We have all heard in the news about the stresses global warming and the associated climate changes are causing organisms in the north. The polar bear has become some what of a poster child for the impacts of global warming in the north. However,researchers are now reporting on the impacts even small changes in the tropics can have on animals there.
The tropics teem with insects which are ectotherms. These animals vary their metabolic rate with their environment. As the environment warms, their metabolism rises, and they need to eat more. The most current estimate I know of places the number of insect species in the tropics at about 3.7 million. This is a huge reduction from the previously held estimate of 30 million. The real number would be somewhere in between the two I suspect.
In any case, there are millions of insects that are being affected by warming. Why does this matter? Insects are key to life in the tropics. They play all kinds of important roles. They are a rich source of food for other animals, they are pollinators of the flowering plants that dominate the tropics, and some keep the population numbers of other species in check.
As warming causes their body temperatures to rise, their metabolic rates rise and they have to eat more, or reduce their activity to conserve the food they have.
To see a Science Digest article about this topic click here.