outside air temperature is around -30°C (-22°F), the
temperature beneath the leaf layer covering the ground seldom falls
below -2 degrees C (28°F). When the temperature does plunge below
-2°C (28°F), the winter moths conceal themselves under the leaves,
which act like a kind of blanket, until the air temperature rises
enough to support them again. Whereupon other systems in the
moths' bodies go into action to keep them alive.

Stage 3: The Natural Anti-Freeze Mechanism in Winter
Moths
To stop the water in our car radiators from turning to ice, we use
anti-freeze. But few people know that some living things actually
have anti-freeze-like chemicals in their own bodies to protect them

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