Animal behaviour Flashcards

Question

What causes development of sexual dimorphism? ## Footnote Can inc weaponry

Answer 1

Intra- (outcompete rivals) & inter-sexual (be more attractive) selection

Answer 2

Californian elephant seals 4% males responsible for 85% reproductive success, males fight for dominance so dominant males mate far more often. -> reproductive skew BUT can have trade-off -> horn + eye size in beetles, larger weapons sexual beneficial but reduces survival in Soay sheep

Answer 3

Colouration in males, courship displays, elaborate architecture e.g. Bower birds make structures, sticklebacks creates nests

Answer 4

Oral gifts: nutrients to consume e.g. Great Grey Shrike Seminal gifts: protein-rich ejaculate to nourish female e.g. bush crickets

Answer 5

Sexy son hypothesis - females choose males based on producing offspring w/ the best chance of reproducing Zahavi's handicap principle - females choose males because he was able to survive w/ a costly sexual trait (sexual signals are costly, 'honest signal')

Answer 6

Male traits originally indicate survival advantage, genes arise that enable females to detect + chose that trait. -> leads to runaway selection where females prefer longer tails despite fitness cost But no precise genetic basis known for female choice

Answer 7

Males have multiple mates & multiple nests. Andersson (1982) experimentally manipulated tail length to examine if: - Females preferred males w/ longer tails - Tails were costly -> males w/ artificially elongated tails had more active nests Cutting + sticking tail feathers had no effect, low sample size? Then looked to see if tails were costly -> males w/ shorttails in better body condition over time (handicap principle)

Answer 8

Competition between sperm from rival males to fertilise a females eggs - Extended for of male-male competition - Males have numerous strategies for dealing w/ sperm competition

Answer 9

Mate guarding - avoid competition, common in invertebrates Removing rival male sperm during mating e.g. complex male genitalia remove rival sperm in Odonata Increase investment in sperm production

Answer 10

Red Jungle Fowl strategically alocate sperm to maximise reproductive success. - higher investment when presneted w/ novel female Lareg testes: norhtern giant mouse lemur testes 5.5% body vol

Answer 11

Females use physical or chemical mechanisms to control male's success in inseminating her eggs. - red jungle fowl females eject more sperm after mating w/ subordinate males (lower ranking), dependent on social standing

Answer 12

1) Animal's goal is to maximise amount of food it can collect per unit time 2) Strategy is series of independent decisions

Answer 13

Whether an item is included in an animals diet should not depend on how common that item is (no lambda in r2 expression, left), only depends on how common better food types are SO poorer items should be included in the diet only if better items are rare.

Answer 14

Krebs study into Parus major birds (1977): - Worked with large + small mealworms on conveyor belt - Controlled encounter rate + proportion of good/bad food sources When big prey common, took only big prey When big prey rare, took both big + small prey -> predictions qualitatively & quantitatively correct, birds effective at maximising gain per unit time

Answer 15

Yes - shown in J. phaenotus birds - Given same number of seeds on average at each feeder, should use them equally? - 1 feeder always gave exactly same number, other gave variable number When avg. number seeds high, bird chose consistent feeder. When avg. number seeds low, birds always chose more variable feeder. If there are diminishing returns of total reward vs fitness - higher tolerance for risk

Answer 16

Juvenile blue-gilled sunfish are prey fror bass. 1. Adult bluegill foraged open water + grew same rate on both sides 2. Juveniles used open water on bass-free side + foraged in vegetation on side w/ bass 3. Juveniles grew 27% slower in side w/ bass Had to balance foraging habits w/ risk of being eaten (danger) ## Footnote Werner et al, 1983

Answer 17

A. trifolium spider can rush in + bite or wrap it in sil (less risky) Lepidoptera + diptera have probiscus/non-dangerous vs othoptera (crickets) have mandibles (more dangerous) Food type modifies predatory behaviour -> safety prioritised

Answer 18

P. inorta (finch) have independent foraging patterns depending on tree - theory suggests should be 1 optimal approach SO theory does not take into account ability of bird to learn one behaviour very well -> reducing handling time (complicates theory)

Answer 19

Expected number of offspring that an individual will produce over the course of its lifetime. - depends on viability & reproductive success

Answer 20

absolute fitness (W) / population mean fitness

Answer 21

Predation - interaction where fitness of one organism increases, fitness of the other decreases

Answer 22

Mutualism: +/+ Competition: -/- Commensalism: +/0

Answer 23

Ability of an organism to conceal itself especially from a predator by having a colour, pattern, and shape that allows it to blend into the surrounding environment. Can help animals avoid predation

Answer 24

Change in selection pressure (industrial rev) -> selection for carbonaria moth (increased frequency) Pollution now reduced so typica selected for again (morph switching) ## Footnote Crypsis dtermined by env slection pressures (predation)

Answer 25

Yes - resting orientation of moth head on tree affects likelihood of being spotted by predator

Answer 26

Organisms attempt to be mistaken for non-prey, exploits cognitive limitations. vs crypsis where organisms exploit predators sensory limitations (camouflage)

Answer 27

P. cresphontes butterfly Cuttlefish (cephalopods) capable of both

Answer 28

Warning colourations to deter predators due to a toxic trait carried by the organism (honest signal) Can be costly - maintenance + no camouflage so rely on predator learning about toxic trait in past Is maintained in a pop, not selected againts by evol pressures. ## Footnote e.g. black + yellow bees + wasps, brighmonarch butterflies

Answer 29

FALSE - it is density dependent e.g. Spotted bird grasshopper - if individual rare in env, camouflage more beneficial as most predators not aware of toxic trait

Answer 30

- Black/white colouration of skunk -> foul smelling spray - orange/black wings of monarch buterfly -> ingested toxic milkweed (similar to cinnabar moth caterpillars) - yello/black of wasps & bees -> sting

Answer 31

Batesian mimicry - undefended organism mimics well defended model e.g. milksnake benefits (predation as cost for coral snake, left) Mullerian mimicry - both organisms are defended, have evolved similar warnings e.g. hymenoptera (mutualism)

Answer 32

Prey avoids notice in crypsis but is misidentified in masquerade/mimicry (sensory vs congitive systems exploited) Masquerade is a resemblance to an inedible or inanimate object vs mimicry can resemble a trait of another organism to gain a selective advantage SO affects evol dynamics

Answer 33

Males + females have same size flags + wave at same rate. Unaffected by social context so not for sexual selection. In presence of mantis', flags wave vigorously -> mantis attacks legs, falls off allowing matador to escape. (deflection mechanism/sacrifice) Also thought to be an aposematism to birds (warning signal)

Answer 34

Behaviour that increases fitness of offspring (likely to have originated/maintained for this function) ## Footnote Rare in arthropods

Answer 35

Provisioning of energy & nutrients (proteins + lipids) ## Footnote Larger eggs in some species, such as turtles, provide greater nutrient reserves at hatching.

