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My own Mammalogy exam 2 study guide

Chiroptera

Understand what makes Chiroptera unique among mammals and explore the vast global diversity of bats

  • Powered flight. Chiroptera means “hand wing”.

  • Sophisticated echolocation

  • Predominantly nocturnal

  • Some hibernate

  • Exhibit a wide range of life strategies

  • Provide large economic benefits to humans

Describe the basic life histories and strategies of bats We will dive deeper with eastern U.S. species

Microchiroptera

Megachiroptera

“Echolocating or micro bats”

“Old world fruit bats or flying foxes”

Every continent except Antarctica

Tropical and subtropical regions of Asia, Africa, Australia, and throughout the islands of the Indian Ocean and Oceania

Generally small size

Generally large size

Most use echolocation and have a developed tragus

Do not echolocate and do not have developed tragus

Predominantly insectivorous

Predominantly fruit and nectar eaters

Majority of bats

Bats have a number of different feeding strategies. Most types are insectivores, but they can also be:

  • Frugivores (fruit eating)

  • Carnivores (meat eating)

  • Sanguinivores (blood eating)

  • Nectarivores (Nectar eating)

  • Piscivores (fish eating)

Describe the morphology of bats and how that relates to their unique life strategies

Aspect ratio is wing length/width.

  • High aspect ratio(long narrow wings)= fast flight, lower maneuverability, generally open areas, and aerial hawking

  • Low aspect ratio (short, wide wings)= slow flight, higher maneuverability, generally cluttered habitat, and gleaning.

Wing loading: body mass/wing area

Describe how bats perceive their environment and locate resources

While many bats possess echolocation that allows them to “see” via hearing, those bats also have decent smell and vision. Most of these kinds of bats eat insects, meat, or fish.

Bats that do not possess echolocation have excellent vision and senses of smell, and they primarily consume fruit and nectar.

Understand modern threats facing bats and explore conservation work being done to protect bats

The biggest issue bats are facing right now is white-nose syndrome, a fungal infection that wakes up bats during hibernation too frequently, which causes them to burn through their energy too fast, essentially starving them.

Other issues:

  • Wind turbine collision

  • Pesticides

  • Habitat conversion and fragmentation

  • Human persecution

  • Artificial light at night

Conservation efforts:

  • Education/nonprofits

  • Habitat protection -> ESA & state protections

  • Cave closures

  • Research that informs management and conservation

  • Wind energy technology advancements

  • Large scale monitoring efforts

  • Citizen Science and Bat houses

Orders Monotremata and Marsupiala

Describe the major morphological differences between Prototherians (monotremes),

Metatherians (marsupials), and Eutherians (placentals)

i. Anatomy (pectoral girdle)

Monotremes have an interclavicle and resemble early synapsid pectoral girdles. Therians (marsupials and placentals) lack an interclavicle and have pectoral girdles that are very different from early synapsids.

ii. Reproduction

Monotreme females have a cloaca, 2 uteri, and large eggs. Males have 2-4 headed penises and internal testes (no scrotum)

  • Lay eggs,

  • have altricial young (helpless, dependent young),

  • echidnas lay eggs directly into their pouches,

  • platypuses keep egg in a nest or burrow

  • Mammae secrete directly onto skin, no nipples

Marsupial females have 3 vaginas (2 lateral vaginas and 1 medial vagina) and 2 uteri. Males have forked penises (to match the 2 lateral vaginas) and scrotums anterior to their penises.

  • altricial young

  • young climb from vaginal opening to nipple or pouch

  • Pouch=marsupium

Placentals:Placental females have 1 vagina and 1 uterus. Males have scrotums anterior to their penises

  • produce young along a gradient from altricial to precocial

  • long gestation periods relative to lactation period

Lactation is generally more energetically costly than gestation

Understand where extant marsupial originated and how they came to occupy only North America, South America, and Australia

Extant marsupials originated in South America and spread to North America via the Great Biotic exchange (Opposums) and to Australia by way of Antarctica.

Describe traits of orders of monotremes and marsupials

Ornithorhynchidae (platypus)

  • Monotypic (group that includes a single taxon): duck-billed platypus(Ornithorhynchus anatinus)

    • males have venomous spur (subaceous gland!): defend breeding territory, maybe predator defense

    • semiaquatic, semifossorial (bank burrows)

    • Insectivore

    • Electroreception in bill

Tachyglossidae (echidnas)

  • Two monotypic genera

    • short-beaked echidna (Tachyglossus aculeatus)

    • long-beaked echidna (Zaglossus bruijni)

      • insectivore, myrmecophagous

      • electroreception in bill

      • quills

Didelphimorphia (North and South America) Didelphidae (opossum)

  • polyprotodont (>4 upper incisors)

  • omnivore

  • opposable pollex (thumb or first digit on the forefoot), climbing

  • incrassated tails store fat in the base of their tail for periods of torpor

Paucituberculata (South America) Caenolestidae (shrew/rat opossum)

  • diprotodont (two prominent lower incisors)

  • insectivorous or omnivorous

Microbiotheria (South America) Microbiotheriidae

  • Single species- Monito del monte (little monkey of the mountains) (Dromiciops gliroides)

  • polyprotodont (>4 incisors)

  • frugivore

  • hibernates and engages in torpor

  • incrassated tails store fat in the base of their tail for hibernation/torpor

Dasyuromorphia (Australia)

