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What we’ve covered so far: Didelphimorphia Didelphidae – opossums (1 B.C. ) Soricomorpha Soricidae – (9 B.C. species) Talpidae – moles (3 B.C. species) What’s next: Rodentia Sciuridae – (16) – mice, , lemmings, voles (16) Aplodontidae – (1) – beaver (1) – jumping mice (2) Erethizontidae – N. American porcupines (1) Geomyidae – pocket (1) – kangaroo rats, pocket mice (1) diversity Order Rodentia

• Dentition highly specialized for gnawing • Incisors: o single pair of upper, single pair of lower o grow continuously (rootless) o enamel on anterior surface, not posterior surface Order Rodentia

• Dentition highly specialized for gnawing • Incisors • Diastema • No canines Sciuridae Family Sciuridae

• Postorbital process well-developed

• Rostrum short, arched

• Infraorbital canal reduced relative to many other

• 1/1 0/0 1-2/1 3/3, anterior premolar sometimes small and peg-like Glaucomys sabrinus—northern flying

• Can glide 5-25 meters • Strictly nocturnal • Share , reduce activity in winter because of cold Glaucomys sabrinus—northern

• Conspicuous notch anterior to postorbital process • 5 upper cheekteeth Marmota spp. – 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. caligata • M. vancouverensis • M. flaviventris Marmota monax - woodchuck

• Posterior border of nasals forms a “V” • Maxillary row < 21 mm Marmota vancouverensis – Vancouver Island

• Posterior border of nasals forms a “V” • Maxillary row > 21 mm Marmota caligata –

• 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) carolinensis –

• 5 upper cheekteeth; P1 small and peg-like • Infraorbital foramen a canal on the side of the rostrum • 2 transbullar septae spp. – ground squirrels, rock squirrels

• 5 cheekteeth per side – no peg-like cheekteeth • Flattened 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

• 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 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 , 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 spp. - chipmunks Tamias spp. - chipmunks

• 5 upper cheekteeth; P1 small and peg-like • Infraorbital canal pierces zygomatic plate Tamias townsendii – Townsend’s

• Skull length > 37 mm • Maxillary toothrow length > 6 mm • Pale, indistinct stripes on back and head Tamias minimus –

• 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- 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

• Ventral pelage white or gray • Range: most of BC including Red squirrel midden