F&W Ecol Lec Exam 1

Phenetic Classification

• Based on overall similarity of observational traits

• Only considers structural and morphological characteristics

Cladistic Classification

• Based on shared derived characteristics that can be traced to a recent common ancestor

• Considers evolutionary relationships and ancestry

Taxonomic Ranks

(Domain), Kingdom, Phylum, Class, Order, Family, Genus, Species

Monophyly

traceable to/descend from a common ancestor

Paraphyly

doesn’t include all descendants from common ancestors

polyphyly

compares two unrelated groups

Characteristics unique to mammals (9)

• mammary glands

• hair/fur

• 3 inner ear bones

• single dentary bone

• dentary-squamosal jaw articulation

• complex teeth

• external ears (pinnae)

• non-nucleate red blood cells

• muscular diaphragm

Other mammal characteristics

• endothermy

• 4-chambered heart

• highly developed brain, nervous system

• centrally placed limbs

Origin of mammals

synapsid reptiles

Anapsid

• only eye and nasal fossa

• turtles

synapsid

• 1 fossa

• mammals

Diapsid

• 2 fossa

• snakes, lizards, tuataras, crocodilians, birds

3 types of mammalian reproduction

• monotreme

• marsupials (metatherians)

• placental (eutherians)

monotreme

egg-laying

marsupials (metatherians)

• live-bearing with pouch

• metatherians

placental mammals (eutherians)

• live-bearing with placenta

• eutherians

• ∼94% of living mammals

Skin Glands (4)

• mammary glands

• sweat glands

• sebaceous glands

• scent glands

mammary glands

nourish the young

sweat glands

evaporative cooling

sebaceous gland

oil to lubricate skin and hair

scent gland

mate attraction, territory marking, communication

Endothermy/Homeothermy

• Endothermy: internal heat source (metabolic heat)

• Homeothermy: constant body temperature

• Advantage: active over greater range of temperatures—nocturnal lifestyle

• Disadvantage: greater energy demands

Heterothermy

• endotherms that have the ability to fluctuate their body temperature to save energy (for daily torpor and/or to hibernate)

skull, jaws, and teeth

• large brain case

• single dentary bone in lower jaw

• inner ear bones evolved from articular and quadrate or reptilian jaw

  • stapes, incus, malleus

• differentiated teeth

dental formula

• I/I, C/C, P/P, M/M

  • upper/lower incisors, canines, premolars, and molars on ONE side of mouth

• Example—dog & bear: 3/3 1/1 4/4 2/3

mammalian skeleton features

• simplified and more completely ossified relative to reptile

• centrally placed limbs, articulating knees and elbows

• differentiated vertabrae

types of locomotion/stance (3)

• plantigrade—walk on flat feet

• digitigrade—walk on toes

• unguligrade—walk on hooves

brain characteristics (3)

• large, well-developed cerebrum

• neocortex folded in many species to increase surface area

• important role for memory, learning, rationalization, thought, etc

Senses (4)

• olfaction

• hearing

• vision

• touch

Olfaction

key role in foraging, mating, and social communication

hearing

highly developed in many species; some use hearing to echolocate

vision

variable; color vision poorly developed in most

touch

vibrissae (whiskers) act as tactile sensors

Subgroups of mammals

• monotremes

• marsupials

• placentals

Order: Monotremata

• 2 families

• 5 species

• Distribution: Australia, Tasmania, New Guinea

Monotreme characteristics

• egg-laying

• single opening (cloaca) at posterior end

• long, leathery, sensitive snout

• no functional teeth on adults

• epipubic bones present

Monotreme Examples

• Echidnas (Family Tachyglossiaae)

• Duck-billed Platypus (Family Ornithorhynchidae)

Order: Marsupials

• aka Metatheria

• 7 families (only need to know Didelphimorphia)

• 395 species

• Distribution: (1) Australia, New Guinea, & eastern Indonesian islands (2) South, central, and north america

Marsupial characteristics (6)

• Marsupium (pouch) in most species

• Epipubic bones present

• short gestation, prolonged lactation

• small, narrow braincase

• 5/4 incisors

Didelphimorphia (Family) (Order of Marsupial)

• American Opossums

• 126 species

• opposable hallux on hind feet

• prehensile tail

• primarily in South an Central America

• 1 species north of Mexico (Didelphis virginiana—Virginia opossum)

Virginia opossum (Didelphis virginiana)

• Family: Didelphidae

• sharp sagittal crest, tiny brain case

• Opposable hallux (Big toe)

• omnivorous scavenger

• Range: eastern US south through central americas, introduced to west coast

  • range expanding north

Placental orders in WI

• Cingulata (armadillos)

• Lagomorpha (lagomorphs—rabbits, hares, pikas)

• Rodentia (rodents)

• Eulipotyphla (shrews, moles, hedgehogs)

• Chiroptera (bats)

• Carnivora (carnivores)

• Artiodactyla (even-toed ungulates, whales, dolphins)