  • Dasyuridae (17 genera and 76 species), Myrmecobiidae (1 species),Thylacinidae (Tasmainian ‘tiger’ [extinct])

  • carnivores & insectivores

  • many have incrassated tails

Peramelemorphia (Australia)

  • Peramelidae (Bandicoot), Thylacomyidae (bilbies [aka rabbit-eared bandicoots])

  • polyprotodont

  • omnivorous

  • syndactylous (second and third hind digits joined in a common skin sheath)

    • used for grooming

Notoryctemorphia (Australia) Notoryctidae (marsupial moles)

  • fossorial

  • insectivore

  • fusiform (torpedo like body)

Diprotodontia (Australia; 11 families)

  • Phascolarctidae (koalas), Vombatidae (wombats), Phalangeroidea (pygmy possums), Phalangeridae (bushtail possums), Pseudocheiridae (ringtail possums), Tarsipedidae (honey possum), Acrobatidae (feather-tailed gliders), Petauridae (more gliders), Potoroidae (potoroos and bettongs), Hypsiprymnodontidae (musky rat-kangaroo), Macropodidae (13 genera; wallabies, kangaroos)

  • highly diverse traits/adaptations

  • occupy many niches

Outline main points discussed in Gordon et al. 2021

  • Large herbivores have large impacts on the vegetation communities upon which they rely

  • Extirpation of large carnivores and conversion of forest/shrubland to ranchlands (grasses) and row crops across much of the Earth’s surface, which causes prey species populations to grow.

  • To reduce kangaroo abundance in Australia, the government enacted a cull. 70% of the population was in favor of the cull, the other 30% were very opposed. Outreach and education provided by journalists, film makers led to greater acceptance of culling policies (scientists and policy makers better understood concerns of citizens not in favor of lethal management, and citizens better understood the need for management)

  • Government needed to know how many kangaroos the environment could sustain without experiencing the negative impacts of herbivory.

  • Active management of kangaroo populations and conversations among scientists, members of the public, and government led to interest in managing for biodiversity, not only plant community and kangaroo health.

Afrotheria

Describe why taxonomists have created the Super Order Afrotheria.

Think about:

a) Historical biogeography and tectonics

Africa was isolated from ~105-~40mya

b) Phylogenetics

There are 2 main groups in Afrotheria: clade Afroinsectiphilia and clade Paenungulata. These are determined by genetics

c) Common characteristics

high vertebral counts, the relatively late eruption of the permanent dentition, and undescended testes remaining internal near the kidneys

Describe characteristics shared by each of the two clades within Afrotheria

Afroinsectiphilia:

  • Mostly insectivorous

  • some dental synapomorphies

Paenungulata:

  • Herbivores

  • hindgut fermenters

  • lateral molar progression (mesial drift [horizontal rather than vertical replacement]) (Proboscidea, Sirenia)

  • two mammae

  • Short nails (no big ‘claws’, no hooves)

Describe common characteristics shared among members of each order

Order Macroscelidea (sengis/elephant shrews)

  • proboscis (hence “elephant”)

  • large hind limbs

  • large ears

  • mostly insectivorous (dilambdodont), sometimes omnivorous

  • morphologically convergent with rodents

  • ecologically convergent with shrews (mostly)

  • socially monogamous

  • maintain intricate trail network

Order Afrosoricida

  • Insectivores

  • Convergent evolution

Order Tubulindentata

  • widely distributed south of Sahara Desert

  • insectivorous, largely myrmecophagous

  • long, sticky lounge like ant eater

  • peg like teeth (ant eaters lack teeth)

  • strong diggers, large burrow system, dig up ant/termite mounds

  • claws are unique nail/hoof like

  • cryptic

Order Proboscidea

  • large proboscis (‘trunk’)

  • large ears (radiators)

  • sparsely furred

  • fatty cushion on feet to support large body

Order Hyracoidea

  • Three hind toes, two with hoof-like nails

  • Glandular pads adapted to climbing on rocks and branches

  • Tree and rock species

  • Herbivores

  • Colonial

  • Upper incisors form tusks

  • Two, large cecum

Order Sirenia

  • 100% marine/aquatic

  • only herbivorous marine mammal

  • restricted to shallow waters where plants grow

Xenarthra, Scandentia and Dermoptera

Understand characteristics shared by members of Superorder Xenarthra

Only found in the western hemisphere

  • Xenarthra = “strange joints”, 2 supplemental processes on each vertebra.

  • low metabolic rate

  • low body temperature(34 degrees C compared to 36-38 degrees in most mammals)

  • no incisors or canines

  • if cheek teeth, peg-like

Compare and contrast characteristics of the two orders within Xenarthra

Pilosa

  • Herbivorous (sloths)

  • Myrmecophagous (anteaters)

  • large, recurved claws.

  • Sloths have multi chambered stomach with symbiotic microbes for breaking down plant material

  • Anteaters lack teeth

Cingulata

  • Myrmecophagous (armadillos)

  • homodont

Be able to discuss the motivation for, and key findings of, Pauli et al. 2014

The motivation for Pauli et al. is the fact that three-toed sloths descend trees to defecate despite high mortality in doing so. It was hypothesized that there must be a benefit to the sloths that outweighs the negative of predation. Previously, it was believed that the moths that lived in the sloth’s fur had a commensal, or phoretic, relationship with the sloth (the moths benefit, and the sloths are not affected at all, negatively or positively). Analysis of the algae in the fur of three-toed sloths vs two-toed sloths, which do not descend to defecate, revealed that three-toed sloth algae had more lipids and nutrients. These benefits were brought in by the moths. Therefore, the relationship between moths, sloths, and algae is three-way commensalism.