Answer 36

Coat eggs with defensive secretions ## Footnote beetle species.

Answer 37

Mud, plant material, silk, mucus ## Footnote Nest building can vary from simple burying (sea turtles) to elaborate structures (burrows).

Answer 38

Non-random egg laying Seen in mosquitoes + dusky warblers ## Footnote Birds and some fish choose specific sites to maximize survival and minimize predation.

Answer 39

Female grass miner moths ## Footnote They choose sites that may enhance their own survival.

Answer 40

Parents remain with eggs/offspring at a fixed location -> protection from predators, fanning, site maintenance ## Footnote This form of care is common post-natal, e.g., African bullfrogs dig channel to maintain tadpole water source.

Answer 41

Parents carry egg/offspring -> mobile attendance giving protection. Safer than regular attendance ## Footnote e.g. arachnids (giant water bug), marsupials like kangaroos, mouth brooding cichlids (fish develop in males mouth) -> evolved in many variable environments

Answer 42

Offspring provided with a food source after hatching ## Footnote Can be direct (regurgitation in seabirds/beetles, passerines give actual food) or indirect (crowned plovers alert offspring to food source)

Answer 43

Milk (mammals), trophic/unfertilised eggs (poison dart frogs) & matriphagy (some arachnids + earwigs) ## Footnote matriphagy - offspring consume mother

Answer 44

Bewicks swans assist offspring in competition for food Burying beetle larvae nutritionally independent at 72 hours.

Answer 45

Superprecocial - independnet living soon after birth Precocial - relatively mature/mobile at birth Altricial - very young/immature, dependent on parental care after birth ## Footnote largely dependent on ecology + env pressures

Answer 46

Increased predation risk - male pipefish more conspicuous to predators Physiological costs - male cotton top tamarin lose 11% body weight in 3 months >260K to raise a child in the UK

Answer 47

- Improved offspring survival + quality - Costs & benefits differ between species due to ecology, can differ between sexes. Maternal, paternal, bi-parental ## Footnote Each type varies in its ecological context and species.

Answer 48

Monogamy ## Footnote Involves a pair bond between male and female.

Answer 49

Males mate with several females; females mate with a single male ## Footnote This system is commonly linked to maternal care.

Answer 50

A female mates with multiple males ## Footnote Often associated with paternal care.

Answer 51

Oviparous - 90% Most species have altricial chicks - Few sex-specific anatomical/physiological specialisations - Both sexes capable of nest building, incubating, feeding etc. ## Footnote Only 8% have maternal care and 2% have paternal care.

Answer 52

It may be a primitive form of care ## Footnote Supported by fossil records showing paternal care in primitive birds.

Answer 53

Cost of large eggs to females and cost of care ## Footnote Male care may have originated to protect eggs and attract females to territory.

Answer 54

Females always provide care Monotremes - egg incubation in abdominal pouch, no nipples Marsupials - altricial young cared for in a pouch Placental - wide range of female care ## Footnote However, there are exceptions in certain species.

Answer 55

Primates, carnivores + rodents Female care primitive BUT bi-parental thought to evovle 9 times from it ## Footnote The majority exhibit uniparental care, with paternal care being more common than maternal.

Answer 56

Majority have no care - 78% cases uniparental & paternal more common than maternal inc hiding of eggs, nest building + egg/fry protection Male only care evolved 22 times (evolutionarily labile), always lineages w/ external fertilisation ## Footnote This occurs primarily in lineages with external fertilization.

Answer 57

Behaiour that will maximise lifetime reproductive success (LRS) Sex differences in costs + benefits influence probability of care giving. ## Footnote LRS includes success from current and future broods.

Answer 58

Parental investment - sex that invests less in gametes & embryos less concerned about what happens to offspring after mating. Paternity certainty - Males less sure than females that offspring is theirs - males no assurance vs female definite 50% genome - fitness gain from desertion must be greater than from staying ## Footnote The sex investing less in gametes is less concerned about post-mating offspring care. pattern devoid in fish!

Answer 59

- Gamete sizes - Gamete production cost - Reproductive rate - Competition among sex producing small gametes - Males avoid costly parental care to find more mates

Answer 60

- Desertion opportunity - Sexual selection - Paternity certainty - Territory establishment

Answer 61

Higher in males for internally fertilizing species, but not externally fertilising. - mate guarding + know they are only species to fertilise eggs Higher paternity certainty increasing parental investment ## Footnote -> paternal care in fish

Answer 62

Simultaneous gamete release Some Catfish + Gourami males known to release sperm first ## Footnote 36 out of 46 species studied exhibit simultaneous gamete release, often accompanied by monoparental care.

Answer 63

- evidence that females prefer nests w/ eggs already in them e.g. mediterranean blenny - preference for high quality territory in Lake Victoria Cichlids

Answer 64

Thought to be selected for by females. Males defend it w/ eggs & fry when externally fertilised species lay eggs on his territory -> lower cost as aldready defending territory - Enhanced paternity certainty - Increased fitness due to egg/fry protection ## Footnote When survival rates are low with only one parent caring, this can lead to the evolution of biparental care strategies.

Answer 65

Blue gill sunfish Have sneaker phenotype - mature earlier + dart into males territory + fertilise eggs.

Answer 66

Occurs in 1% of bird species ## Footnote Forced adoption happens when chicks are raised by parents that are not their biological mothers, often linked to brood parasitism.

Answer 67

Obligate and facultative ## Footnote Obligate parasites are completely dependent on other species for reproduction, while facultative parasites use parasitism as an alternative reproductive tactic.

