1. Rodentia Gnawing Mammals - Andrew Marmo

2. Skull Characteristics  A pair of upper and lower incisors Single open root Continuously growing  Enamel on outside and exposed dentine on inside  Diastema between incisors and premolars

3. Order Rodentia  Largest order of mammals with over 2000 species  40% of mammals are rodents  Found on all continents except for Antarctica  Size and breeding cycle may be the reason for their success.

4. Common House Mouse (Mus musculus)  Reach sexual maturity at about 4 weeks of age.  Breed year round  6 mice can turn into a family of 60 in 3 months

5. Cricetidae  Includes true hamsters, voles, and New World rats and mice.  Almost 600 species  Second largest family of mammals. -Largest in North America

6. Deer Mouse (Peromyscus maniculatus)  Inhabit nearly all types of land in PA  Eat seeds, berries, mushrooms, beetles, slugs, and spiders.  Name refers to their coats resemblance to a deer.

7. Southern Red-Backed Vole (Clethrionomys gapperi)  Found in much of upland PA  Favors cool damp forests with hemlocks, mossy rocks, and stumps  Climbs into low trees

8. Muskrat (Ondatra zibethicus)  Mainly found in wetlands  Can stay submerged for up to 17 minutes  Feed mostly on aquatic vegetation  Builds dome shaped huts

9. Castoridae Beaver Castor canadensis  Largest rodent in NA  Can way up to 70 lbs.  One of the few species that pair for life  Estimated 30,000 in PA. (PA GC)

10. Erethizontidae Porcupines Erethizon dorsatum  Second largest rodent in PA  Top speed is 2 miles per hour  Den in caves, rock crevices, hollow logs, and trees

11. Sciuridae Squirrels  Includes tree squirrels, ground squirrels, chipmunks, marmots, prairie dogs, flying squirrels, and woodchucks.

12. Eastern Gray Squirrel Sciurus carolinensis  Can run as fast as 14 mph and jump 6 feet between trees  Black coloration (melanism) is fairly common  Dens in tree cavities and leaf nests

13. Fox Squirrel Sciuris niger  PA is northern extent of its range  Larger than Gray Squirrel  Rare in deep forests, prefers park- like woods

14. Red Squirrel Tamiasciurus hudsonicuas  Prefers mature forests of white pine and hemlock  Eat everything from pine seeds to the young of birds  Store pinecones, nuts, and fruits in caches called middens

15. Southern Flying Squirrel Glaucomys volans  More common than northern flying squirrel in PA  Can sail up to 40 feet  Most predaceous of the tree squirrels

16. Eastern Chipmunk Tamias striatus  Active in the day (diurnal)  Prefer open deciduous woods  Become torpid in the winter, respiration falls from 60 to less than 20 breaths per minute

18. Works Cited  UCMP. Introduction to the Rodentia...  NaturePhoto. Rodents. 2011.. . Pennsylvania Wildlife. 08/22/10..