Behaviour and ecology- Davies

Semelparity

'big bang' reproduction, where animals reproduce once with a large effort and then die e.g brown antechinus, mayflies, pacific salmon

Proximate

'how' questions, so how the physiology of an organism causes it to behave in a certain way. Includes ontogeny and mechanical.

Ultimate

'why' questions, so why an animal presently has a behaviour due to the process of natural selection and its evolutionary history. Includes adaptive and phylogenetic questions.

egg mimicry reduces host rejection

Darwin hypothesis for parasite egg mimicry

selfish herd theory where frogs surround a pond with a snake. Frogs would aim to minimise their zone of danger.

Hamilton's frogs

conflict between siblings in present and later broods (weaning conflict often in seals)

Interbrood conflict

conflict between siblings in the same brood due to them having a lower r relative to each other than to themselves

Intrabrood conflict

behaviour of an optimally foraging individual in a heterogenous environment (curve of diminishing return)

Marginal value theorem (MVT)

incorrect measurements, mis-identification of factors, organism may not optimally forage (mal-adaptation, evolutionary lag, other factor)

Problems with optimization

Functional (adaptive), mechanical, phylogenetic (evolutionary history), ontogeny (development)

Tinbergen's 4 questions to investigate the behaviour of an organism

egg mimicry convergently evolved with host egg to reduce predation

Wallace hypothesis for egg mimicry

Game theory

a payoff matrix theory used to determine, which strategy or mixture of strategies will be evolutionarily stable, preventing another deviant strategy from doing better

where eggs are laid at different times, incubation begins at different time, results in some hatching sooner

asynchronous hatching

study of how the interaction between ecology, including the abiotic and biotic environment, and evolution, can result in specific animal behaviours

behavioural ecology

Epideictic behaviour

behavioural term coined by Wynne Edwards to refer to flocking behaviour that he suggested may be used in order for birds to census the population and adjust reproduction accordingly (due to physiological mechanism)

Village Weaver birds

bird species that were translocated by humans approx 200 years ago from a highly parasitised area in Africa, to the islands of Hispanola and Mauritius where parasitism was not found.

Collared flycatchers

bird used to calculate costs of reproduction. Found that mortality not affected, but when clutch size larger, birds laid fewer eggs the following year.

Extra-pair copulations (EPCs)

case in which sibling rivalry is further increased and would predict further aggression

males can be related or unrelated

composition of male take over groups of 2

males usually related

composition of male take over groups of 3-4

untreated, extra chick, extra egg, induced bird to lay extra egg

conditions used by Heany and Monaghan

states that a larger group will reduce the total number of attacks due to the prey confusing the predator and reducing focus on an individual

confusion effect

states that as group number goes up, despite total attacks increasing, individual risk of attack should decrease (1/n). Only if attacks don't increase by nx

dilution effect

irradiated one male so no eggs fertilized would hatch and then varied mating order with normal male, second male received 90% of paternity

double mating experiment

(p/y) small so adult mortality low and juvenile mortality high

equation conditions that would allow semelparity to evolve

N + (2P/y)

equation showing how many young a sexual semelparous animal needs to produce in order to equal the success of an iteroparous animal that produces N yound each year

lost egg signatures, low variation in whole population, low variation between individuals, reduced uniformity in clutch appearance (indicated not founder effect)

findings in egg appearance of village weaver birds that were moved

Brambling

highly discriminating host, who also has very recognisable egg signatures

Dunnock

host who is early in evolutionary arms race and has not got very strong defences

individual flexible assessment, genetic predisposition

hypotheses for how individuals determine which strategy to use in the ESS

dilution, confusion, synchrony in time, selfish herd, group defence, vigilance

hypotheses for the advantages of group living with respect to defence from predation

evolutionary lag, hidden cost to parents

hypotheses for why some animals don't produce an optimal clutch size even if they can successfully raise more when experimentally manipulated

Testing Darwin's and Wallace's hypotheses

introduced mimetic or non-mimetic eggs into reed warbler nest. Found equal predation rates, but 70% non-mimetic eggs rejected compared to only 3% mimetic eggs

infanticide a consequence of mammalian stable bisexual social system and not a cause

key finding about infanticide and social systems by Lukas and Huchard

reproductive skew

main problem with analysing average reproductive success

larger offspring produced, adults take longer to mature before reproducing, smaller brood

main results of Reznick's translocation experiment from area with high adult mortality to area with high juvenile mortality

multi-male and ovulation signals, multi-male and concealed ovulation, monogamy and concealed ovulation (prairie vole)

major transitions likely with evolution of concealed ovulation. Transitions may provide support for both hypotheses at different points

Nature pattern match

method used by Stoddard et al to compare egg signatures on host and mimic eggs and to determine, which features on an egg made the pattern a good signature.