Answer 68

Maternal care + polygyny common in seed eaters e.g. savannah weaver birds. - Seasonally abundant food resource , lower cost to uniparental care - Internal fertilization -> male opportunity to desert ○ Male gains more by desertion (LRS depends more on number of matings)

Answer 69

Constraints on offspring survival w/ uniparental care. Can be simulatanoeus or sequential (emperor penguins divide labour in breeding cycle)

Answer 70

Lower sexual selection + sex ratios not skewed (equal)

Answer 71

In Common eider (Sea Duck), 47% chicks not raised by mothers - likely to abandon young if mothers in poor condition Can be adopted: - Gain parental experience - Low costs - High cost to getting it wrong ○ Could kick out your own offspring ○ Ignore begging from own offspring

Answer 72

Forced adoption - occurs in ~1% bird species. ## Footnote Cuckoos & cowbirds

Answer 73

- Obligate - parasite completely dependent - Facultative - parasitism an alternative tactic + supplements parasites own reproduction

Answer 74

Transmission of information from sender to receiver (animal to animal), receiver modifies behaviour in appropriate way. Can be indirect + eavesdropped Can interspecific & degree of co-evolution between sender/receiver Can be honest (ladybird coluring indicates toxicity) or dishonest (mimicry in moth + flies to look like bees/wasps) ## Footnote e.g. hornet moth, hoverfly

Answer 75

Chemicals released that infuence behaviour of other members of same species (intraspecific) e.g. kangaroos to detect fertility in females

Answer 76

Environmental conditions + signal characteristics e.g. chemical signals are long distance but transmitted slowly

Answer 77

Many communication components have been taken from other contexts - used for other purposes, often through sexual selection. e.g. in cranes, courtship dance derived from flying

Answer 78

Signals evolve to increase fitness of sender by altering behaviour of receiver Cues did not evolve this way, despite receiver using them this way ## Footnote Size is a cue, not a sgnal, antlers are signals (costly to produce/maintain)

Answer 79

Internal env: - species, age, group membership, kinship - location - condition/quality - fighting ability - motivation/future actions (e.g. attack) External env: - presence of predator OR food

Answer 80

Low quality males gain large benefit from mimicking high quality males -> mating SO females needs to recognise dishonesty

Answer 81

Reliable signals that are truthful. Costly to send. Cost correlates w/ sender quality. e.g. stotting to demonstrate physical strength in deer - dter predators e.g. male red deer antlers are sign of quality - sexual selection, males also grunt + release pheromones in urine - Larger body, lower frequency - Higher rank, grunt more often

Answer 82

Colour increases predation risk + costly to maintain. -> reamianing alive w/ hindrance indicates strong genetics (Zahavis handicap principle) Colour can also be diet related (good foragers) May also have metabolic tradeoff hindering immune system. ## Footnote Low quality males suffer greater cost than high quality

Answer 83

In blackbirds, can be eavesdropped by other species -> brings attention to predator. Vervet monkeys specialised alarm calls for different predators.

Answer 84

In Passerine birds - indicate dominance - honest signal but not conspicuous Artificially enhanced badge in House Sparrow -> 3.62 attack increase by other males -> intra-species social cost, ## Footnote Also in paper waps - have clypeus patch (similar increased aggression when clypeus enhanced)

Answer 85

Up to 44% regenerated claws in Yucca & Yulipes crabs sp. are large but low quality, good for signalling but bad for fighting Dishonesty more prevalent in lower mean body mass populations ## Footnote Hard to detect

Answer 86

Sneaker fish found in blue-gilled sunfish, cuttlefish & salmon: males mimic females to fertilise eggs in other dominant males territories - Cost of falsely rejecting mates

Answer 87

Predators can lure in prey -> spider tailed horned viper, anglerfish

Answer 88

Movement of an organism away from birth site or population centre to colonise new areas.

Answer 89

Solitary but come together to breed (prolific w/ 10 pups per female) Short maturation time of offspring so would expect exponential pop growth or plateau due to lack of resources BUT instead has fluctuating pop (Greenland arctic tundra)

Answer 90

Migratory behaviours persist despite no selective advantage to individual (not to own death though) Stoats (M. erminea)? BUT gestation too slow + when lemming pop 'turns' ratio lemmings:stoats is highest, lowest predation pressure SO likely predation aggregation: long-tailed skua, stoat, snowy owl + arctic fox - controls lemming dynamics

Answer 91

No dispersal in temporally constant environments. -> individual that moves will have slightly lower fitness than individual that stays ## Footnote Due to carrying capacity of a population

Answer 92

Energetic costs - fewer eggs laid in D. melanogaster after dispersal Investment in dispersal physiology - winged vs wingless cricket (G. assilimilis), treated group invested repossessed energy from wings into ovary production Predation - voles (M. oeconomus) that dispersed died sooner Failure to find new habitat - selection against dispersal in island like systems, continuous vs fragmented feeding patches in butterflies (deaths from dispersal high in fragmented habitats)

Answer 93

Environments rarely temporally constant so carrying capacities likely to change annually.

Answer 94

Metapopulations - group of populations linked by small amounts of dispersal. Individual populations often small -> can go extinct (stochastic element), - but often repopulated, can characterise age of population

Answer 95

Yes it maintains dispersal Dependent on patch/population characteristics e.g. isolation/connectivity

Answer 96

- new invasions - anticipation of env - avoiding inbreeding (depression) Sex-dependent dispersalf favoured by anisogamy

Answer 97

Cane toad intro in Australia - predators (Iguana) not eveolved to deal w/ its toxic defences Toad spread across Australia - toads w/ longer legs moved farther + are in newest patches, started moving in straighter lines -> speed of movement across Australia increased as dispersal ability of toads increased.

Answer 98

S. frugiperda (fall armyworm) - corn pest, very high densities of larvae, larger larvae eat smaller ones (cannibalism) Cannibals better flyers, larger wing/body ratio (dispersal favoured in densely pop environments)

Answer 99

Varied experience of environment between individuals Larger proportions of recessive alleles in inbred populations - more likely to be exposed to negative selection In Eastern meadow vole, individuals in pop w/ siblings more ikely to disperse to avoid inbreeding.

Answer 100

Very sensitive to temperature, use wind to migrate 400-600km a night. - Each female can lay up to 2,000 eggs -> massive pop increase, mass migration

Answer 101

Mexican free-tailed bats (Tadarida brasiliensis), very large numbers 40 mill in May/June to intercept moth migration + feed. Females have high metabolic demand -> lactation + high body temp Communities started living under man made structures, juveniles from bridge roosts bigger than juveniles from cave roosts -> disadvantage to live in high density cave.

Answer 102

Rendell -> copying is beneficial BUT this omits competition Reawrd from patch is shared so crowded patches less beneficial.

