Ecologists say climate change will shrink species.

The degradation of ecosystems around the world due to climate change is limiting food availability, so smaller animals that need less food are thriving. Selective pressures such as those caused by overfishing -- which favors the smaller ones that can reproduce while they are still small -- are also part of the equation.

But mainly, warmth itself limits species size. Smaller species radiate heat more easily to adapt to warm temperatures. Bergmann's rule says that species size decreases as warmth increases, towards the tropics. Larger animals have a lower surface-area-to-volume ratio, allowing them to retain more heat and fare better in a cold climate.

As a result, as Wendy Foden, the World Conservation Union biologist studying the effects of climate change on species, says: "As the world gets warmer, species will shrink."

British population biologist Andy Purvis adds that dying young will also alter species size. He expects them to shrink because they'll be coping with sudden changes in their environment and hence dying prematurely, leading to smaller offspring over time.

Via Livescience
Artwork courtesy Slinkachu