Skulls, Skins, Natural History - Carnivora, Monotremata, Didelphimorphia

• elongated rostrum

• edentulous

Monotremata, Tachyglossidae, Tachyglossus aculeatus

• insectivorous (primarily ants and termites)

• uses dens, burrows, and natural shelters

• lays eggs

Tachyglossus aculeatus

• very distinct and prominent sagittal crest

• polyprotodont

Didelphimorphia, Didelphidae, Dedelphis virginiana

Didelphis virginiana

• scavengers but also eats berries, insects, and eggs

• nocturnal

• no hibernation

• rarely carry rabies due to low body temperatures

• dens in hollow logs/trees, abandoned burrows, rock crevices, brush/wood piles

Didelphis virginiana

• prominent sagittal crest,

• large, c-shaped mandibular fossa

• large braincase relative to body size

• carnassial pair common

Carnivora

• flat skull, reduced rostrum

• 101-129 mm length

Carnivora, Mustelidae, Lontra (Lutra) canadensis

• 34-53 mm

• 3 upper premolars

• auditory bullae nearly twice as long as wide

• posterior edge of palantines rounded and extend beyond M1

Carnivora, Mustelidae, Neogale (Mustela) frenata

• <36 mm

• 3 upper premolars

• auditory bullae nearly twice as long as wide

• posterior edge of palantines rounded and extend beyond M1

Carnivora, Mustelidae, Mustela erminea

• >54 mm

• 3 upper premolars

• auditory bullae nearly twice as long as wide

• posterior edge of palantines rounded and extend beyond M1

Carnivora, Mustelidae, Neogale (Mustela) vison

• 4 upper premolars

• auditory bullae elongated but not twice as long

Carnivora, Mustelidae, Martes americana

• 4 upper premolars

• auditory bulla not elongated

• skull at least 99 mm in length

Carnivora, Mustelidae, Pekania pennanit

• flat skull

• reduced rostrum

• >125 mm length

Carnivora, Mustelidae, Enhydra lutris

• M1 squarish

• palate does not extend appreciably beyond M1

Carnivora, Mephitidae

• bunodont molars

• rounded cranium

• poorly-developed carnassials

• palate terminated posteriorly to molars

Carnivora, Procyonidae, Procyon lotor

• broad, powerful rostrum

• 2 upper molars

• 3 lower molars

• diameter of upper canines >12 mm

Carnivora, Canidae, Canis lupus

• 2 upper molars

• 3 lower molars

• long, narrow rostrum

• diamater of upper canines <12 mm

Carnivora, Canidae, Canis latrans

• temporal ridges form a “V”

• sagittal crest not as well-developed

Carnivora, Canidae, Vulpes vulpes

• temporal ridges form a “U”

• sagittal crest not as well-developed

Carnivora, Canidae, Urocyon cinereoargenteus

• digitigrade

• claws retract, used for attacking prey

• shearing molars and well-developed carnassials

• short rostrum with 1-2 lower molars

Felidae

• 2 upper premolars

• much smaller than Puma

Carnivora, Felidae, Lynx rufus

• 3 upper premolars - have carnassial form, third has anterior cusp for crushing bone

Carnivora, Felidae, Puma concolor

• large claws

• massive rostrum

• poorly developed carnassials

• crushing cheek teeth

Carnivora, Ursidae, Ursus americanus

• relatively large skull with large nasal opening

Carnivora, Phocidae, Phoca vitulina

Neogale (Mustela) frenata

• can kill 4x its mass

• start hunting when ~7 weeks old

• sexual size dimorphism (males 1.5x size of females)

• seasonal molts at higher latitudes

• most widespread mustelid in North America

Neogale (Mustela) frenata

• exhibits seasonal molts and cryptic coloration

• 4-5 year cycles with voles and lemmings at northern latitudes

• sometimes use rodent burrows as dens, circumpolar distribution

Mustela erminea

Neogale (Mustela; Neovison) vison

• semi-aquatic, preying on fish, crayfish and frogs

• historically an economically important furbearer (currently, most fur comes from individuals raised on fur farms, trapping still legal in 47 states)

• dens in abandoned beaver/muskrat lodges

Neogale (Mustela; Neovison) vison

• one of the largest geographic distributions of any mammal

• smallest extant carnivore (average mass ~55g)

• seasonal molts at higher latitudes

Mustela nivalis

Martes americana

• old-growth confierous and mixed forest specialist (deforestation has restricted range)

• variety of vocalizations (huffs, chuckles, and shouts)

• economically-important furbearer (trapping still primary cause of mortality in some populations)

• den on ground but are often found in trees

Martes americana

• large tracts of forested and semi-forested landscapes, with a preference for mature forests that have a high canopy and dense undergrowth