Answer 103

If patches are even or changing rapidly then there is little benefit in copying. However if patches are stable but very uneven then acquiring info from other individuals (copying) is good. e.g. rats livie in heterogenous env (garbage is food source) so copying useful vs goats in homogenous env so copying not beneficial ## Footnote Smolla et al 2015

Answer 104

NO Groups of prey will attract predators e.g. Brown bear intercepts salmon when aggregated during migration Predation makes group living (density costly) -> red spider mite attacked by predatory mite

Answer 105

Selfish herd theory Predator satiation Reduced vigilance Predator confusion

Answer 106

Herding together minimises individual risk of predation, not beneficial to the wider group but the individual instead - as group more conspicuous. e.g. Redshanks more commonly targeted by Hawks were furthest from nearest neighours ## Footnote Hamilton 1971

Answer 107

Magicicada sp. eggs hatch + nymphs burrow into ground around tree roots + remain for ~17 years. Very little interbreeding between broods - spatially distinct. If cicada at very high densities, birds will gorge themselves + rest of high density group will survive - birds can only eat fixed amount. (skins + wings counted) ## Footnote 17 year cycle prevents predator aggregation

Answer 108

Can spend more time eating than looking around for predators. Supported by scan frequency + group size in Goa & Blesboks HOWEVER increased foraging time may be due to increased competition for food -> reduced vigilance cost fo living in group

Answer 109

Class Aves ## Footnote Includes approximately 4000 to 9000 species.

Answer 110

Short and simple vocalization that signals flight or danger, produced throughout the year.

Answer 111

Long and complex vocalization produced during breeding season. ## Footnote More than one version of a song type is a repertoire

Answer 112

Notes/elements: simple continuous narrow frequency band, complex frequency amplitude Syllables: 2 or more notes clustered together Phrases: 2 or more syllable clustered together - can also be series of singe notes

Answer 113

Specific ordering and timing of different elements.

Answer 114

Spectrograms.

Answer 115

Diverse habitats leading to different dialects between areas.

Answer 116

Usually males, due to competition to breed. Both female choice + male/male competition have driven song evolution ## Footnote Twin selectuve pressures

Answer 117

* Long rattle (more testosterone) * Low frequency (better condition)

Answer 118

Complex song. - difficult to fake (quality signal) - may idiciate age/maturity ## Footnote Correlated w/ mating success in great tits, great reed warblers + song sparrows.

Answer 119

* Presence of potential mate * Individual identity * Birth and raising location * Physical location * Territory ownership * Willingness to breed * Condition * Early environmental experience

Answer 120

Rambling sounds variable in time and pattern.

Answer 121

Assumes posture and produces sounds in discrete clusters with detectable temporal patterning.

Answer 122

Full song expressed with normal variation in volume, duration, and syllabic structure.

Answer 123

* Sensory phase * Sensorimotor phase * Transition to crystallized song

Answer 124

Auditory experience where the song must be exposed to and committed to memory.

Answer 125

Involves vocal practice and includes both subsong and plastic song stages.

Answer 126

* Seasonal closed learners * Age-limited learners * Open-ended learners

Answer 127

Innate predisposition to learn songs of conspecifics, limited learning window using auditory stimuli. Song genetically encoded but environment + learning significantly enhances

Answer 128

Regional variation in song stages at different ages. Coast vs Montane birds. -> ecology/habitat of bird impacts on birdsong learning

Answer 129

Swamp sparrow (M. georgiano) & Song sparrow (M. melodio)

Answer 130

Swamp sparrows combine models of both species - learning involves soft/plastic template - When crystallizes, decrease in syllable sounds (stabilisation VS in white-crowned sparrows - adult song does not contain heterospecific components.

Answer 131

Testosterone undergoes seasonal changes. Inhibits plasticity, functions to crystallize songs. ○ If administered early, will cause premature crystallization ○ In castrated males, songs never crystallize

Answer 132

They are involved in the neural circuitry of song production. - Higher vocal centre (HVc) - Robust nucleus of archistriatum (RA) - Tracheosyringeal portion of hypoglossal nucleus

Answer 133

- testosterone injected females will sing + increased vol of HVc & RA - adult male canaries HVC & PA are 99% & 76% larger in spring than in autumn. - neurogenesis in HVc of adult canary when learning new seasonal song

Answer 134

True When HVc lesioned, cannot produce WT song

Answer 135

- Area X - Medial portion of dorsolateral thalamus (DLM) - Lateral portion of magnocellular nucleus of the anterior neostriatum (LMAN)

Answer 136

High: sebra finch + canary Low: bay wren + buff-breasted wren ## Footnote Correlates to volume of HVc

Answer 137

Social system where individuals provide care for offspring that are not their own at cost of their own reproduction. ## Footnote Examples include meerkats (single breeder in large colony), starlings (sibling help raise young), and naked mole rats (queen + subservient colony).

Answer 138

~300 species of birds (3%), ~120 species of mammals (2%), ~30 species fish (0.1%) - But extensively studied Long-tailed tits are co-operative breeders in UK. ## Footnote Approximately 300 species of birds exhibit cooperative breeding.

Answer 139

Usually 1 male + 1 female breeders with 1 or more non-reproductive helpers. Helpers can be related or unrelated to the breeders.

Answer 140

Helping evolved via kin selection where helpers help relatives, leading to inclusive fitness benefits. ## Footnote This ensures that helpers are more likely to assist those they are genetically related to.

Answer 141

Promiscuity reduces offspring relatedness and certainty of offspring. ## Footnote Lower promiscuity leads to higher relatedness and more common helping behavior.

Answer 142

Life history constraints: * Delayed maturity * Low adult mortality * Non-limited dispersal * Low reproductive rate Ecological constraints: *Territory shortage * Mate shortage * High dispersal cost * Low independent breeding success ## Footnote These factors contribute to the likelihood of cooperative breeding in a species - helpers have littlpe opportunity to breed on their own.

Answer 143

Seychelles warbler intorduced to new island. Cooperation started only after all territories were taken. ## Footnote This model shows that cooperative breeding can emerge when individuals have no other breeding options.

Answer 144

- Both breeders removed -> 0% male helpers moved - Only breeder male removed -> 96% male helpers moved - Mix of cooperative groups & monogamous pairs, ## Footnote This indicates the dependency of helpers on the presence of breeding pairs.

Answer 145

Helpers work harder for refuge access, which provides direct fitness benefits. ## Footnote This theory highlights the trade-offs helpers make for group membership.

Answer 146

Benefit by helping relatives - close relatedness increases help provided. Increases propagation of related alleles. Long tailed tit: failed breeders often become helpers, 94% chose to helps nests of relatives

Answer 147

Significantly reduced offspring raised and food brought in Florida Scrub Jay and African cichlid fish. Increased food due to helpers and not territory quality. ## Footnote This experiment demonstrates the importance of helpers in reproductive success.

Answer 148

breeding ## Footnote This experience can lead to improved reproductive success when they eventually breed.

Answer 149

* Level of relatedness * Competitive ability * Constraints on independent breeding * Reproductive skew models i.e. contest ## Footnote These factors influence whether helpers can participate in breeding.