Central place foraging model

model using MVT where birds will leave central nest or roost to forage at more distant locations

260

number of species compared by Lukas and Huchard

40min

optimal copulation time followed by most male yellow dungflies

Tangent to the curve

point on curve at which optimal values of both factors will be found. It is the greatest gradient

bisexual stable group, infanticide improves male success, female counterstrategy (paternal dilution), sperm competition, loss of infanticide

potential process of infanticide evolution and loss in mammalian species

Killifish (juvenile predator), Cichlid (adult predator)

predatory fish involved in Reznick's translocation experiment

female self-deception, monogamy associated with concealed ovulation

predictions if Alexander's and Noonan's hypothesis were true

multi-male group associated with concealed ovulation

predictions if Sarah Hrdy's hypothesis were true

species may not be independent samples as share a common ancestor, order that traits evolved unknown

problem with tabulating species traits simply

monitoring of nest, waits until ready to lay, removal of 1 host egg, rapid laying

process of cuckoo egg laying

siblicide, infanticide, suicide

progression of events that may occur in parent-offspring conflict, but later stages hardly ever reached

unfamiliar scent, pathological aggression, males have short tenure so killing young will make females receptive sooner

proximate and ultimate hypotheses for male lion infanticide

pheromones, cub suckling shared, male cubs of similar age to form fraternal take over groups

proximate and ultimate hypotheses for oestrus synchrony in female lions

isolated groups, whole groups die out

rare conditions that may result in group selection

when calculate gains (number chicks surviving) and losses (adult mortality) then maximum lifetime reproductive success lower than theoretical peak

reason why clutch size often lower than theoretical optimum

Alex Kacelnik

scientist examining starling central foraging to see if birds were optimising foraging time and load. Predicted that optimal load value would increase with increased distance from the feeding platform

Hogstedt

scientist who calculated optimal clutch size (not average) depending on experimental manipulation of magpie clutches. Initial clutch size was noted. Found that experimental optimum matched initial size.

Rebecca Kilner

scientist who determined that Linnet chicks with redder gapes would be fed more by parents. Honest indicator of hunger as blood is diverted away from digestive system.

Shizuka

scientist who examined American coot brood adjustment strategies. Found that after critical day 10 period, switched from a selective starvation strategy to a brood survival one. Coots favoured younger chick, which received more food. Older received more tousles. Optimal strategy may vary temporally.

Canestrari

scientist who found that Carrion crows can benefit from parasitism when predation risk greater, as cuckoo does not evict all eggs and will produce a repellent secretion. Fitness increase only found when predation cost outweighs parasite detection benefit

Sarah Hrdy

scientist who hypothesised that concealed ovulation has evolved in order to reduce infanticide, since males are not certain if they have mated with the female during oestrus

Geoff Parker

scientist who investigated the ESS for male yellow dungfly waiting times, determined that copulation time and egg fertilization followed a curve of diminishing returns and determined that males copulated for an optimal time. Also performed double mating experiment to show that 2nd male had paternity advantage.

David Reznick, 1990

scientist who manipulated the life history of guppies by moving fish between streams containing different predators

David Lack

scientist who not only proposed idea of optimal clutch size as increasing individual fitness, but also suggested selective starvation hypothesis. Often implemented in asynchronous broods where natural brood hierarchy in place.

David Lack

scientist who produced evidence against group theory by analysing the optimal clutch size of great tits. Found from experimental manipulation that experimental optimum generally matched observed. However observed was slightly lower.

Wynne Edwards

scientist who proposed the group selection theory mainly in terms of the population regulation hypothesis, where altruistic groups would outcompete selfish groups

Naomi Langmore

scientist who recorded the songs of the cuckoo parasite chick and the resident chick of the Fairy-Wren. Found that the parasite was able to mimic the song of the host very accurately in shape and frequency.

Mike Finnie

scientist who studied parental control of food allocation in yellow-billed hornbills. When parent in the nest, food allocation was equal and very few attacks on the smaller chick. When out of nest larger received more food and attacked the smaller.

Heithaus

scientist who studied the puzzling foraging behaviour of dugongs who appeared not to forage optimally. Found that when higher Tiger Shark predation, would use less productive edge zones compared to the more productive interiors.

