Study: Rodents Swell and Shrink to Remarkable Sizes on Islands

posted: 06/23/15
by: Discovery.com Staff
Scurrying rodent

Scientists have long known that, when isolated on an island, certain populations of animals can evolve over time to either remarkably huge sizes or stunningly tiny sizes. Known as "the island rule", the phenomenon was previously thought to have excluded rodents.

Researchers from Duke University now think that rodents are in on the size madness. As part of a new study published in the open-access journal Duke Space, biologists Paul Durst and Louise Roth analyzed size data from 60 species of rodents around the world.

Based on their research, Durst and Roth concluded that half of the rodent populations found on islands weigh in at the top or bottom 2.5% of all rodents in their species.

Some rodents, such as Central America's Coues' rice rat, have grown to be more than twice the size of their mainland relatives.

The rodents on the smaller end of the spectrum tended to live in barren environments that lack the lush vegetation of their mainland counterparts, which impacts their development. "They don't have the resources they need to get big," explains Durst.

Click here to read the full study in Duke Space

Learn more about rodents:

show more details
Giant Beaver

About the blog:
DSCOVRD: The best of the web, covering space, technology, wildlife and more!
More on