Answer 150

Direct benefit of helping. Clownfish - local helpers improve chance of taking over territory if vacancy opens

Answer 151

Breeders offer incentives to helper to stay, more required if unrelated or lots of good territories around e.g. acorn woodpecker - breeders concede more reproduction when more vacancies available

Answer 152

Helpers opt out of reproduction, IF only relatives around or serious breeding punishments e.g. meerkats - females breed more when unrelated males in group

Answer 153

Resource and predation related factors ## Footnote Group living can help with resource availability and reduce predation risks.

Answer 154

Increased competition vs predation risk ## Footnote A balance is required to maximize fitness in social groups.

Answer 155

Predation risk decreases & competition increases with group size ## Footnote Intermediate group sizes are associated with higher fitness.

Answer 156

Fecal glucocorticoids (stress hormones), daily travel distance ## Footnote These variables help assess stress and resource availability.

Answer 157

Resource competition - Dominance hierarchies occur where individuals can monopolise resources - More egalitarian groups occur where individuals cannot monopolise (e.g. Howler monkeys), small groups more successful

Answer 158

Lower rank = higher heart rate and blood pressure ## Footnote Stress is linked to health and elevated glucocorticoids.

Answer 159

Group becomes less aggressive; HR/BP decreases ## Footnote This indicates that social structure affects individual stress levels.

Answer 160

Competition where individuals compete for resources without direct confrontation ## Footnote It leads to decreased immune function and reproduction.

Answer 161

Intervention and reconciliation ## Footnote Social behaviors can help manage stress and conflict.

Answer 162

Barbary macaques ## Footnote Mid-rank individuals are often the most stressed.

Answer 163

Increased neocortex ratio correlates with group size ## Footnote This suggests cognitive demands increase with larger groups.

Answer 164

- In Kaimanawa horses in NZ - females more integrated in their social groups have better reproductive success than those that are poorly integrated. - In Amboseli baboons - females that have stronger bonds live longer & have more babied. ## Footnote Females with stronger social bonds have better reproductive outcomes.

Answer 165

Matriarchs remain together + form strong bond, improve foraging success of the group ## Footnote Their presence enhances group survival and resource acquisition.

Answer 166

Less well adapted to distinguishing between male and female lions ## Footnote Older matriarchs have more experience, enhancing group safety.

Answer 167

Release of endorphins ## Footnote Reward centres pirmed by social behaviour.

Answer 168

64,000 km ## Footnote This distance highlights the extensive migratory patterns of certain bird species.

Answer 169

Regular movement back and forth between two relatively distinct locations by animals that use resources concentrated in these different sites ## Footnote Reference: Alcock, 2013.

Answer 170

* Pilotage - steering a course using a familiar landmarks * Compass orientation - ability to head in a particular compass direction without reference or landmarks * True navigation - ability to orientate toward a goal such as home/breeding area/ without use of landmarks + regardless of its direction e.g. Reed warblers ## Footnote These orientations help animals navigate during their migratory journeys.

Answer 171

Three separate times or alternatively has been lost from all other species ## Footnote This indicates the complexity of evolutionary adaptations related to migration.

Answer 172

* Extra weight must be carried to build sufficient energy reserves * Temporary atrophy of reproductive organs * Increased muscle contraction efficiency * Altered metabolism enabling fat storage * Risk of death during the trip * Need to be well adapted to multiple habitats ## Footnote These costs can significantly impact the survival and reproductive success of migratory species.

Answer 173

Those with ample energy reserves took a direct route over the Gulf of Mexico, while those with low energy took an indirect route ## Footnote This illustrates the importance of physical condition in migratory decisions.

Answer 174

- In N. America summer, abundance of protein-rich insects + longer day lengths than tropics - enhanced feeding for birds - Cyprinid fishes migrate over winter to low predation habitats when feeding opportunities are reduced - Monarch butterflies migrate to Mexico to roost over winter - too cold in N. America so will freeze ## Footnote Migration increases fitness

Answer 175

Used to measure pre-migratory restlessness in birds and their orientation in a particular compass direction depending on the time of year ## Footnote This experimental setup is used to study migratory behavior in the lab.

Answer 176

* Visual * Olfactory * Atmospheric pressure * Sound * Geomagnetism ## Footnote These cues provide critical information for animals during migration.

Answer 177

At a given time of day and year, the sun's position provides compass information ## Footnote This method is utilized by various species, including starlings.

Answer 178

Starlings use the sun for navigation and those with phase-shifted endogenous diurnal clocks misinterpret the direction of the sun ## Footnote This study highlights the importance of circadian rhythms in navigation.

Answer 179

* Frogs * Butterflies * Turtles * Lizards * Rodents ## Footnote This suggests a widespread adaptation for using solar cues in navigation across species.

Answer 180

Pigeons showed a higher percentage of getting lost when olfaction was impaired compared to the control group ## Footnote This indicates that olfactory cues play a significant role in their navigation.

Answer 181

They can find their way back to Ascension Island if released north but not south, although the mechanisms are unclear ## Footnote This suggests complex navigation abilities that are not yet fully understood.

Answer 182

Experiments found no evidence of sensing magnetic field in pigeons ## Footnote This suggests that initial hypotheses about pigeons' magnetic sensing capabilities were incorrect.

Answer 183

Data from Emlen's funnel gives evidence that birds have magnetic sense ## Footnote Emlen's funnel experiments demonstrated the ability of birds to orient using geomagnetic cues.

Answer 184

It includes an ink pad, wire screen, and spring ## Footnote These components are part of the experimental setup used to assess bird orientation.

Answer 185

In the ophthalmic branch of the trigeminal nerve in the pigeon bill ## Footnote This discovery highlighted a physiological basis for magnetic sensing in birds.

Answer 186

They cannot orient using geomagnetic cues ## Footnote This suggests that the magnetic sense is localized to the right eye.

Answer 187

Geomagnetic cues ## Footnote This indicates that not only birds but also insects have evolved mechanisms to navigate using Earth’s magnetic field.

Answer 188

Inclination magnetic compass ## Footnote This adaptation aids their autumn migration over long distances.

Answer 189

They orient to stellar cues at night ## Footnote This behavior is critical for their navigation during migration.

Answer 190

They could not orient properly for migration ## Footnote This implies that exposure to the night sky is crucial for developing migratory skills.

Answer 191

They calibrated using cues at twilight ## Footnote This shows that birds can adjust their navigation based on available environmental cues.

Answer 192

A navigation method to calculate their position relative to a starting point ## Footnote This method allows ants to return to their nest after foraging.

Answer 193

Polarised light ## Footnote This ability is also seen in various species including birds, fish, reptiles, and arthropods.

Answer 194

They orient using polarised moonlight ## Footnote This adaptation helps them find their way in the dark.

