Week 9

Question 1

Main function of feathers?

Answer 1

Provide insulation,

Colour and form adaptations through sexual and natural selection,

Enable flight

Question 2

What are the hypothetical stages of feather evolution?

Answer 2

Reptilian scale,

Elongation (solar reflection),

Splitting (enables further elongation/flexibility),

Fraying & pigmentation (Insulation/displays),

Elongation (for flight/balance),

Secondary splits, barbs and hooks (lightening & insulation)

Question 3

What are the different types of feathers?

Answer 3

Contour (covers the body),

Down (insulate - soft, fluffy feather),

Semiplume/filoplume (Structural, hold the other feathers together)

Flight (Stiff, large surface area, overlap to form a continuous flight plain)

Question 4

What are feathers, beaks and claws made out of?

Answer 4

Beta-keratin

Question 5

What are mammalian hair, claws and hooves made out of?

Answer 5

Alpha-keratin

Question 6

What are the different feather tracts on birds?

Answer 6

Capital, Spinal, Crural, Femoral, Humeral, Ventral, Alar, Caudal.

These overlap to cover the skin of the bird, rather than feathers just growing all over the bird

Question 7

Where do primaries vs secondaries feathers grow? What is their role?

Answer 7

Primaries - Outer,

Secondaries - Inner

Both are covered at the base by primary coverts and greater coverts; which creates a solid plane for the bird to fly as well as provide protection

Question 8

How do birds maintain their feathers? (Learned behaviour)

Answer 8

Preen (zips up any feathers that have been dislodged)

Oil (produces water proofing properties)

Bathe in water and dust (Wash out dust, dirt, parasites eg fleas, ticks, lice which can reduce health and pass on disease)

Question 9

How do birds maintain their feathers? (Natural behaviour)

Answer 9

Moult

Feathers usually last a year before they wear out - can’t moult at the same time for every feather, usually occurs after breeding

Start moulting their primaries first and then ones around it, reducing gaps in the wings otherwise it could have negative impacts on their flight

Question 9

Why do birds moult feathers?

Answer 9

Feathers wear out - abrasion, UV​

Mites and parasites​

Change plumage - breeding/​non-breeding​ (survival mechanism - to attract or defend/protect)

Question 9

Examples of moulting variation in birds depending on life style?

Answer 9

Related to flight dependency​

​Swift: 6-7 months, very slow​ (Highly dependent on flight)

Ducks & geese: drop all primaries together (flightless 4 weeks​, as they are not highly flight dependent, they can also swim)

Blue Tit: 65-75 days​

Question 9

How many times has active, flapping flight evolved?

Answer 9

4 times

Insects, Pterosaurs (extinct), Birds, Bats

Question 10

What does active flight require?

Answer 10

Large win surfaces,
High energy (to supply flight),
Very efficient oxygen transport (to burn fuel and enable flight muscles to work)

Question 11

Why does wing shape vary?

Answer 11

Dependent on the way a bird uses flight within its lifestyle.

Eg, Short round wings (pheasants), fast take off, short flight distance.

Eg Long, narrow wings (Swallow), for high manoeuvrability to catch insects,

Etc

Question 12

How to calculate wing aspect ratio?

Answer 12

Wingspan^2 / Wing area

Low = short and round wing,
High = Long and thin

Question 13

What is the average wing aspect ratio?

Answer 13

7

Question 14

High wing aspect ratio versus low wing aspect ratio?

Answer 14

High - Long and thin, good gliders, high speed

Low - Short and round, rapid take-off, higher manoeuvrability

Question 15

What reduces turbulence over a wing?

Answer 15

Alula feathers (Also known as a bastard wing)

Breaks up and controls flow of air over the surface of the wing, allowing speed control, hovering, etc

Question 16

What do wing tip slots allow for? What birds are they usually found on?

Answer 16

Greater control at low speed

Found in large birds with soar a lot eg Cranes, Eagles, Vultures, Buzzards

Question 17

What are the components of bird respiratory system?

Answer 17

Glottis, Trachea, Lungs, Air sacs

Question 18

Inspiration into a bird?