Primates

Describe the eight characteristics shared by all primates

1. Refined hands and digits with nails replacing claws

2. Binocular stereoscopic vision

3. Postorbital bar or plate

4. For their body size, especially long lived, slow reproduction, and extended developmental time

5. Spectrum of social systems (relatively asocial to highly social)

6. Bunodont molars, large canines, incisors (mostly omnivorous)

7. Reduced rostrum and sense of smell

8. Large absolute and relative brain size (high cognitive ability)

Name and describe differences between two suborders of primates

Haplorhini:

  • post orbital plate

  • relatively short rostrum

  • upper incisors continuous

Strepsirhini:

  • post orbital bar

  • relatively long rostrum

  • gap in upper incisors

Discuss in detail the factors that threaten primate populations and species across the

globe

The biggest factor is habitat loss from deforestation. The reasons for deforestation are lumbar/paper goods, conversion to agriculture, mining, high GDP countries investing in extractive resources, and global population growth. Other factors threatening primate populations are exploitation (pet trade, food, medical research) and climate change.

Rodentia and Lagomorpha

Describe general characteristics of Rodentia and what morphological features differentiate its suborders (skull and mandible morphology)

General characteristics of rodentia

  • Name Rodentia is derived from the Latin rodere (to gnaw) and dentis (tooth)

  • Single pair of large upper and lower incisors

  • Large incisors are ever-growing, used for clipping and gnawing

  • Anterior side of incisors covered with enamel and wears more slowly than the posterior side, which lacks enamel, creating characteristic chisel-like teeth

  • Diastema

Suborder skull morphology

  • Protragomorphous- no real muscle attachment at infraorbital foramen

  • Hystricomorphous - Huge infraorbital foramen (nickel sized)

  • Sciurmorphous- large infraorbital foramen

  • Myomorphous- small infraorbital foramen

Mandible morphology

  • Sciurognathous (simple/common angular process)

  • Hystricognathous (strongly deflected angular process) large jaw surface area for muscle attachment; stronger bite.

What features distinguish lagomorphs from rodents?

Fenestrated maxilla, Cecal/hindgut fermenters, second set of peg like incisors

What are the two families that comprise the Lagomorpha?

Ochotonidae (pikas)

  • Pareitals lack fenestra

  • No supraorbital process

  • Second incisor peg-like

leporidae (rabbits and hares)

  • Fenestrated fenestra

  • Supraorbital processes

  • Tiny second incisor

In what ways do hares and rabbits differ?

Hares

Rabbits

Offspring precocial, called “leverets”

Offspring altricial, called “kits”

postorbital process does not extend to parietal

postorbital process extends to parietal

Triangular interparietal bone absent

Triangular interparietal bone

Carnivora

Describe defining characteristics of Order Carnivora

  • Well developed canines

  • Carnassial pair teeth (P4, m1)(reduced in omnivores)

  • Well developed facial musculature

  • Large, c-shaped mandibular fossa

  • Anal scent glands (communication)

Describe key differences between suborders of Order Carnivora

Caniformes

Feliformes

longer rostrum, no transbullar septae

short rostrum, transbullar septae

No caniformes have retractable claws

Most (but not all) feliformes have retractable claws

Describe why carnivores need more space to survive than other mammals of similar size

Trophic pyramid: since carnivores eat meat and are higher up in the trophic pyramid, they need more space, since energy is reduced as it travels up the levels or the pyramid. Energy is reduced 10 times per energy level (each level gets 1/10 of the energy from the level below it), so higher levels need 10 times as much space per level to get as much energy.

This is a big issue with habitat loss and fragmentation.

Describe and define mesocarnivore release and trophic cascades

Trophic cascade: Indirect interactions between carnivores and plants mediated by direct interactions between carnivores and herbivores. There are 2 types: numerically mediated, wherein predators reduce the amount of prey, and behaviorally mediated, where predators change the behaviors of prey.

Mesocarnivore release: When a larger carnivore is removed from an area, smaller carnivores become more numerous, which leads to increased predation of small prey species and may cause declines in their population.

Describe challenges to the conservation of large carnivores

Habitat loss: since carnivores need more space than other animals of relatively similar body sizes and masses, they are more vulnerable to habitat loss and fragmentation.

Conflict with many human interests: livestock production, competition with humans for prey species like deer, they prey on pets, and are considered scary.

Felidae

With regards to taxonomy, focus on the two subfamilies

The two subfamilies, Pantherinae and Felinae, split around 10.8 million years ago. Both are monophyletic groups. Taxonomy is still not totally resolved

Describe differences between the two subfamilies

The biggest difference between the two families is the ability to roar or purr. Pantherinae (the big cats) have specially structured larynxes that allow them to roar but not purr, whereas Felinae (the small cats) have bony hyoids that let them purr but not roar.

Describe all the traits of Felidae and understand their function

  • All felids make these sounds: meowing, spitting, hissing, snarling, and growling.

