What we ve covered so far: Didelphimorphia Didelphidae opossums (1 B.C. species) Soricomorpha Soricidae shrews (9 B.C. species) Talpidae moles (3 B.C. species)
What s next: Rodentia Sciuridae squirrels (16) Muridae mice, rats, lemmings, voles (16) Aplodontidae mountain beaver (1) Castoridae beaver (1) Dipodidae jumping mice (2) Erethizontidae N. American porcupines (1) Geomyidae pocket gophers (1) Heteromyidae kangaroo rats, pocket mice (1)
Rodent diversity
Order Rodentia Dentition highly specialized for gnawing Incisors: o o o single pair of upper, single pair of lower grow continuously (rootless) enamel on anterior surface, not posterior surface
Order Rodentia Dentition highly specialized for gnawing Incisors Diastema No canines
Family Sciuridae
Family Sciuridae Postorbital process well-developed Rostrum short, arched Infraorbital canal reduced relative to many other rodents 1/1 0/0 1-2/1 3/3, anterior premolar sometimes small and peg-like
Glaucomys sabrinus northern flying squirrel Can glide 5-25 meters Strictly nocturnal Share nests, reduce activity in winter because of cold
Glaucomys sabrinus northern flying squirrel Conspicuous notch anterior to postorbital process 5 upper cheekteeth
Marmota spp. marmots and woodchuck
Marmota spp. marmots and woodchuck Rows of cheek teeth parallel, or nearly so Postorbital processes protrude at 90
Marmota spp. marmots and woodchuck M. monax M. vancouverensis M. caligata M. flaviventris
Marmota monax - woodchuck Posterior border of nasals forms a V Maxillary row < 21 mm
Marmota vancouverensis Vancouver Island marmot Posterior border of nasals forms a V Maxillary row > 21 mm
Marmota caligata hoary marmot Posterior border of nasals forms an arch Maxillary row > 21 mm
Marmota flaviventris yellow-bellied marmot Posterior border of nasals forms an arch Maxillary row < 21 mm
Sciurus carolinensis eastern gray squirrel Dorsal pelage variable (often gray, but can be light-colored or even black) Long bushy tail (>50% body length)
Sciurus carolinensis eastern gray squirrel 5 upper cheekteeth; P1 small and peg-like Infraorbital foramen a canal on the side of the rostrum 2 transbullar septae
Spermophilus spp. ground squirrels, rock squirrels 5 cheekteeth per side no peg-like cheekteeth Flattened zygomatic plate
Spermophilus spp. ground squirrels, rock squirrels Maxillary toothrow > 10 mm S. columbianus S. parryii Maxillary toothrow < 10 mm S. lateralis S. saturatus
Spermophilus columbianus Columbian ground squirrel Range: southern BC interior east of Rockies Concerns about poisoning by ranchers worried about competition with livestock Side of neck grayish
Spermophilus parryii Arctic ground squirrel Range: northwest BC Highly colonial, with hundreds of animals per colony and a few dominant males Eat carcasses of animals Side of neck reddish Ventral side of tail reddish with black tip
Spermophilus lateralis golden-mantled ground squirrel Range: Rocky Mountains Prominent black stripes bordering light stripes on back and mantle Unlike chipmunks, no stripes on face
Spermophilus saturatus Cascade mantled ground squirrel Range: southern Cascades (limited range could pose conservation risk) Black stripes on back; mantle inconspicuous Unlike chipmunks, no stripes on face
Tamias spp. - chipmunks
Tamias spp. - chipmunks 5 upper cheekteeth; P1 small and peg-like Infraorbital canal pierces zygomatic plate
Tamias townsendii Townsend s chipmunk Skull length > 37 mm Maxillary toothrow length > 6 mm Pale, indistinct stripes on back and head
Tamias minimus least chipmunk Skull length < 33 mm, toothrow < 6 mm Total length < 195 mm Distinct stripes on back and head Range: northern half of BC
Tamias amoenus yellow-pine chipmunk Skull length 33-37 mm, toothrow < 6 mm Total length > 195 mm Distinct stripes on back and head Range: southern half of BC
Tamias ruficaudus red-tailed chipmunk Skull length 33-37 mm, toothrow < 6 mm Total length > 195 mm Distinct stripes on back and head Range: extreme southeastern BC
Tamiasciurus spp. American red squirrels 4 upper cheekteeth Zygomatic arches parallel or nearly so 3 transbullar septae
Tamiasciurus douglasii Douglas squirrel Ventral pelage yellow or orange Range: southwestern BC
Tamiasciurus hudsonicus North American red squirrel Ventral pelage white or gray Range: most of BC including Vancouver Island
Red squirrel midden