Answer 18

Into the abdominal air sac and caudal thoracic air sac. Moves into neopulmo, where its pushes into the palaeopulmo where air is being pushed out

Question 19

Expiration in a bird?

Answer 19

Air pushed from Palaeopulmo into carnial thoracic air sac and calvicular air sac and then out of the bird

Question 20

Bird respiratory cycle benefits?

Answer 20

Air flows one way over the lungs,

Its continuous and efficient

Question 21

Bird vs mammal lungs?

Answer 21

One-way air flow​

Air pump and gas exchange is separate - so allows thinner exchange surface​

Removes 25% more oxygen per breath​

Efficiency meets high oxygen demand of flight​

Question 21

Kingdom, phylum, subphylum and class of mammals?

Answer 21

Animalia Chordata Vertebrate Mammalia

Question 22

What are the defining characteristics of mammals that are unique to only them?

Answer 22

Mammary glands, Hair, Neocortex, 3 middle ear bones, Single lower jaw bone attached to skull

Question 23

What are the defining characteristics of mammals that have exceptions?

Answer 23

Complex placenta (exception monotremes, marsupials) Endothermy (No exception, also true of birds) Vivipary - giving birth to live young (Exception monotremes (oviparous ie egg-laying) 4 chambered heart (none (also true of birds and crocs)

Question 24

Positive importance of mammals to humanity.

Answer 24

Vital resource – meat, milk, hair, skin​ Service animals, pets​ Hunting​ Ecotourism​ Model species for research incl. medicine​

Question 25

Negative importance of mammals on humanity?

Answer 25

Pests – crops, livestock, household​ Introductions – outcompete or predate on native fauna​ Disease – agriculture, human health​

Question 26

What are the evolutionary origins of mammals?

Answer 26

Evolved from synapsid reptiles​ (cf. sauropsids – dinosaurs & birds)​ - single opening in skull behind eye​

Question 27

When did shrew-like mammals appear?

Answer 27

Small, shrew-like mammals first appear in the Triassic (225-195 mya)​

Question 28

What occurred 100 million years after shrew-like mammals appeared?

Answer 28

(non-avian) dinosaurs extinct​ - marsupial & placental mammals diversify, in the Cenozoic (?)​

Question 29

What are the three major groups of mammals according to the pattern of embryonic development?

Answer 29

- Prototheria (monotremes) = oviparous (primitive reproduction (egg-layers))​ - Metatheria (marsupials) = viviparous but gestation short, pouch development​ - Eutheria (all placentals) = viviparous​

Question 30

What is the current diversity of mammals?

Answer 30

c.6500 species (more?)​ Grouped into 27 orders​ Classification (taxonomy, phylogenetics) changes - almost daily!​ Most major orders remain the same (but the relationship between them often changes)​

Question 31

What are the cetaceans mammals?

Answer 31

Whales / Dolphins The greatest native mammal to Britain

Question 32

Which mammal species is the most diverse of the orders?

Answer 32

Rodentia

Question 33

What is the second most diverse species of mammals?

Answer 33

Chiroptera (bats)

Question 34

What are the major orders of mammals?

Answer 34

Monotremata: Monotremes Diprotodontia: Possums, macropods, wombats, koala Primates: Primates​ Lagomorpha: Lagomorphs​ Rodentia: Rodents​ Eulipotyphla: Shrews, moles, hedgehogs (formerly Insectivora)​ Chiroptera: Bats​ Cetartiodactlya:​ Even-toed ungulates (formerly Artiodactyla)​ Whales, dolphins (formerly Cetacea)​ Perissodactlya: Odd-toed ungulates Carnivora: Carnivores

Question 35

What are features of monotremata mammals? (Monotremes)

Answer 35

Primitive, egg-laying​ 5 species, all in New Guinea & Australia​ Platypus, echidnas​ ‘One opening’: a cloaca​ No nipples​ A spur on the hindleg​ (venomous in male platypuses)​

Question 36

What are features of the Marsupial mammal (comprised of several orders)?

Answer 36

Give birth to poorly developed young​ Young develop in pouch (no complex placenta)​ 7 orders, most in New Guinea & Australia but also the Americas​ Diprotodontia order: ~250 spp.​ Convergent evolution​

Question 37

What is convergent evolution?