  • Highly sensitive whiskers above eyes, on cheeks and muzzle, but not below the chin (navigate in dark and capture and hold prey)

  • Skull is foreshortened with a rounded profile and large orbits (kind of ball shaped)

  • Carnassials (premolar teeth specialized for shearing flesh from bone) and highly innervated canines to feel notches between vertebrae

  • Well developed sagittal crest where jaw muscles attach for powerful bite

  • Digitigrade (walk on toes). Paws on cats have glands between the toes. These interdigital glands secrete scent that cats use to mark territory

  • Most have retractable claws

  • Intervertebral discs contain extra elastic, spongy cushioning compared to those found in humans. Allows -flexible spine that can rotates opposite directions at the same time

  • Scapula and shoulder blades are free-floating, which allows them to fit through small spaces

  • Cat eyes have a tapetum lucidum, a layer of tissue in the eye lying immediately behind the retina. It reflects visible light back through the retina, increasing light available to the photoreceptors, which helps them see better in the dark

  • Tongue covered with 5 types of horny papillae or spines, which rasp meat from prey and aid in grooming.

  • Lack many taste buds, and cannot taste sweet.

  • Felids have a special sense receptor, vomeronasal organ (also Jacobson’s organ) in the roof of the mouth, allowing them to "taste" the air for food and pheromones. The use of this organ is associated with what is known as the Flehmen response

  • Cats have much shorter digestive tracts than other mammals and even other carnivores, since raw meat is more rapidly digested. Cats are obligate carnivores and cannot digest plant material.

  • Most cats are solitary, with the exception of lions

Orders Perissodactyla & Cetartiodactyla, Infraorder Cetacea

Describe what characteristics differentiate ungulates from other mammals

  • Walk on tips of their toes, which end in keratinized hoofs. (keratin is specialized skin cells)

  • Reduced number of toes (<5)

  • Heel bone (calcaneum) articulates with the astragalus rather than fibula like in other mammals (only in hind limbs)

Describe what differentiates Orders Perissodactyla and Cetartiodactyla

Perissodactyla have an odd number of toes (1,3), while cetartiodactyla have an even number of toes (2,4).

Perissodactyla also have hindgut fermentation and upper incisors, while most Cetartiodactyla have ruminant digestion (except suids) and no upper incisors (except suids)

Understand differences between three Families of Perissodactyls

Family Equidae

  • 7-9 species

  • Originated and diversified in

  • Great Basis of North America

  • Modern distribution across Africa and Eurasia

  • Most species are threatened or endangered

  • Cannon bone

  • Evolved from browser to grazer feeding strategies

Family Tapiridae

  • 2 genera, 4 species

  • Distributed across the tropics of South America and SE Asia

  • Inhabit dense forest, mixed feeders

  • Proboscis like rostrum

  • 4 toes on front foot, 3 toes on back

  • all threatened or endangered

Family Rhinocerotidae

  • 4 genera, 5 species

  • Name means “nose horn”

  • Characteristic horn(s) on rostrum, which have no bony core or keratinized sheath, simply a mass of keratinized fibers

  • All species threatened or endangered

  • Occupy tropical rainforests, floodplains, grasslands, and scrublands

Understand differences between Suborders of Cetartiodactyla

Suborder Ruminantia

  • All have horns or antlers

  • Globally distributed

  • Most economically important group

Suborder Suina

  • Two families

  • Pigs/hogs (Suidae) & peccaries (Tayassuidae)

  • Most primitive group of ungulates

  • Globally distributed except Antartica

  • Habitat generalists

  • Omnivorous

  • Monogastric digestion

  • Upper incisors, bunodont molars

  • Tusks

  • Large litter size

Suborder Tylopoda

  • Three-chambered stomach, “simple ruminants”

  • Distributed across South American and Eurasian deserts/arid grasslands

  • Soft hooves with nails (unlike other ungulates), adaptation for walking in sand, soft surfaces

Family Hippopotamidae (suborder Whippomorpha)

  • “River horse”, aquatic

  • Two genera, two species (common hippopotamus, pygmy hippotamus)

  • Diverged from cetaceans around 55 mya

  • Common hippo ~ 3,000 lb, second largest land mammal after elephants

  • Used to be grouped with pigs because bunodont molars

  • herbivorous, feed on land

  • hydrodefecator

  • large tusk-like canines

  • Used to be much more speciose

Describe Cetacean evolution, morphology, physiology

Cetaceans transitioned from land to sea during eocene (50 mya). Their ancestor was toothed, semi-aquatic, and foraged in shallow water, and also possessed an astragalus. As they transitioned to water animals, their nostrils moved backward and they lost their hind limbs.

Morphology:

  • Fusiform body type

  • Dense bones allow for diving

  • Blubber

  • “Telescoped” skull: posterior bones of the cranium are compressed and overlap one another to help protect the head from high pressure during dives

Physiology:

  • Dense bones aid diving

  • Rigid airways prevent collapse during dives

  • High oxygen efficiency:

    • Hematocrit (2x density of red blood cells)

    • Myoglobin (oxygen binding capacity in muscle cells)

    • Extra capillaries

    • Lung collapse

Be able to discuss key findings of Esmaeili et al. 2021

Similar to Jarman-Bell principle; bigger herbivores forage for plants in older phenological stages (which aren’t as high quality--provide less protein and are more fibrous) and smaller herbivores forage for earlier phenological stages (more protein).

