Mammalian diversity (approximately 354 native mammal species)

low #families of mammals as compared to other continents

large radiation of marsupials due to geological history – most diverse (arid, semi-arid environments, nutrient poor)

more eutherians than most people think

defining characteristics – suite of characters that go together 1) hair (but some don’t) 2) warm blooded, endothermic 3) distinct jaw structure (useful for fossils) 4) feed young on milk

1) Class Mammalia, subclass Prototheria, order Monotremata – 2 species (approximately

1%) o family Ornithorhynchidae – platypus o family Tachyglossidae – echidnas

2) Class Mammalia, subclass Theria, infraclass Marsupialia o 4 orders, 17 families, approximately 156 known species in Australia (approximately 44%) o oldest marsupial fossils ~120mya, ~50—60my mark for Australian fossils, oldest in North

America and China

o order Peramelina family Peramelidae – bandicoots

family Thylacomyidae – bilbies

o order Dasyuromorphia – carnivorous marsupial, 56 species family Dasyuridae – dasyurids (quolls, antechinus, dunnarts, Tasmanian devil) family Thylacinidae – Tas tiger family Myrmecobiidae – numbat, only 1 species

- very specialist feeding niches - heavily impacted by forestry practices - vulnerable to predation by cats and foxes - feeds on social insects – termites - strictly diurnal – forages in the day (most marsupials are nocturnal)

o order Notoryctemorphia

family Notoryctidae – marsupial moles, 2 species - highly convergent with eutherian moles in Europe - swims underground – adapted for life underground: very reduced eyes - feeds on invertebrates

o order Diprotodontia – 86+ species suborder Vombatiformes, 4 species

- superfamilies Vombatomorphia and Phascolarctomorphia – common wombat, koalas - down east coast in forested systems + 2 arid zone species (southern and northern

hairy nosed wombat)

suborder Phalangeriformes – possums, 26 species - superfamilies Phalangeroidea and Petauroidea - eg. striped possum, mountain brush-tailed possum - diverse ecology and habitat use – eg. rainforest, wet forest, arid zone - diverse behaviour and mating strategies

down eastern coastline in forests

arid zone group

critical weight range mammals affected by introduced predators and habitat loss

suborder Macropodiformes – macropods; kangaroos, wallabies, potoroos, 56 species - families Macropodidae, Potoroidae and Hypsiprymnodontidae - eg. eastern grey kangaroo, western grey kangaroo, red kangaroo

3) Class Mammalia, subclass Theria, infraclass Eutheria – may actually be a bigger group than

marsupials, 196 species (approximately 55%)

o order Chiroptera – bats, approximately 64 species only flying mammal on earth suborder Megachiroptera—fruit bats suborder Microchiroptera – microbats

o order Rodentia – rats and mice, approximately 64 species (~18% of native Australian fauna) single pair of continuously growing incisors – top bottom jaw band of enamel on anterior side of incisors no canines or premolars morphologically, taxonomically and physiologically diverse evolutionary history – rodents appear in world fossil record 60 mya (late Paleocene),

recent group on all continents except Antarctica and Australia 30mya (Oligocene)

- good colonizers - evolved very rapidly - endothermic, but do not require much food

in Asia at least 30mya Asian and Australian continental plates collided 15—20my rodents invaded Australia from Asia (PNG, Indonesia) – first records 4.5my (old

endemics)

world rodent diversity Australian rodent diversity 3 suborders, 28 families, 430 genera, 2000+ species (in a single order! very diverse taxonomically)

1) Sciuromorpha - squirrels, beavers, gopher

pocket mice etc. - widespread group, not native

in Australia

2) Caviomorpha - cavy-like rodents – cavies,

capybaras (biggest), porcupines, guinea pigs etc.

- widespread group, not native in Australia

3) Myomorpha - mouse-like rodents

- most widespread group, only group native to Australia – radiated into a range of niches

suborder Myomorpha, family Muridae – 57 living species + 7 extinct in Australia - rats and mice – body plans not diverse - 5 families in world, 1 family in Australia (2 subfamilies) – not very diverse

taxonomically - strong links with PNG, lots of shared fauna with Indonesia

1) subfamily Hydromyinae, 49 species - in Australia ~4.5mya - 13 genera, 49 living, 7 extinct species - 4 teats (+1 sp. with 6 teats) - suffered most decline since European settlement - three tribes – radiated in different environments after arrival in

Australia, therefore various adaptations evolved to live in environment

1) Conilurini o typically arid o eg. greater stick nest

o carries huge sticks and pile them up to build nests – protection against predators

o particular habitat requirements easily destroyed by stock animals, high level of

disturbance from gazing by cattle (sheep etc.) habitat destroyed rapidly

o highly social: builds massive nests, lives in colonies

o vulnerable to predation without nest

o nests used over many generations – energetic cost of building a nest is reduced –

more efficient being a social group

o eg. genus Notomys (9 species, occus in PNG & Philippines as well) – Mitchell’s hopping mouse

o eg. pebble mound mouse

2) Hydromyini (amphibious) o eg. water rat, Hydromys

o eg. false water rat

3) Uromyini o northern forests (more forest dwelling) o eg. giant white tailed rat – good chewers o eg. fawn-footed Melomys – feeds on fruits and leaves, distribution

goes into PNG o eg. prehensile-tailed rat, Pogonomys

2) subfamily Murinae, 8 species - in Australia ~40000 years (newcomers) - invasion from Asia