Answer 195

Individuals must constantly record and report information ## Footnote This is essential for effective navigation in complex environments.

Answer 196

Adults compensated for the displacement; juveniles flew blindly south ## Footnote This suggests differences in learned migratory behavior between age groups.

Answer 197

That the continental map is learned in these birds ## Footnote This reflects the importance of learning in developing navigation skills.

Answer 198

Cooperative behaviours involve an individual paying a cost to give a benefit to a recipient, increasing their fitness.

Answer 199

Natural selection should favour genes that increase individual fitness, leading to selfish behaviours dominating over altruistic ones.

Answer 200

It refers to a situation where everyone would benefit from increased cooperation, but individuals gain massive benefits from being selfish, leading to widespread selfishness.

Answer 201

Direct benefits occur when the reproductive success of the cooperator is increased.

Answer 202

Direct reciprocity requires repeated interactions where both individuals involved have increased fitness and memory of past interactions.

Answer 203

Cleaner wrasse cleans parasites from larger fish; wrasse gets a meal while larger fish have ectoparasites removed.

Answer 204

Indirect benefits occur when the reproductive success of individuals sharing the cooperators' genes is increased.

Answer 205

Altruistic behaviours involve a cooperator paying a cost with no self-benefit to fitness.

Answer 206

Vampire bats share blood with individuals not successful in finding food, typically between pairs or relatives.

Answer 207

Individuals cooperate on the first interaction, and in subsequent interactions, they copy the behaviour of the other individual.

Answer 208

Cooperative genes should increase in frequency when benefits (B) of cooperating are greater than costs (C), considering the level of relatedness (r).

Answer 209

It signifies that cooperative behaviour is favoured when the benefits of cooperation outweigh the costs, adjusted for genetic relatedness.

Answer 210

Kin selection is the process by which traits are favoured due to their beneficial effects on the fitness of relatives.

Answer 211

recognise relatives

Answer 212

Cooperators gain reputational benefits, making altruism worthwhile in the long term.

Answer 213

Memory of past interactions is crucial for recognizing and reciprocating cooperative behaviour.

Answer 214

Tiger salamanders can develop as cannibals or invertebrate feeders.

Answer 215

Larvae were divided into groups with: 1) Siblings only, 2) Siblings and cousins, 3) Siblings and non-kin, 4) Siblings, cousins, and non-kin.

Answer 216

The mean age (days) of cannibal morphology expression varies with different levels of relatedness.

Answer 217

Full siblings spent more time shoaling together and swam closer together than half siblings.

Answer 218

1) Environmental cues: familiarity or shared environment, 2) Phenotype & self-referent matching, 3) 'Green-beard' effects.

Answer 219

If nest mates are switched, non-related birds treat each other as relatives, learning who should be relatives, not who is actually related.

Answer 220

Non-kin were investigated sooner and longer, indicating a self-referent mechanism.

Answer 221

Courtship in turkeys where males court alone or in coalitions with a dominant and subordinate male.

Answer 222

The net benefit of a subordinate male is +1.7 offspring.

Answer 223

When put into Hamilton's rule: (B-C) = (0.42 - 0.9) = +1.7.

Answer 224

Planning and use of tools ## Footnote These behaviors indicate problem-solving and innovation abilities.

Answer 225

Corvidae family (crows, jays), parrots, cephalopods, great apes (chimps) ## Footnote These groups have shown significant cognitive abilities.

Answer 226

Using brain size as a proxy ## Footnote Larger brains in carnivores are often associated with better puzzle-solving skills.

Answer 227

Blue tits pecking through foil caps of milk bottles ## Footnote This behavior is learned socially rather than genetically encoded.

Answer 228

Social complexity drives the evolution of intelligence ## Footnote It posits that challenges of social living lead to increased cognitive abilities.

Answer 229

Group size correlates with relative neocortex size ## Footnote This correlation suggests that larger social groups may require greater cognitive skills.

Answer 230

Diet rather than group size ## Footnote This complicates direct comparisons of intelligence across different species.

Answer 231

Awareness of self or consciousness ## Footnote This is often tested through mirror recognition tests.

Answer 232

Higher levels of mark-directed responses with a mirror ## Footnote This suggests that self-recognition evolved in apes but not all primates.

Answer 233

Dolphins and Asian elephants ## Footnote These species also exhibit behaviors indicative of self-awareness.

Answer 234

Strong responses to gold badges but not to black ones ## Footnote This indicates a level of recognition and distinction in their perception.

Answer 235

Throat scraping behaviors after a marker was added ## Footnote This behavior suggests recognition of self in a way that resembles parasite interactions.

Answer 236

Behaviors changed, but no mark was applied ## Footnote This suggests some level of self-awareness, though evidence is less direct.

Answer 237

Thought to be uniquely huan - awareness of different perspectives/feelings. Scrub jays try to avoid other birds seeing them store their food - apparent intelligence or theory of mind? Testing in animals 2 containers - grasped or accidentally touched -> primates interested in intentional behaviour. BUT may just be good observers of hand gestures - Primates can use info about environmental constraints

Answer 238

Economists argue that we are self-interested (game-theory models) BUT data support humans have a moral framework + show inequality aversion. Capuchins show awareness of inequality - observes other individual being fed grapes not cucumber after same task.

Answer 239

Reproductive behaviour among sexually active males & females -> evolutionary differences between monogamous + polygamous animals

Answer 240

Differential investment - sex that invests more is limiting resource -> polygyny favoured - polyandry occurs in poor quality env (co-op breeding) Ecological factors - if resources are clumped + defensible -> high polygamy potential Paternity certainty - can lead to monogamy if males guard mates Dependence of young - parental care required vs reproductive success for increasing fitness dtermines whether it is better to have more mates or not

Answer 241

Secondary sexual characteristics -> intra & inter-sexual competition. e.g. bright plumage of male birds, the antlers of male deer, or the manes of male lions

Answer 242

A pattern of mating in which a male animal has more than one female mate

Answer 243

Female defence, resource defence, scramble competition, lek.