My own Mammalogy exam 2 study guide

Chiroptera

Understand what makes Chiroptera unique among mammals and explore the vast global diversity of bats

  • Powered flight. Chiroptera means “hand wing”.

  • Sophisticated echolocation

  • Predominantly nocturnal

  • Some hibernate

  • Exhibit a wide range of life strategies

  • Provide large economic benefits to humans

Describe the basic life histories and strategies of bats We will dive deeper with eastern U.S. species

Microchiroptera

Megachiroptera

“Echolocating or micro bats”

“Old world fruit bats or flying foxes”

Every continent except Antarctica

Tropical and subtropical regions of Asia, Africa, Australia, and throughout the islands of the Indian Ocean and Oceania

Generally small size

Generally large size

Most use echolocation and have a developed tragus

Do not echolocate and do not have developed tragus

Predominantly insectivorous

Predominantly fruit and nectar eaters

Majority of bats

Bats have a number of different feeding strategies. Most types are insectivores, but they can also be:

  • Frugivores (fruit eating)

  • Carnivores (meat eating)

  • Sanguinivores (blood eating)

  • Nectarivores (Nectar eating)

  • Piscivores (fish eating)

Describe the morphology of bats and how that relates to their unique life strategies

Aspect ratio is wing length/width.

  • High aspect ratio(long narrow wings)= fast flight, lower maneuverability, generally open areas, and aerial hawking

  • Low aspect ratio (short, wide wings)= slow flight, higher maneuverability, generally cluttered habitat, and gleaning.

Wing loading: body mass/wing area

Describe how bats perceive their environment and locate resources

While many bats possess echolocation that allows them to “see” via hearing, those bats also have decent smell and vision. Most of these kinds of bats eat insects, meat, or fish.

Bats that do not possess echolocation have excellent vision and senses of smell, and they primarily consume fruit and nectar.

Understand modern threats facing bats and explore conservation work being done to protect bats

The biggest issue bats are facing right now is white-nose syndrome, a fungal infection that wakes up bats during hibernation too frequently, which causes them to burn through their energy too fast, essentially starving them.

Other issues:

  • Wind turbine collision

  • Pesticides

  • Habitat conversion and fragmentation

  • Human persecution

  • Artificial light at night

Conservation efforts:

  • Education/nonprofits

  • Habitat protection -> ESA & state protections

  • Cave closures

  • Research that informs management and conservation

  • Wind energy technology advancements

  • Large scale monitoring efforts

  • Citizen Science and Bat houses

Orders Monotremata and Marsupiala

Describe the major morphological differences between Prototherians (monotremes),

Metatherians (marsupials), and Eutherians (placentals)

i. Anatomy (pectoral girdle)

Monotremes have an interclavicle and resemble early synapsid pectoral girdles. Therians (marsupials and placentals) lack an interclavicle and have pectoral girdles that are very different from early synapsids.

ii. Reproduction

Monotreme females have a cloaca, 2 uteri, and large eggs. Males have 2-4 headed penises and internal testes (no scrotum)

  • Lay eggs,

  • have altricial young (helpless, dependent young),

  • echidnas lay eggs directly into their pouches,

  • platypuses keep egg in a nest or burrow

  • Mammae secrete directly onto skin, no nipples

Marsupial females have 3 vaginas (2 lateral vaginas and 1 medial vagina) and 2 uteri. Males have forked penises (to match the 2 lateral vaginas) and scrotums anterior to their penises.

  • altricial young

  • young climb from vaginal opening to nipple or pouch

  • Pouch=marsupium

Placentals:Placental females have 1 vagina and 1 uterus. Males have scrotums anterior to their penises

  • produce young along a gradient from altricial to precocial

  • long gestation periods relative to lactation period

Lactation is generally more energetically costly than gestation

Understand where extant marsupial originated and how they came to occupy only North America, South America, and Australia

Extant marsupials originated in South America and spread to North America via the Great Biotic exchange (Opposums) and to Australia by way of Antarctica.

Describe traits of orders of monotremes and marsupials

Ornithorhynchidae (platypus)

  • Monotypic (group that includes a single taxon): duck-billed platypus(Ornithorhynchus anatinus)

    • males have venomous spur (subaceous gland!): defend breeding territory, maybe predator defense

    • semiaquatic, semifossorial (bank burrows)

    • Insectivore

    • Electroreception in bill

Tachyglossidae (echidnas)

  • Two monotypic genera

    • short-beaked echidna (Tachyglossus aculeatus)

    • long-beaked echidna (Zaglossus bruijni)

      • insectivore, myrmecophagous

      • electroreception in bill

      • quills

Didelphimorphia (North and South America) Didelphidae (opossum)

  • polyprotodont (>4 upper incisors)

  • omnivore

  • opposable pollex (thumb or first digit on the forefoot), climbing

  • incrassated tails store fat in the base of their tail for periods of torpor

Paucituberculata (South America) Caenolestidae (shrew/rat opossum)

  • diprotodont (two prominent lower incisors)

  • insectivorous or omnivorous

Microbiotheria (South America) Microbiotheriidae

  • Single species- Monito del monte (little monkey of the mountains) (Dromiciops gliroides)

  • polyprotodont (>4 incisors)

  • frugivore

  • hibernates and engages in torpor

  • incrassated tails store fat in the base of their tail for hibernation/torpor

Dasyuromorphia (Australia)