Most common mammal orders

1. Rodentia

2. Chiroptera (bats)

3. soricomorphs (shrews and moles

4. primates

Placental mammal superorders

1. Afrotheria

2. Xenarthra

3. Laurasciatheria

4. Euarchontoglires

Cingulata (armadillos) characteristics

• shell composed of bony plates covered with leathery skin

• simple, peg-like teeth—homodont

• short, thick limbs an large, heavy claws

• most specials fossorial (burrow)

• distribution: south an central America north to central US (1 species—Dasypus novemcinctus)

Dasypus novemcinctus (nine-banded armadillo)

• unmistakable body armor with 9 bands in center

• omnivorous

• forests and brushland habitats

• not established in WI but moving north slowly

Euliopotyphla (shrews, moles, hedgehogs)

• distribution worldwide except Antarctica and Australia

• 5 families

(Euliopotyphla) Family Soriciae (shrews)

• occurs worldwide except australia and antarctica

• small narrow snout, small eyes and ears

• NO zygomatic arches or auditory bullae on skull

• high metabolic rate—eat 2x body weight daily

• diet of mostly invertabrates

• some venomous species

• short-lived, multiple litters per year

Sorex cinereus—Masked shrew

• grayish brown fur

• long tail

• 3-4inch total length

• widespread in moist deciduous an coniferous forests in WI

Sorex hoyi—Pygmy shrew

• similar to S. cinereus—ONLY distinguishable by unicuspid teeth

• smallest N american mammal (3.1-3.6in)

• occurs in all but SW WI

• less abundant than s. cinereus

Sorex arcticus—Arctic shrew

• tricolor fur pattern

• 4-5in total

• boreal forest species

Sorex palustris—water shrew

• 5.4-6.5in

• large feet w fringe of stiff hairs adapted for swimming

• forages in and near water

• found in marshes, bogs, and streams in N half of WI

• species of special concern in WI

Blarina brevicauda—short-tailed shrew

• dark fur, large body, short tail

• 4.3-5.5in

• venomous saliva

• eats small verts and inverts

• common throughout WI

(Euliopotyphla) Family Talpidae (moles and desmans)

• most mole species—fossorial

• desmans—semi-aquatic

• tiny eyes, flattened head, short legs, large claws

• skull flattened, zygomatic arch and auditory bullae present

Scalopus aquaticus—eastern mole

• grey-brown fur, plump body, short tail, large forelegs an claws

• 5.9-7.9in

• digs tunnels in moist sandy or loamy soils

• diet mostly inverts

• solitary, annual breeder

• occurs in S and W WI

Condylura cristata—star-nosed mole

• tentacles at tip of snout act as sensory organ

• prefers wet soils near water

• solitary, annual breeder

• diet of terrestrial and aquatic inverts

• occurs in N and E WI

Order Chiroptera (bats)

• 1 family in WI

• 8 species in WI

• ∼22% of all living mammal species

• distributed worldwide except polar regions and highest mountains

bat characteristics

• flight

• nocturnal activity period

• hibernation, daily torpor, migration

• K-selected (long life span, low reproductive rate)

• various diets

Bat size ranges

• smallest: Kitti’s hog-nosed bat (bumblebee bat)—1.1-1.3in

• largest: flying foxes—wingspan up to 5.6ft

Skull identification bats vs shrews vs moles

• bats—nasal branches of premaxilla are not fused (appears as a gap)

• shrews—lacks zygomatic arch. has pigmented teeth

• moles—zygomatic arch and auditory bullae present

Echolocation

• used for foraging and navigation

• ear and face morphology facilitates sound detection

Bat dietary specilizations (5)

• bird-eating

• frog-eating

• fish-eating

• sanguivorous (feeds on blood)

• frugivorous/nectarivorous (most do not echolocate)

Bat benefits to ecosystem

• role in food chain

• pollination

• seed dispersal

• nutrient transfer (gunao—poop)

• keystone species in some tropical forests, deserts, an cave ecosystems

Bat economic benefits

• insect pest control

• many bat-reliant tropical fruits and other plants

• bat guano (poop) used as fertilizer

• biomedical research—bat immune sys

• Research on flight mechanics, echolocation, social behavior, etc

bats as disease vectors

• low incidence of rabies (∼0.1% of bats) but most frequent vector for rabies in humans

• serve as reservoirs for many human viruses (COVID, SARS, ebola, measles, mumps, etc)

White-nose syndrome (WNS)

• deadly fungal infection affecting cave-dwelling bats in E US

• causes bats to wake during hibernation, depleting energy reserves

Bats and wind turbines

• significant source of mortality for migratory tree-roosting bats

• most bats die from barotrauma

  • barotrauma: internal hemorrhaging caused by quick changes in air pressure

Bat conservation efforts

• surveillance and monitoring of bat pops

• protection of caves and other hibernacula

• greater use of bat houses

• 4 bat species protected in WI