Upload
others
View
5
Download
0
Embed Size (px)
Citation preview
Lagamorpha and Rodentia
http://www.animalpicturesarchive.com/ArchOLD-2/1105698202.jpg
Order Lagamorpha
• Two Families– Ochotonidae– Leporidae
• Characteristics– Diastema– 4 upper incisors (this
is how you tell Lagamorphs from Rodents)
Order Lagomorpha, Family Ochotonidae—pikas
1) jugal projects posteriorly almost to meatus 2) no supraorbital process
Family Ochotonidae
• Activity: – Diurnal– Active year round.
• Diet:– Grasses, sedges, thistles,
and fireweed.– Will eat some food on the
spot and store the rest in a pile called a “haystack”.
• Highly territorial – Use vocalizations in
territorial displays.
Ochotona collaris (Collared pika)
• Range: – Alaska – Northwestern Canada– Southwestern Canada– Western U.S.
Ochotona princeps (American pika)
• Range:– Lower BC– Eastern Alberta– Parts of Western
Canada
Order Lagomorpha, Family Leporidae—rabbits and hares
1) jugal projects posteriorly, but not to meatus 2) supraorbital processes
snowshoe hare—Lepus americanus white-tailed jackrabbit—Lepus townsendii
1) no interparietal 2) postorbital processes broad and winglike
Lepus spp. (hares and jackrabbits)
• Activity: – Nocturnal-crepuscular.– Active year round
• Some have white winter pelage
• Generally do NOT use burrows.
• Males fight for females during long breeding season
• Northern species exhibit cyclic fluctuations in population density.
Photo: Flickr
Lepus americanus (Snowshoe hare)
• Range:– Throughout Canada– Alaska– Extreme Northern U.S.
and much of Western and Eastern U.S.
Lepus townsendii (White-tailed jackrabbit)
Photo: Smithsonian Museum of Natural History
Photo: Flickr
eastern cottontail—Sylvilagus floridanus mountain cottontail—Sylvilagus nuttalli
1) distinct interparietal on adults 2) postorbital processes thinner than Lepus
Sylvilagus spp. (cottontails)
• Activity: – Nocturnal-crepuscular.– Active year round
• Pelage does not turn white in winter.
• Some use burrows.• Coprophagous• Range:
– Southern Canada though South America
www.animalpicturesarchive.com
Sylvilagus nuttalli (Mountain cottontail)
Sylvilagus floridanus (Eastern cottontail)
Order Rodentia, Family Aplodontidae—mountain beaver Aplodontia rufa—mountain beaver
1) cranium is triangular and flattened dorso-ventrally 2) auditory bullae are flask-shaped 3) cheek teeth with prominent outer projections
Aplodontia rufa (Mountain beaver)
• Activity:– Active day or night
• Diet:– variety of plant
material• Range:
– Southwest BC to Northern California
• Stores food in burrow.– Territorial defense of
burrow Photo: Washington Dept of Fish and Wildlife
Order Rodentia, Family Dipodidae—jumping mice
1) incisors grooved 2) massive infraorbital foramen 3) 4th upper premolar small and peg-like
Dipodidae (jumping mice)• Activity:
– Primarily nocturnal• Profound hibernators
– Usually dormant early fall to mid-spring
– Double weight in fat prior to hibernation, no food storage
• Diet:– primarily seeds, but also
eats fungus, nuts, berries, and insects.
• Normally move slowly but jump when startled– Long tail and large feet aids
jumping• Range:
– most of BC, Canada, and Eastern U.S.
Photo: Animal Diversity Web
Zapus trinotatus—Pacific jumping mouse
1) crescent-shaped fold on upper premolar
Zapus hudsonius—meadow jumping mouse
1) no fold on upper premolar
Zapus hudsonius
Order Rodentia, Family Castoridae—beavers Castor canadensis—American beaver
1) jugal is conspicuously broad 2) long bony tube surrounding external auditory
meatus 3) incisors massive
Castoridae (beavers)
• Activity:– Diurnal and Nocturnal– Active year round.– Semiaquatic
• Paddle-like tail, webbed feet• Form family groups, slightly
colonial.• Monogamous• One of the largest rodents• Diet:
– bark, cambium, twigs, and leaves. Eats aquatic plants in summer.
• Range: – Nearly all of North America
Order Rodentia, Family Erethizontidae—American porcupines Erethizon dorsatum—North American porcupine
1) massive infraorbital foramen 2) incisors massive 3) auditory bullae larger than Castor canadensis
Erethizontidae (New World porcupines)
• Activity: – Largely nocturnal
• Covered with barbed quills. Feet modified for aboreal life
• Diet: – Fall/Winter: evergreen
needles, cambium, inner bark of trees.
– Spring/Summer: buds, twigs, leaves, flowers, berries, and nuts.
– Bacteria in digestive tract capable of breaking down cellulose.
• Range: – North America and Northern
Mexico
Order Rodentia, Family Geomyidae—pocket gophers Thomomys talpoides—northern pocket gopher
1) postorbital processes inconspicuous 2) upper and lower cheek teeth form “8”s 3) nasals do not project anteriorly to incisors
Geomyidae (Pocket gophers)• Activity:
– Almost entirely fossorial
• Live in burrow system• Diet:
– Underground roots, rhizomes, and bulbs.
– Water obtained from food– Food stored underground
for winter.
• Range: – Southern Canada to
PanamaPhoto: Flickr
Thomomys talpoidesGeomys bursarius
Order Rodentia, Family Heteromyidae—heteromyids Perognathus parvus—Great Basin pocket mouse
1) grooved upper incisors 2) inflated auditory bullae almost touch anteriorly 3) delicately built zygomatic arch
Heteromyidae (pocket mice, kangaroo rats, and mice)
• Activity:• Nocturnal• Live in and store food
in burrows.• Do not require
drinking water.• Range:
– Southern Canada though Western and Central U.S. into Mexico
www.biotropics.co.uk