  • Dasyuridae (17 genera and 76 species), Myrmecobiidae (1 species),Thylacinidae (Tasmainian ‘tiger’ [extinct])

  • carnivores & insectivores

  • many have incrassated tails

Peramelemorphia (Australia)

  • Peramelidae (Bandicoot), Thylacomyidae (bilbies [aka rabbit-eared bandicoots])

  • polyprotodont

  • omnivorous

  • syndactylous (second and third hind digits joined in a common skin sheath)

    • used for grooming

Notoryctemorphia (Australia) Notoryctidae (marsupial moles)

  • fossorial

  • insectivore

  • fusiform (torpedo like body)

Diprotodontia (Australia; 11 families)

  • Phascolarctidae (koalas), Vombatidae (wombats), Phalangeroidea (pygmy possums), Phalangeridae (bushtail possums), Pseudocheiridae (ringtail possums), Tarsipedidae (honey possum), Acrobatidae (feather-tailed gliders), Petauridae (more gliders), Potoroidae (potoroos and bettongs), Hypsiprymnodontidae (musky rat-kangaroo), Macropodidae (13 genera; wallabies, kangaroos)

  • highly diverse traits/adaptations

  • occupy many niches

Outline main points discussed in Gordon et al. 2021

  • Large herbivores have large impacts on the vegetation communities upon which they rely

  • Extirpation of large carnivores and conversion of forest/shrubland to ranchlands (grasses) and row crops across much of the Earth’s surface, which causes prey species populations to grow.

  • To reduce kangaroo abundance in Australia, the government enacted a cull. 70% of the population was in favor of the cull, the other 30% were very opposed. Outreach and education provided by journalists, film makers led to greater acceptance of culling policies (scientists and policy makers better understood concerns of citizens not in favor of lethal management, and citizens better understood the need for management)

  • Government needed to know how many kangaroos the environment could sustain without experiencing the negative impacts of herbivory.

  • Active management of kangaroo populations and conversations among scientists, members of the public, and government led to interest in managing for biodiversity, not only plant community and kangaroo health.

Afrotheria

Describe why taxonomists have created the Super Order Afrotheria.

Think about:

a) Historical biogeography and tectonics

Africa was isolated from ~105-~40mya

b) Phylogenetics

There are 2 main groups in Afrotheria: clade Afroinsectiphilia and clade Paenungulata. These are determined by genetics

c) Common characteristics

high vertebral counts, the relatively late eruption of the permanent dentition, and undescended testes remaining internal near the kidneys

Describe characteristics shared by each of the two clades within Afrotheria

Afroinsectiphilia:

  • Mostly insectivorous

  • some dental synapomorphies

Paenungulata:

  • Herbivores

  • hindgut fermenters

  • lateral molar progression (mesial drift [horizontal rather than vertical replacement]) (Proboscidea, Sirenia)

  • two mammae

  • Short nails (no big ‘claws’, no hooves)

Describe common characteristics shared among members of each order

Order Macroscelidea (sengis/elephant shrews)

  • proboscis (hence “elephant”)

  • large hind limbs

  • large ears

  • mostly insectivorous (dilambdodont), sometimes omnivorous

  • morphologically convergent with rodents

  • ecologically convergent with shrews (mostly)

  • socially monogamous

  • maintain intricate trail network

Order Afrosoricida

  • Insectivores

  • Convergent evolution

Order Tubulindentata

  • widely distributed south of Sahara Desert

  • insectivorous, largely myrmecophagous

  • long, sticky lounge like ant eater

  • peg like teeth (ant eaters lack teeth)

  • strong diggers, large burrow system, dig up ant/termite mounds

  • claws are unique nail/hoof like

  • cryptic

Order Proboscidea

  • large proboscis (‘trunk’)

  • large ears (radiators)

  • sparsely furred

  • fatty cushion on feet to support large body

Order Hyracoidea

  • Three hind toes, two with hoof-like nails

  • Glandular pads adapted to climbing on rocks and branches

  • Tree and rock species

  • Herbivores

  • Colonial

  • Upper incisors form tusks

  • Two, large cecum

Order Sirenia

  • 100% marine/aquatic

  • only herbivorous marine mammal

  • restricted to shallow waters where plants grow

Xenarthra, Scandentia and Dermoptera

Understand characteristics shared by members of Superorder Xenarthra

Only found in the western hemisphere

  • Xenarthra = “strange joints”, 2 supplemental processes on each vertebra.

  • low metabolic rate

  • low body temperature(34 degrees C compared to 36-38 degrees in most mammals)

  • no incisors or canines

  • if cheek teeth, peg-like

Compare and contrast characteristics of the two orders within Xenarthra

Pilosa

  • Herbivorous (sloths)

  • Myrmecophagous (anteaters)

  • large, recurved claws.

  • Sloths have multi chambered stomach with symbiotic microbes for breaking down plant material

  • Anteaters lack teeth

Cingulata

  • Myrmecophagous (armadillos)

  • homodont

Be able to discuss the motivation for, and key findings of, Pauli et al. 2014

The motivation for Pauli et al. is the fact that three-toed sloths descend trees to defecate despite high mortality in doing so. It was hypothesized that there must be a benefit to the sloths that outweighs the negative of predation. Previously, it was believed that the moths that lived in the sloth’s fur had a commensal, or phoretic, relationship with the sloth (the moths benefit, and the sloths are not affected at all, negatively or positively). Analysis of the algae in the fur of three-toed sloths vs two-toed sloths, which do not descend to defecate, revealed that three-toed sloth algae had more lipids and nutrients. These benefits were brought in by the moths. Therefore, the relationship between moths, sloths, and algae is three-way commensalism.