- single genus: Rattus – 8 species, 8—12 teats

Class Mammalia, subclass Theria, infraclass Marsupialia, order Diprotodontia, suborder Macropodiformes, Superfamily Macropodoidea

1) Family Hypsiprymnodontidae, 1 species left

musky-rat kangaroo

thought to be like an ancestral macropod – many primitive characteristics

ancestor may be a primitive possum

o very arid zone distribution – highly adapted

o capable of very high vertical leap – probably for predator avoidance

o good at hopping – energy efficient in a nutrient poor environment

o convergent evolution between Australian hopping mice (F:Muridae) and

African jerboa (F: Dipodidae) – evolved in the same way in response to

similar environments: nutrient poor, arid, energy-poor diet etc.

several species

can carry stones up to half of body weight

mound built over entrance to burrow – probably to keep

entrance stable and be protected from predators

Australia’s largest native rat, up to 1.2kg

evolved in wetter environments – water dependent

bob as they swim

do not breed fast – ~3/4 babies at a time

limited distribution

on coastal areas with a lot of people activity

impacted by urban development

only discovered in 1974

6 teats

more radiated in PNG

feeds on leaves – highly arboreal when feeding

very white under belly

look like Melomys but have a blunter head and do not run as

well

tail curls upwards around branch when feeding

feeds mostly on fruits and seeds that fall on the ground from trees, occasionally invertebrates and vertebrates

characteristics: o upper canines o prehensile tail o first toe opposable – can grip around brances etc. o bounding gait – bounces along, able to get along quicker than possums when on the ground o two young (unlike other macropods) o diurnal activity

2) Family Potoroidae, 10 species

upper canines

prehensile tail

does not climb

uses tail to carry resting material about and brings back to nest to line nest with it

threatened

require dense cover to be kept safe from predators like foxes

eg. long-nosed potoroo (~1kg), Rufous bettong (biggest of Potoroidae, ~4kg)

3) Family Macropodidae Sub-family Sthenurinae, 1 species?

o short-faced kangaroo – big, boofy pushed in face o browsed around low trees and shrubs o dentition indicates it may have fed on wattles etc. – used arms to pull branches down o ~2/3 times larger than macropods o all extinct except banded hare-wallaby? – teeth and other skeletal characteristics differ from

other wallabies

Sub-family Macropodinae (true macropods), 61 species o Pademelons

eg. Red-legged Pademelon, Tasmanian Pademelon

o Rock-wallabies, 15 species

eg. brush-tailed rock wallaby, yellow-footed rock wallaby

o Tree kangeroos eg. Matschie’s tree-kangeroo, Lumholtz’s tree-kangeroo

o Wallabies eg. Red-necked wallaby, agile wallaby – both not much different, very closely related

like possums

up to ~5kg northern NSW, southern QLD lives in rainforests

used to occur in Victoria, but no more

modified hopping ability to enhance it even more – extremely agile

often bask in the morning bright orangey yellow in color bands on tail threatened species (by goats and foxes)

feet still large for a tree dwelling species, though already reduced

PNG species – in PNG Very specialized

very good at climbing tail used for counter balance, not prehensile

down east coast into SA, occurs in Tasmania too

up to 25kg

lives at the top end (Kakadu) and northern QLD

o ‘odd’ wallabies eg. Quokka, Swamp wallaby

o Wallaroos: bigger than wallabies, smaller than kangeroos

eg. Euro, Antilopine wallaroo

o Kangaroos

eg. Red kangaroo, Western grey, Eastern grey – all are around the same size

o sexual dimorphism: heteromorphism males and females differ in shapes growth rate of males much faster than females males

- huge shoulders and arms, big hands and sharp paws – rearranged proportions of body to be bigger in front

o to do with male-male competition: sexual selection o being bigger and having superior fighting ability = increased reproductive

success, therefore selection for such characteristics - color different from females

females: - slightly smaller in size - usually bluey-grey

own genus much smaller, different

dentition no close relatives in group

own genus different breeding technique,

dentition, chromosomes

inland stocky (smaller than kangeroos) shorter limbs spend long time in rocky areas

antelope-like can get quite large Kakadu, wet dry tropics getting rare

rusty colored, may be really read

o locomotion quadruped: increased oxygen consumption the faster the animal moves kangaroo

- may walk using tail as well (pentapedal) - not much increase in oxygen consumption as speed increases when hopping

o reproduction embryonic diapause

- ability of embryo to reach a certain stage and stop developing – embryo divides until 32 cell stage then stop

concurrent asynchronous lactation - supports two young at the same time - two teats, one suckling young at foot outside pouch, one suckling young in pouch - production of two different types of milk - eg. tammar wallaby – high % of carbohydrates and low % of lipids and proteins in

milk when really young as body weight increases, and young is putting on lots of muscles etc. % carbohydrate drops and % lipid and protein increases (protein used to build muscle, enzymes etc. required for quick growth)

have big feet with a big tendon (achilles) in back of legs that stores energy in first hop and released in the next one

hop tendon stretched land stretch released spring off on next hop most energy gotten back after every hop, do not require much energy to go faster

therefore much more efficient than quadruped of same body weight and well adapted to low energy arid environment