Answer 244

Grevy's zebra defends areas where females congregate Pains zebra defends females from rival males - females congregate (anti-predation)

Answer 245

Females & resources not always defendable. If females widely dispersed, males scramble to find as many mates as possible. e.g. male thirteen-lined ground squirrel search for mates over few weeks of mating period

Answer 246

Associated w/ extreme traits: e.g. Hammerhead bat evolved large cavern in head, males congregate around trees + make loud noise -> attracts females Lek - aggregation of males that display to females, females do not gen any resources (only there to mates)

Answer 247

Males increase chances by having extreme sexually selected phenotypes/behaviours. Females have a pick of males -> can source high quality genes. Unclear for subordinate males - one dominant male white-bearded manakin had 75% of copulations ## Footnote Reproductive success skewed in leks. Subordinate males thought to be younger

Answer 248

Hotspot hypothesis: males cluster around routes or places frequented by females. Ev: 4 bird species (2 manakins, flycatcher + hummingbird) in Costa Rica used same location to lek -> topology determines female location Hotshot hypothesis: subordinate males gather around attractive dominant males. Ev: Removing dominant male European Sandpiper -> subordinates dispersed, but subordinate removal did nothing. Female preference hypothesis: males cluster because females prefer sites w/ larger groups of males Closely linked to other 2.

Answer 249

3% mammals, 90% birds, ~1% fish

Answer 250

Monogamy is adaptive (more offspring) when females left by one male readily mates w/ another - Beneficial when females remain receptive after mating + difficult to locate e.g. crown shrimp - Better to keep what you have than go looking for another inaccessible female

Answer 251

Monogamy adaptive when parental care greatly increases offspring survival, often in altricial species. e.g. reproductive success of californian mouse higher if he stays to help rear young

Answer 252

Burying beetles, male + females bury carcass which females lay eggs on. Males try attract another female using pheromones, but 1st female detects these + attacks male -> he stops releasing pheromones. - Nature of resource grants female control over mating

Answer 253

- Egg in nest balances relative investment of both males & females - Rearing altricial offspring requires extra parental care ## Footnote But most species are promiscuous (genetical tools) - engage in extra-pair copulations (EPCs) despite social monogamy

Answer 254

Changes in behaviour following experience that are not due to maturational growth processes, fatigue or sensory adaptation -> mechanistically is strengthening of a synapse

Answer 255

Animals stop responding to repeated stimuli - no reinforcement Kandel used repeated stimulation in aplysia (sea slug) via tactile stimuli. -> less effective Ca2+ channels ## Footnote Non-associative

Answer 256

Simultaneous presentation of touch & shock, animal becomes highly sensitive to touch - same network for that of habituation. e.g. Rats behaviour shifts after delivering offspring (parturition) -> maternal behaviour, more likely to pick up pups - sensitisation response to pup odour

Answer 257

Physical basis of memory, due to patterns of synapses e.g. olfactory memories in insect brain stored in muschroom bodies

Answer 258

Genetic basis of circadian rhythms, learning & phototaxis Dunce mutants in flies had learning + memory deficiencies - odour/shock conditioning experiment Dunce controls recycling of cAMP -> AMP - important for memory/learning pathways e.g. ARM ## Footnote ARM - anaethesia resistance memory Gave behavioural, anatomicla + biochemical insights + fits w/ aplysia data

Answer 259

Salivation responses to bell ringing/feeding in dogs -> associative mechanism

Answer 260

Males defend territory from other males. Experimentally conditioned males by announcing arrival of gravid females (about to lay eggs) using buzzer. Conditioned fish -> less aggressive, built nests more, spawned quicker (reduced competition) & produced more offspring - fitness advantage to learning

Answer 261

Aposematism e.g. harlequin ladybirds, monarch butterfly caterpillar produces alkali (toxic) - Predator learning (associate colour w/ foul taste/toxicity) has led to selective advantage of aposematism - This preference not found inherently in birds -> learning indirectly led to mimicry

Answer 262

Bombardier beetle relies on defence (chemical release) upon predation by frog - relies colouration & learning ability of its predators to avoid predation

Answer 263

Animals link stimulus to response after 1 trial. Taste & nausea linked easily, sound & shock also linked easily - but little crossover between 2 pairs - Selective benefit of specific associations (avoiding toxic foods OR predation)

Answer 264

In lab - Skinner box gives active form of classical conditioning w/ food vs electric shock In field - blue tits pecked holes into foil caps to access cream -> spread through pop via social learning/copying

Answer 265

Honeybees - trained to complete tasks for food reward - w/ human demonstrator ~99% bees learnt to complete task Macaques in Japan wash sweet potatoes left on beach by researchers - spread through pop by social learning, younger animals learn better than older

Answer 266

Non-genetic inheritance of behaviours, customs + norms. No purpose/benefit for Chimp to put grass in ear but copied by others (persisted)

Answer 267

Sultan chimp tied 2 sticks together to retrieve food. Crates stacked to reach bananas Vs pigeons which can show beahviour but no insight used (needs to be pre-learnt)

Answer 268

Store seeds, successful in spatial taks but no non-spatial SO learning context specific to animals ecology -> may indicate some fitness cost to learning

Answer 269

More you learn, quicker you die -> strongly suggests cost of learning in drosophila

Answer 270

Rapidly reversible state of immobility & greatly reduced responsiveness, homeostatically regulated such that lost sleep is made up with an increased sleep drive. ## Footnote (Siegel, 2008)

Answer 271

Pattern of specific brain wave activity, associated w/ overall decrease in neuronal activity -> NOT global turning down - Series of precisely controlled brain states - Sequence determined by activity of specific brain nuclei

Answer 272

Basic homeostatic need that increases w/ time awake. - duration + pattern changes w/ age - bout duration increases w/ organism size - critic for normal cog function (rodent fatality w/ no sleep after 2 weeks)

Answer 273

Ecological: - predation - mating - thermoregulation - need to forage Intrinsic: - memory consolidation - energy conservation - metabolic clearance

Answer 274

Electroencephalogram (EEG) - provides continuous recording of brain activity, important tool in lab and clinic -> localises epileptiform activity, mapping - Cheap - Non-invasive ## Footnote Categorise cognitive sleep states using amplitude & period/frequency

Answer 275

- Alpha: most prominent when eyes closed - Beta: associated w/ being alert, attentive & actively thinking - Stages 2-4 are slow wave sleep (SWS) or non-rapid eye movement (NREM) - REM sleep is also known as paradoxical sleep -> high freq, low amplitude, associated w/ dreaming

Answer 276

EEG recordings showed sleep consists of number of stages that occur in characteristic sequence. 1st hour is NREM followed by REM: - SWS/NREM & delata activity (>50% deep sleep) - REM ## Footnote Kleitman & Aserinsky

Answer 277

5 - REM duration increases/SWS decreases throughout sleep bout - deep sleep (IV) only in 1st 2 cycles ## Footnote SWS - slow wave sleep REM - rapid eye movement

Answer 278

Eye movement - electrooculogram (EOG), mainly during REM Neck movement - electromyogram (EMG), waking + REM transitions Heart rate & respiration peak during REM

Answer 279

Rats nocturnal so sleep in day, shorter boyts of sleep + more frequent transitions wake -> NREM -> REM

Answer 280

Interaction between homeostatic sleep pressure & internal circadian clock Circadian component suppresses sleep drive in afternoon to maintain wakefulness.