Primates

Describe the eight characteristics shared by all primates

1. Refined hands and digits with nails replacing claws

2. Binocular stereoscopic vision

3. Postorbital bar or plate

4. For their body size, especially long lived, slow reproduction, and extended developmental time

5. Spectrum of social systems (relatively asocial to highly social)

6. Bunodont molars, large canines, incisors (mostly omnivorous)

7. Reduced rostrum and sense of smell

8. Large absolute and relative brain size (high cognitive ability)

Name and describe differences between two suborders of primates

Haplorhini:

  • post orbital plate

  • relatively short rostrum

  • upper incisors continuous

Strepsirhini:

  • post orbital bar

  • relatively long rostrum

  • gap in upper incisors

Discuss in detail the factors that threaten primate populations and species across the

globe

The biggest factor is habitat loss from deforestation. The reasons for deforestation are lumbar/paper goods, conversion to agriculture, mining, high GDP countries investing in extractive resources, and global population growth. Other factors threatening primate populations are exploitation (pet trade, food, medical research) and climate change.

Rodentia and Lagomorpha

Describe general characteristics of Rodentia and what morphological features differentiate its suborders (skull and mandible morphology)

General characteristics of rodentia

  • Name Rodentia is derived from the Latin rodere (to gnaw) and dentis (tooth)

  • Single pair of large upper and lower incisors

  • Large incisors are ever-growing, used for clipping and gnawing

  • Anterior side of incisors covered with enamel and wears more slowly than the posterior side, which lacks enamel, creating characteristic chisel-like teeth

  • Diastema

Suborder skull morphology

  • Protragomorphous- no real muscle attachment at infraorbital foramen

  • Hystricomorphous - Huge infraorbital foramen (nickel sized)

  • Sciurmorphous- large infraorbital foramen

  • Myomorphous- small infraorbital foramen

Mandible morphology

  • Sciurognathous (simple/common angular process)

  • Hystricognathous (strongly deflected angular process) large jaw surface area for muscle attachment; stronger bite.

What features distinguish lagomorphs from rodents?

Fenestrated maxilla, Cecal/hindgut fermenters, second set of peg like incisors

What are the two families that comprise the Lagomorpha?

Ochotonidae (pikas)

  • Pareitals lack fenestra

  • No supraorbital process

  • Second incisor peg-like

leporidae (rabbits and hares)

  • Fenestrated fenestra

  • Supraorbital processes

  • Tiny second incisor

In what ways do hares and rabbits differ?

Hares

Rabbits

Offspring precocial, called “leverets”

Offspring altricial, called “kits”

postorbital process does not extend to parietal

postorbital process extends to parietal

Triangular interparietal bone absent

Triangular interparietal bone

Carnivora

Describe defining characteristics of Order Carnivora

  • Well developed canines

  • Carnassial pair teeth (P4, m1)(reduced in omnivores)

  • Well developed facial musculature

  • Large, c-shaped mandibular fossa

  • Anal scent glands (communication)

Describe key differences between suborders of Order Carnivora

Caniformes

Feliformes

longer rostrum, no transbullar septae

short rostrum, transbullar septae

No caniformes have retractable claws

Most (but not all) feliformes have retractable claws

Describe why carnivores need more space to survive than other mammals of similar size

Trophic pyramid: since carnivores eat meat and are higher up in the trophic pyramid, they need more space, since energy is reduced as it travels up the levels or the pyramid. Energy is reduced 10 times per energy level (each level gets 1/10 of the energy from the level below it), so higher levels need 10 times as much space per level to get as much energy.

This is a big issue with habitat loss and fragmentation.

Describe and define mesocarnivore release and trophic cascades

Trophic cascade: Indirect interactions between carnivores and plants mediated by direct interactions between carnivores and herbivores. There are 2 types: numerically mediated, wherein predators reduce the amount of prey, and behaviorally mediated, where predators change the behaviors of prey.

Mesocarnivore release: When a larger carnivore is removed from an area, smaller carnivores become more numerous, which leads to increased predation of small prey species and may cause declines in their population.

Describe challenges to the conservation of large carnivores

Habitat loss: since carnivores need more space than other animals of relatively similar body sizes and masses, they are more vulnerable to habitat loss and fragmentation.

Conflict with many human interests: livestock production, competition with humans for prey species like deer, they prey on pets, and are considered scary.

Felidae

With regards to taxonomy, focus on the two subfamilies

The two subfamilies, Pantherinae and Felinae, split around 10.8 million years ago. Both are monophyletic groups. Taxonomy is still not totally resolved

Describe differences between the two subfamilies

The biggest difference between the two families is the ability to roar or purr. Pantherinae (the big cats) have specially structured larynxes that allow them to roar but not purr, whereas Felinae (the small cats) have bony hyoids that let them purr but not roar.

Describe all the traits of Felidae and understand their function

  • All felids make these sounds: meowing, spitting, hissing, snarling, and growling.

