LONDON - Animals that hibernate in winter are abandoning hibernation in yet another signal that something momentous is happening to the rhythms of the natural world.
Hibernation has evolved for the same reason most animal behaviour has evolved - as a strategy to maximise survival.
Some creatures thatneed a lot of energy to get around have learned to shut themselves down in winter, when the food to provide that energy is simply not available, or too much energy would be expended in searching for it.
Biologists have realised that many species have an instinctive and finely tuned way of weighing up the balance between how much effort needs to be expended to acquire a certain food item, and how much energy is available, in return, in the item acquired.
The general law is: If the second is less than the first, don't do it.
This has been called "optimal foraging".
Two conclusions can be drawn from European brown bears in the Cantabrian mountains in northern Spain stopping hibernation. First, something quite enormous is happening in the world around them and that something is almost certainly global warming.
Secondly, they are abandoning a survival strategy that has been successful, for the unknown.
What if they give up hibernation because of rising winter temperatures, but then when they are active in winter, are unable to find enough food?
Climate change is perceived as a terrible problem for human society but we should not lose sight of the fact that, to the natural world and its inhabitants, the warming also presents a mortal predicament.
