3/22/2007 - Rodent teachings - More gleanings from the mammology class.

With over 2,000 living species placed in about 30 families, rodents are by far the largest order of mammals.  This makes up 40 percent of all mammal species.  I find 28 species of rodents listed for Iowa, 13 of which most people would loosely label as a mouse.

Although many are small, a few can range to 100 pounds or so.  During the age of mammals backing in the pliostcene some rodents were Rhino sized and actually had horns!

Obvious features of rodents are the gnawing separate front teeth. The teeth grow throughout the rodents life ever wearing away and being replaced by new growth.  Some have molars that are also continuously growing, so its probably safe to assume that tooth decay is never a problem.

Reproducing more rodents is of course another specialty.  An acre of prairie grass might have an even dozen white footed mice in it at a high density, but each of those mice are busy making 40-50 more mice a year.

While rabbits are only somewhat closely related, it is estimated that a single pair might create 350,000 more rabbits through 5 years of breeding.  Certainly mice would outpace that.

In the diverse group there are naked mole rats who live an almost hive insect-type life with a queen. 

The porcupines live in both North America and Africa and are quite distinct from each other.  They are not the only prickly rodents.  There are spiny rats which also would be dangerous to pet as their back has sharp spines on it.

Many are food sources for indigenous populations.  And it goes without saying that many are pests of the agriculture industry. 

It would be interesting to know if the rat has killed more people by spreading disease (such as bubonic plague) or help save more peoples lives as a laboratory test animal.

Certainly some rodents like beavers and muskrats have made a lot of people a lot of money with harvesting of their fur.  On the other hand beavers for example can flood a lot of valuable real estate in short order, ruining agricultural crops.  Lets not forget that the beaver essentially fueled westward expansion during the fur trade era.

What’s the value of a rodent to forest trees.  Certainly many are quite dependent upon rodents hiding and scattering their seeds and nuts, and then later forgetting to eat them all.

Some give us sports teams names and mascots (The Golden Gophers).

In rodents diverse nature, you may have to look at the bumps on their feet, or the grooves in their teeth to be able to tell them apart.

Their diverse diet tends to be herbivorous, but many are omnivorous, a few are quite carnivorous, and still more are cannibalistic!

They also give us some interesting terms such as ricochetal which describes hopping without using the front feet, saltation, jumping with the use of front feet, crepuscular (to move about during twilight),  and fossorial (to live underground).

Lastly, a few make surprisingly good pets.  Perhaps not as affectionate at being played with as dogs and cats, but still tolerant of being handled a lot.