  • Highly sensitive whiskers above eyes, on cheeks and muzzle, but not below the chin (navigate in dark and capture and hold prey)

  • Skull is foreshortened with a rounded profile and large orbits (kind of ball shaped)

  • Carnassials (premolar teeth specialized for shearing flesh from bone) and highly innervated canines to feel notches between vertebrae

  • Well developed sagittal crest where jaw muscles attach for powerful bite

  • Digitigrade (walk on toes). Paws on cats have glands between the toes. These interdigital glands secrete scent that cats use to mark territory

  • Most have retractable claws

  • Intervertebral discs contain extra elastic, spongy cushioning compared to those found in humans. Allows -flexible spine that can rotates opposite directions at the same time

  • Scapula and shoulder blades are free-floating, which allows them to fit through small spaces

  • Cat eyes have a tapetum lucidum, a layer of tissue in the eye lying immediately behind the retina. It reflects visible light back through the retina, increasing light available to the photoreceptors, which helps them see better in the dark

  • Tongue covered with 5 types of horny papillae or spines, which rasp meat from prey and aid in grooming.

  • Lack many taste buds, and cannot taste sweet.

  • Felids have a special sense receptor, vomeronasal organ (also Jacobson’s organ) in the roof of the mouth, allowing them to "taste" the air for food and pheromones. The use of this organ is associated with what is known as the Flehmen response

  • Cats have much shorter digestive tracts than other mammals and even other carnivores, since raw meat is more rapidly digested. Cats are obligate carnivores and cannot digest plant material.

  • Most cats are solitary, with the exception of lions

Orders Perissodactyla & Cetartiodactyla, Infraorder Cetacea

Describe what characteristics differentiate ungulates from other mammals

  • Walk on tips of their toes, which end in keratinized hoofs. (keratin is specialized skin cells)

  • Reduced number of toes (<5)

  • Heel bone (calcaneum) articulates with the astragalus rather than fibula like in other mammals (only in hind limbs)

Describe what differentiates Orders Perissodactyla and Cetartiodactyla

Perissodactyla have an odd number of toes (1,3), while cetartiodactyla have an even number of toes (2,4).

Perissodactyla also have hindgut fermentation and upper incisors, while most Cetartiodactyla have ruminant digestion (except suids) and no upper incisors (except suids)

Understand differences between three Families of Perissodactyls

Family Equidae

  • 7-9 species

  • Originated and diversified in

  • Great Basis of North America

  • Modern distribution across Africa and Eurasia

  • Most species are threatened or endangered

  • Cannon bone

  • Evolved from browser to grazer feeding strategies

Family Tapiridae

  • 2 genera, 4 species

  • Distributed across the tropics of South America and SE Asia

  • Inhabit dense forest, mixed feeders

  • Proboscis like rostrum

  • 4 toes on front foot, 3 toes on back

  • all threatened or endangered

Family Rhinocerotidae

  • 4 genera, 5 species

  • Name means “nose horn”

  • Characteristic horn(s) on rostrum, which have no bony core or keratinized sheath, simply a mass of keratinized fibers

  • All species threatened or endangered

  • Occupy tropical rainforests, floodplains, grasslands, and scrublands

Understand differences between Suborders of Cetartiodactyla

Suborder Ruminantia

  • All have horns or antlers

  • Globally distributed

  • Most economically important group

Suborder Suina

  • Two families

  • Pigs/hogs (Suidae) & peccaries (Tayassuidae)

  • Most primitive group of ungulates

  • Globally distributed except Antartica

  • Habitat generalists

  • Omnivorous

  • Monogastric digestion

  • Upper incisors, bunodont molars

  • Tusks

  • Large litter size

Suborder Tylopoda

  • Three-chambered stomach, “simple ruminants”

  • Distributed across South American and Eurasian deserts/arid grasslands

  • Soft hooves with nails (unlike other ungulates), adaptation for walking in sand, soft surfaces

Family Hippopotamidae (suborder Whippomorpha)

  • “River horse”, aquatic

  • Two genera, two species (common hippopotamus, pygmy hippotamus)

  • Diverged from cetaceans around 55 mya

  • Common hippo ~ 3,000 lb, second largest land mammal after elephants

  • Used to be grouped with pigs because bunodont molars

  • herbivorous, feed on land

  • hydrodefecator

  • large tusk-like canines

  • Used to be much more speciose

Describe Cetacean evolution, morphology, physiology

Cetaceans transitioned from land to sea during eocene (50 mya). Their ancestor was toothed, semi-aquatic, and foraged in shallow water, and also possessed an astragalus. As they transitioned to water animals, their nostrils moved backward and they lost their hind limbs.

Morphology:

  • Fusiform body type

  • Dense bones allow for diving

  • Blubber

  • “Telescoped” skull: posterior bones of the cranium are compressed and overlap one another to help protect the head from high pressure during dives

Physiology:

  • Dense bones aid diving

  • Rigid airways prevent collapse during dives

  • High oxygen efficiency:

    • Hematocrit (2x density of red blood cells)

    • Myoglobin (oxygen binding capacity in muscle cells)

    • Extra capillaries

    • Lung collapse

Be able to discuss key findings of Esmaeili et al. 2021

Similar to Jarman-Bell principle; bigger herbivores forage for plants in older phenological stages (which aren’t as high quality--provide less protein and are more fibrous) and smaller herbivores forage for earlier phenological stages (more protein).

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