• variety of vocalizations (low growls, grunts, hisses, snarls, chortle)

• economically-important furbearer (trapping still primary cause of mortality in some populations

• den in hollow logs, cavities in trees, rock crevices, and brush piles

Pekania pennanit

Gulo gulo

• scavengers but also eat berries, insects, and eggs

• historically an economically important furbearer (still heavily protected)

• dens under trees and near ravines (many times in snow)

Gulo gulo

Lontra (Lutra) canadensis

• oily, thick coat (20,000 - 30,000/year trapped for fur)

• close their nostrils under water

• vibrassae (whiskers) help them sense prey underwater

• among most social mustelids (groups made up of females and offspring) (males and females together only for breeding)

Lontra (Lutra) canadensis

• oily, thick coat (heavily protected from fur trade)

• close their nostrils under water

• vibrassae (whiskers) help them sense prey underwater

• great at controlling sea urchin populations

Enhydra lutris

Mephitis mephitis

• aposematic coloration

• kits can spray musk at 8 days (thiols)

• typically warm (stamp feet) prior to spraying

• male offspring leave mother their first fall, females not until following spring (both reproductively mature at ~10 months)

• bred specifically as pets in some places

Mephitis mephitis

Spilogale putorius

• aposematic coloration

• climbs trees

• sprays from “handstand” position

Spilogale putorius

Procyon lotor

• omnivorous

• commensal with humans in many areas

• weigh 5 - 15lbs in wilderness (up to 60lbs in urban/suburban areas)

• dexterous hands

• males don’t participate in raising kits

• do not hibernate

Procyon lotor

Canis lupus

• complex social system based around family dynamic (breeding adult pair and their offspring)

• pup disperse after 10 - 54 months, triggered by onset of sexual maturity and/or competition with food within pack

• habitat generalist, but prefer remote areas

Canis lupus

• occupied southeastern US before mid-1900s

• thought to have preferred swamps and bottomland river forests of the SE

• pre-extirpation diet consisted of rodents, rabbits, and nutria

• 23 - 25 individuals in the wild currently

Canis rufus

Canis latrans

• produce litters of 4 - 7 pups

• live in either pairs or family “packs”

• broad diet (everything from fruit to vertebrates)

• habitat generalist, large geographic range

• currently recolonizing urban/suburban landscapes

Canis latrans

Vulpes vulpes

• most widespread canid species in the world

• one home range typically occupied by one adult male, one or two adults females, and their offspring (pup)

Vulpes vulpes

Urocyon cinereoargenteus

• typically occur in deciduous wooded areas

• only canid in North America that climbs trees (flexible forelimbs and semi-retractible claws)

• solitary except when breeding/raising pups (winter)

Urocyon cineroeoargenteus

Vulpes lagopus

• most restricted range of foxes

• various pelage based on season

• feed on small mammals, birds, and seal pups

• pelage varies

Vulpes lagopus

Lynx rufus

• solitary and territorial

• prey on many small vertebrates (specialize on cottontails)

• used to be extensively hunted for fur

• currently recolonizing urban/suburban landscapes

Lynx rufus

• widespread carnivore, extirpated from eastern US

• historically, widest distribution of all terrestrial American mammals

• will take many small and large prey (specialize on deer)

  • 860-1300 kg/year (humans - 88kg meat/year)

• in some areas, will migrate between summer and winter home ranges

Puma concolor

• omnivorous

• excellent sense of smell (Jacobson’s organ)

• extirpated from non-forested habitats

• winter lethargy (time varies regionally)

• cubs nurse throughout winter, emerge weighing 2 -5kg

Ursus americanus

• “eared” seal

• fastest of all seals/sea lions

Carnivora, Otariidae, Zalophus californianus

• “earless” seal

• inflatable sac on their nose

Carnivora, Phocidae, Cystophora cristata

• “earless” seal

• can spend up to 2 days at sea foraging for food

• can dive underwater for up to 30 minutes

Carnivora, Phocidae, Halichoerus grypus

• occur in both temperate and polar regions

• highly specialized for an aquatic existence (cumbersome movements on land)

• may occur in fresh water

• primarily consume fish and mollusk

• ear hole, no flap

• scoots on belly while on land

Phocidae

• occur in both temperate and polar regions

• highly specialized for an aquatic existence (cumbersome movements on land)

• don’t occur in fresh water

• primarily consume fish and mollusks

• ear with flap

• “walking” on land

Otariidae

• “earless” seal

• most abundant seal species in northern hemisphere

• migrate up to nearly 5,000km round trip

Carnivora, Phocidae, Pagophilus groenlandicus

• “earless” seal

• up to 85% of their day can be spent foraging

• seen in the Chesapeake Bay

Carnivora, Phocidae, Phoca vitulina