Answer 281

- Forebrain system independently supports SWS - Brainstem systems activate forebrain into waking & trigger REM sleep ## Footnote Identified by nerve transection studies (Bremer) in cats -> sleep controlled at brain level Brainstem transect -> constant SWS, no REM sleep

Answer 282

Different cell populations in brain that send projections inducing wakefulness. Lateral hypothalamus (LH) - orexin Tubermamillary nucleus (TMN) - histamine (anti-his pills make u feel drowsy), allergies Dorsal raphe (DR) - serotonin Locus coeruleus (LC)- oradrenaline ## Footnote Methamphetamines & ecstasy promote wakefulness by altering chemical levels

Answer 283

Produced by neurons on lateral hypothalamus. - project across brain - signal through Oc1R & Ox2Rs in target regions ## Footnote Orexin KO show reduced wakefulness/increased SWS/REM -> promotes wake.

Answer 284

Sleep disorder: - Excessive daytime sleepiness w/ irresistible sleep attacks - Cataplexy (episodes of paralysis/weakness preceded by strong emotions) - Sleep paralysis - Hypnagogic hallucinations (dream like images at sleep onset) ## Footnote 1 in 2000, appears 15-30yrs.

Answer 285

Reduced orexin neurons found in post-mortem narcoleptic brains -> reduced orexin signalling. (also seen in dogs e.g. labradors)

Answer 286

Sleep w/ half of brain at a time - in aquatic animals & birds

Answer 287

Can sleep w/ one eye open (1 hemisphere awake) When left eye closed (right hemisphere sleeping), vice versa -> decussation - Allows detection of predators during unihemispheric SWS (USWS) - Increase USWS use as risk predation increases - Bihemispheric sleep when predation risk is low ## Footnote Ducks on edge of row hgiher predation risk so more unihermispheric sleep

Answer 288

Primarily rely on soaring-gliding strategy -> circular rising on thermal air currents (soaring). Used EEG to look at head position during wake & sleep. - During flight, SWS associated w/ tilted head - Sleep only occurs during ascending flight - Awake hemisphere is always opposite to direction of rotation (prevent collisions?) ## Footnote During flight, 95% time awake (only small amount of SWS) - most sleep during flight is ASWS and on land sleep is far more bihemispheric.

Answer 289

Autralian dragon EEG & analysis of closed eyes -> regularly occurring episodes of REM, cycles take ~80s in this species

Answer 290

- Period of quiescence associated w/ species specific posture - Increased arousal threshold - Quick reversibility to wakefulness - Homeostasis ## Footnote e.g. flies have preferred resting position + posture, have greater arousal threshold when resting + deprivation causes rebound rest (homeostatic)

Answer 291

Described 1983 - now known in D. melanogaster, scorpions, honey bees & cockroaches. In honey bees: learning, memory, waggle-dance precision & navigational memory reduced by sleep deprivation. There is conservation of neurochemistry that control sleep-wake cycles between many species. -> drosophila can be used for sleep studies

Answer 292

1. Passively/retroactively 2. Proactively

Answer 293

To regulate internal conditions at a set/optimal point in response to environmental changes

Answer 294

Controlling physiology and behaviour variations from day to night

Answer 295

24.5-hour cycles that are a ubiquitous control feature of physiology and behaviour

Answer 296

* Body temperature * Hormone secretion * Sleep

Answer 297

It must be present in the absence of any external cues

Answer 298

A near 24-hour free-running rhythm

Answer 299

Activity slowly synchronises to the new cycle over multiple days

Answer 300

They anticipate changes, such as body temperature rising during the day and dropping before night.

Answer 301

Crepuscular activity, being active at twilight

Answer 302

They still show rhythmic calling, approximately every 26 hours.

Answer 303

It is the main mammalian circadian clock and acts as a pacemaker.

Answer 304

Irregular bouts of activity, indicating the necessity of SCN for circadian rhythmicity

Answer 305

It restores rhythmic behaviour.

Answer 306

Sleep rhythms become disrupted.

Answer 307

Rhythmic activity in metabolic processes, with low activity at night.

Answer 308

They exhibited synchronous rhythmic activity when recorded in intact SCN tissue.

Answer 309

A transcriptional/translational feedback loop comprising stimulatory elements (CLOCK/BMAL1) and inhibitory elements (PERIOD/CRYPTOCHROME) ## Footnote These elements refine the period of the clock cycle to 24 hours.

Answer 310

In cyanobacteria and plants ## Footnote Similar genes have evolved three distinct times.

Answer 311

Using transgenic mice that carry a bioluminescent reporter of clock gene activity ## Footnote Heterozygous PER2::LUC KI mice are used to observe diurnal expression of molecular clock genes.

Answer 312

SCN receives light information via the retinohypothalamic tract (RHT) ## Footnote The SCN is optimally positioned to receive retinal input from the optic chiasm.

Answer 313

Puts cells into a daytime state in vivo ## Footnote This is an example of acute adaptation.

Answer 314

Coupling and effector mechanisms ## Footnote Increased neuronal signaling and endocrine signaling are involved.

Answer 315

Regulates release from the Pineal Gland in response to light and circadian signals ## Footnote Melatonin is released at night in both nocturnal and diurnal animals.

Answer 316

Light rapidly suppresses melatonin release ## Footnote SCN signaling inhibits production/secretion via a multi-synaptic SCN-Pineal pathway.

Answer 317

High mortality rate after 2 months compared to controls and sham-lesioned individuals ## Footnote This indicates the importance of SCN in survival.

Answer 318

Reduced evolutionary fitness due to internal clock speed deviating from environmental rhythms ## Footnote This leads to a lower reproductive rate.

Answer 319

Rhythms that operate over less than 24 hours ## Footnote Examples include human sleep cycles and pulsatile growth hormone release every 3 hours.

Answer 320

Long period rhythms greater than 28 hours ## Footnote Examples include bird migration and reproductive cycles.

Answer 321

Hibernation of the golden-mantled ground squirrel ## Footnote Hibernates from October to May, consistent without external cues.

Answer 322

Length of coat increases in winter, size of testes and prolactin production increases in summer ## Footnote These changes are independent of external signals and regulated by melatonin rhythm.

Answer 323

Pituitary pars tuberalis via melatonin rhythm ## Footnote This encodes day length and drives seasonal changes.

Answer 324

No, it is not fully understood.

Answer 325