Answer 37

Same trait have evolved in two or more species but without any relationship between them. Independent evolution of the same trait.

Question 38

What are features of the Rodentia Mammal (rodents)?

Answer 38

pair of continuously growing incisors in each jaw​ Many herbivorous but some omnivorous​ Most speciose order: ~2500 spp. (c.40%)​ Includes many model species (e.g. lab rats) but also pests​

Question 39

What are features of the lagomorpha mammal (lagomorphs)?

Answer 39

Superficially similar to rodents, but have 2 pairs of incisors in upper jaw & all herbivores​ 2 main groups: hares/rabbits & pikas​ Double digestion – produce 2 types of faeces, 1 of which is reingested​

Question 40

Features of the Primates mammals (primates)?

Answer 40

Distinctive skeletal structure, opposable thumbs, large brains​ Highly ‘intelligent’… advanced cognition (e.g. tool use)​ Comprise of: Prosimians, monkeys, lesser apes (eg gibbons), great apes​ (including homosapians) Hominidae: gorillas, chimps, orangutans, us!​

Question 41

What are features of the eulipotyphla mammals (insectivores)?

Answer 41

Often redefined, but…​ Mostly small, ground-dwelling, usually with a pointed snout​ Insectivorous! But can take small vertebrates​ Include Shrews, hedgehogs, moles​ Others in the group are now placed in other orders incude: Sengis, tenrecs & others now separate​

Question 42

What are features of the chiroptera mammals (bats)?

Answer 42

Forelimbs form webbed wings – flight!​ 2 main groups – large fruit bats & small echolocating bats​ Highly diverse (>1400 spp.); some eat fish, frogs, blood…​ Important disease vectors (e.g. rabies)​

Question 43

What are features of the Carnivora mammal (Carinvores)?

Answer 43

Distinctive skull structure & dentition​ Mostly meat-eaters, but some herbivorous​ (eg Panda) Include: Cats, dogs, mustelids, bears, mongooses, seals​ Most diverse group in terms of size​ Often top predators​

Question 44

What are features of the Ungulates mammals (Two orders... ish)?

Answer 44

Hoofed mammals – walk on tiptoes​ Mostly herbivores, with specialised digestion​ 2 major groups:​ Perissodactyla (odd-toed)​ - horses, tapirs, rhinos​ Artiodactyla (even-toed)​ - pigs, hippos, deer, antelopes, sheep, cattle​

Question 45

What are features of the cetaceans mammals (cetacea)?

Answer 45

Forelimbs modified to flippers, hindlimbs vestigial & not attached​ Aquatic: all oceans, but some freshwater spp.​ Include: Whales, dolphins, porpoises (toothed & baleen)​ Capable of: Echolocation & electroception​

Question 46

Conservation of mammals?

Answer 46

About 27% of all known species at some risk of extinction​ 82+ extinctions in last 500 years​ Major threats = overexploitation, habitat loss & environmental change​

Question 47

What is Anisogamy

Answer 47

The difference in the size of gametes. (Fundamentally, this is the difference between males and females) Females = few, large gametes (eggs): costly Males = tiny, many gametes (sperm): cheap A driving force in shaping reproductive strategies

Question 48

What do females and males want: anisogamy?

Answer 48

Males breeding success: limited by number of eggs fertilised so want quantity Females breeding success: limited by number of young raised, so want quality

Question 49

How does gestation and lactation influence mating systems within mammals?

Answer 49

Gestation and lactation Females are constrained by costly, lengthy development Post copulation, males can move on (no time constraint) Females should focus on quality, males on quantity

Question 50

How does diet, habitat and density influence mating systems within mammals?

Answer 50

Carnivores​ - prey must be hunted​ - paternal care needed​ - females solitary​ - males should stick around​ Herbivores​ - no paternal care needed​ - females in groups​ - males should sleep around​

Question 51

What is monogamy?

Answer 51

1 male, 1 female (exclusive mating)

Question 52

What is polygamy?