Rob Magrath

scientist who tested selective starvation hypothesis in artifical 4 chick blackbird clutches. Asynchronous did better when food poor, but synchronous did slightly better when food plentiful, maybe due to reduce sibling rivalry

Tore Slagsvold

scientist who transplanted great tit chicks or blue tit chicks into the others' nest. Larger chick did better than smaller. For brood parasite to do well needs to lay in nest where chick larger than host, but egg has to be smaller

Trivers

scientist who used a model of parental investment against relatedness to show that there could be a zone of conflict between offspring and parent. Offspring optimal parental care is greater than parental optimum.

Hinde

scientist who used canaries to look at maternal effect of androgen deposition in eggs. Found parents controlled food provisioning by depositing different androgen levels and then responding to begging. Begging intensity influenced by hormones.

Craig Packer, 1991

scientist who used paternity testing on lions to access hypotheses on male take over groups

Stoddard

scientist who used tetrachromeric analysis to compare the host and parasitic egg. Found that background colour mimicry was better when host was more highly discriminatory.

Visser and Lessells

scientists who calculated the costs of reproduction to great tits in terms of adult mortality when experimentally manipulated clutch size. Found mortality increased as clutch increased.

Richard Alexander and Katharine Noonan

scientists who hypothesised that concealed ovulation has evolved as a means of encouraging mate guarding and paternal care. If female shows no signals, then males that remain with female may be more certain of paternity.

Ghalambor and Martin

scientists who investigated risk-taking in parental care in northern and southern hemispheric birds. Southern responded more strongly to risks to themselves whereas northern responded more to risk to offspring. Reflected in different clutch sizes and chances of adult survival.

Heany and Monaghan

scientists who manipulated nests of common terns who usually laid 2 eggs and then calculated average no. fledged

Lukas and Huchard, 2014

scientists who tested hypotheses for the evolution of infanticide in mammals using phylogenetic comparative studies.

Krebs and Davies

scientists who used a comparative study of Rallidae to look at the evolution of chick ornamentation. Appeared that ornamentation correlated with increased polygamy and clutch size so may have evolved as method of sibling rivalry. Supported by other study where more ornamented chicks fed more by parents

refinement of dilution effect, risk not evenly allocated, individuals associated with a larger domain of danger will have greater risk of attack. Animals should aim to reduce this by clustering closer together

selfish herd

low complexity (few features may reduce noise), large spacing, low interclutch variation

signature features of the highly discriminatory Brambling

Obligate siblicide (canism)

situation where one sibling always kills the other. Black headed vultures-maybe evolutionary lag as environment now not so productive. May be an insurance against other egg not hatching.

Cooperation

social behaviour found in lion take over groups, where males work together to increase their collective success. Group more likely to succeed in take over and have longer tenure.

humans, hanuman langurs, orangutans

species with concealed ovulation

bonobos, chimpanzees

species with conspicuous oestrus swelling

gorillas, gibbons

species with slight ovulation signals

clutch size variation, brood adjustment (selective starvation/brood survival)

strategies employed in optimising lifetime reproductive success when food supplies variable

all eggs hatch simultaneously

synchronous hatching

Comparative study

technique used in testing hypotheses where experimental manipulation is difficult or unethical. For example, when investigating the evolution of ovulation signals in primates.

Egg rejection threshold

theoretical calculation of strategy that should be deployed by a host when faced with a particular prevalence of parasite. Do not want to reject own egg, but do not want to miss a parasite, which would result in clutch loss anyway

Hawk-dove model

theoretical model of aggression (display and fighting) in a simplified population, where individuals only use one strategy

time spent travelling and collecting, load size

trade off when foraging

encouraging mate guarding and parental care in males, reducing risk of infanticide

two main hypotheses for evolution of concealed ovulation in primates

dishonesty physically impossible, high cost of signal shows true quality, signal shows true need

ways of maintaining an honest display when competing

Iteroparity

where animals reproduce repeatedly, surviving to the next season e.g elephants

Infanticide

where males kill the young of females in the group, usually after a male take over. An example of a spiteful social behaviour.

larger eggs than host are more likely to be rejected

why a small egg laid?

extra meal? improve incubation efficiency

why does cuckoo remove a host egg since they cannot count?

host will reject only one egg but will not generally reject only one chick

why not remove all the host eggs?

host much more alert to egg appearance if see a parasite

why such rapid laying?