Due to changing climates, research suggests how species unable to adapt may see a stunt in their growth.

Warmer global climates and fluctuating weather patterns are already having an effect on the growth of some species. The polar bear, for instance, are experiencing lower ice levels and consequently decreasing in size. Another shrinking animal is a bird called the graceful warbler. From 1950 to 1990, the bird reduced in size by 26 percent.

Some others undergoing the same change in size include: cotton, corn, strawberries, bay scallops, carp, frogs, etc. According to the report in Nature Climate Change, 38 out of 85 animal and plant species are said to be shrinking in size over recent decades.

As study co-author at the University of Alabama explains, plants and animals don't need to grow as big as things are becoming warmer. At least for cold-blooded animals, warmer weather means their metabolic systems work faster, resulting in more burnt calories.

The overall trend scientists are seeing now may be affecting just the size of animals over long periods, but species unable to adapt may eventually be threatened by extinction.

The research was published on Sunday in the Nature Climate Change journal.