Answer 52

(Multiple mating) 1 male, many females = polygyny 1 female, may males = polyandry

Question 53

Anisogamy, gestation and lactation are ubiquitous, so most mammals have a ..... mating system

Answer 53

Polygyny

Question 54

Polygyny in terms of mammal mating systems?

Answer 54

The dominant mammalian system: >90% of spp.​ Takes different forms​ Commonly, males monopolise groups of females (harems)​ ‘Female defence polygyny’​ Male competition leads to adaptations for fighting (e.g. large body size, antlers)​

Question 55

if females cannot be monopolised, (Polygyny) males may try what?

Answer 55

To attract many females. ‘Resource defence polygyny’ (e.g. some bats & ungulates)​ Lek = groups of males display to females who come to mate (not for resources)​ (This is rare in mammals)

Question 56

What occurs in polygyny in mammals if females are dispersed, or unpredictably distributed?

Answer 56

males may move around​ ‘Scramble competition polygyny’ (no male territory or dominance)​ Not common but there are some classic examples​: polar bear, moose

Question 57

Polyandry in mammals?

Answer 57

More common in polytocous (litter-bearing) species - multiple paternity (e.g. some rodents, felids, canids)​ May ensure fertilisation​ Female choice (quality!)​ Reduce risk of infanticide by paternity uncertainty​

Question 58

Many mammal polyandrous species may be polygynandrous, what does this mean?

Answer 58

both sexes have multiple partners​ Both sexes benefit​ This occurs in many primates (e.g. chimpanzees & bonobos)​ And in the very few species of semelparous mammal e.g. brown antechinus​

Question 59

What is a semelparous mammal?

Answer 59

Species that breed once in its life time Eg brown antechinus. Order: Marsupials

Question 60

Monogamy within mammals?

Answer 60

Rare (<5% of spp.) but found in many orders​ Tends to occur in hunting species – where males are needed for offspring care​ May occur when male range covers only one female range (e.g. monotremes)…​ …or at low density (e.g. voles)​

Question 61

What factors promote group living within mammals?

Answer 61

* predation pressure​ * social foraging/hunting​ * thermoregulatory benefits​ * higher breeding success​

Question 62

Solitary social system mammal?

Answer 62

The ancestral state​ (Primitive) Remains a good option if territories/resources are easily defended​ Many top predators are solitary – they only have to hunt for themselves​ (May only come to others when breeding) Found in most orders​

Question 63

Semi-sociality social system, mammals?

Answer 63

Many mammals form temporary groups or come together in certain conditions​ For protection​ For reproduction​ For warmth​

Question 64

Sociality social system, mammals?

Answer 64

Many mammals live in groups year-round​ Composition/stability varies (e.g. ‘fission-fusion’ eg giraffes, dolphins)​ Eat, don’t get eaten​ Direct social interactions, but limited cooperation​ Independent reproduction

Question 65

What is communal breeding in social systems in mammals?

Answer 65

Where stable groups occur, cooperation is often advantageous e.g. hunting in wild dogs​ In some such groups, many or all females breed & offspring care is shared = communal breeding​ Low reproductive skew (Multiple females get to breed,)​

Question 66

What is cooperative breeding within social systems in mammals?

Answer 66

Competition between same-sex individuals may increase reproductive skew​ (Only few individuals get to become dominant breeders) Especially if there are breeding constraints (e.g. food is scarce)​ Young or small (less dominant) females may remain in the group but not breed​ Non-breeders may benefit from helping = cooperative breeding​

Question 67

Where does cooperative breeding occur?

Answer 67

Rare in mammals (< 5% of spp.)​ Restricted to primates, carnivores & rodents​ Often only one female breeds (successfully) Reproductive suppression​ High reproductive skew​ (Small number of individuals reproduce)

Question 68

What is reproductive suppression in mammals?

Answer 68

dominant female suppresses the subordinate female (eg by kicking the other out of the group which leads to abortion or miscarriage)

Question 69

What is eusociality social systems in mammals?

Answer 69

In extreme cases, non-breeding females are sterile (cf. social insects)​ Breeding females (‘queens’) & workers show specialisation​ Very rare (two spp.)​ eg Damaraland mole-rat, Naked mole-rat