animal behaviour final

define proximate explanations in behaviour

these focus on mechanisms of behaviour (genetic, neural, developmental, hormonal) e.g., pheromones from dominant female influences timing of oestrus cycles of other females

define ultimate explanations in behaviour

these focus on adaptation and evolutionary processes of behaviour e.g., cubs born synchronously survive better as they are able to nurse communally

name the three methods for studying behaviour

• comparison within a species

• experimental tests

• comparative studies

what is migration?

migration is the persistent and directed movement effected by the animal's own locomotory exertions. it is typically a round-trip event, regular and predictable movements between breeding and non-breeding areas

what are some ways that animals navigate?

• navigation by piloting (learning features and landmarks in an environment)

• navigation by path integration (keeping track of all turns and speed throughout a trip)

• navigation by odour (e.g., salmon learn the odour of their stream and use this to home as adults)

• navigation by celestial compass

• navigation by sun compass

• navigation by magnetic fields

how do animals find their way?

1. navigation

2. distance to destination, governed by restlessness

3. genetic basis

costs of migration

• high energy cost

• predation risk

• exposure to new diseases and parasites

migration should only occur when benefit > cost

benefits of migration

• avoid food shortage

• exploit temporarily favourable conditions

• escape disease

define dispersal

movement of species from one place to other away from their place of origin

costs of dispersal

• higher risk or predation or mortality

• unfamiliarity with new location could lead to less feeding or mating

benefits of dispersal

• inbreeding avoidance hypothesis (where risk of breeding with a relative decreases)

• intraspecific competition hypothesis (dispersal can reduce competition for mates and resources with close relatives)

what is the "ideal free distribution hypothesis"?

a model that predicts the spread of competitors across different habitats that vary. animals should first settle in good habitats, because at low densities, individuals do best. as the best habitat becomes increasingly populated, fitness declines to a point where individuals would have more success in moderate or poor habitats that are less populated.

• the model assumes animals have perfect knowledge of the distribution of resources

• assumes that animals are passive and free to move between habitats and go to the best possible site

what is a monogamous mating system?

a mating system where there is 1 male and 1 female with equal parental investment. this results in little sexual dimorphism in size and strength e.g., blackbird, NZ robin, and some primates

what is a polygynous mating system?

mating systems where 1 male mates with several females. mating can be simultaneous or sequential. in this case, female > male parental care, common in most mammals and red-winged blackbird

what are polyandrous mating systems?

a mating system with 1 female and several males. mating can be simultaneous or sequential. male > female parental care e.g., honey bees: where the queen mates with a dozen males

what are polygynandrous mating systems?

where females and males each pair with several members of the opposite sex.

how do different social mating systems arise?

conflict between males and females reproductive success, as polygyny maximises males' reproductive success, whereas polyandry maximises females' reproductive success. therefore, the best strategy for a male is not the best strategy for a female and vice versa

what may constrain social mating systems?

resource distribution may be a constraint:

• for females, reproductive success is usually limited by resources; as eggs are more costly than sperm to produce

• male reproductive success is usually limited by access to females

mating systems might be a product of resource (and thus) female distribution

what is the male assistance hypothesis?

in some species, male care is a resource for females, therefore the need for male care could influence evolution of mating systems and enforce monogamy on males

a benefit of dispersal includes the inbreeding avoidance hypothesis. what is this?

inbreeding can be the cause of major genetic consequences in populations through inbreeding depression. chances of this occurring can be reduced by dispersal, as it reduces the chance of individuals mating with close relatives and inbreeding depression

another benefit of dispersal is the intraspecific competition hypothesis. explain this hypothesis.

competition between individuals of the same species over resources like food, water, space and access to mates is a key driver of population dynamics and evolution. dispersing reduces competition, increasing survival and reproduction for both sedentary individuals and dispersing individuals

what are the different types of polygyny? explain how they work

1) harem-defence polygyny - occurs when a male directly defends several females

2) resource-defence polygyny - occurs when males defend resources that females require

3) scramble-competition polygyny - male does not defend territory, but roams in a "frenzy" in search of multiple females

4) lek polygyny - male attracts multiple females to display area for mating (small territory without resources for females)

why do some secondary females accept polygyny?

1. a female may be deceived into accepting polygyny: after pairing with first mate a male might defend a second territory and attract a second female who is unaware. after mating with the second he will abandon her and return to the first.

2. polygyny can be in a female's best interest

describe the polygyny threshold model

territory quality differs among males, and female success increases with territory quality. therefore, females should choose to mate with males in higher quality territories, even if it means she mates polygynously and is the secondary female. this way, reproductive success is higher than being the primary female in a low quality territory

why don't lek males defend a large territory?

1) females are too unpredictable and too widely distributed

2) population density is too high to make defence of territory economic

what are the 3 hypotheses for lek polygyny?

1. hotspot hypothesis - where males gather in places where females are predicted to travel

2. hotshot hypothesis - subordinate males gather around 'hotshot' male so they can obtain matings with females wanting to mate with the hotshot

3. female preference hypothesis - females prefer males in groups (reducing the cost of mate choice for females)

what is the difference between simultaneous and sequential polyandry?

simultaneous is where a female lays a clutch or litter which is fertilised by several males. sequential polyandry is where a female has a series of distinct mating events, laying a clutch or litter for each male

why might males accept polyandry?

1) shortage of females

2) may be their only chance of reproductive success as they gain nothing by deserting the female

why do females usually invest more in parental care than males?

1. females are more sure of maternity than males are of paternity

2. lost future mating opportunities are greater for males than females, as millions of sperm are produced of which most are lost

review the 3 hypotheses that have been proposed to explain the apparent link between mode of fertilisation and whether parental care is by males or by females.

1. paternity certainty hypothesis - a male's level of paternal care is directly related to how certain he is that the offspring are his. males are more certain when fertilisation is external as he is present at time of fertilisation, in comparison to internal he is less sure

2. gamete order hypothesis - parental care is determined by order of gametes. internal fertilisation favours maternal care as males are given an opportunity to abandon females after fertilisation. external favours paternal as males must wait until eggs are laid to fertilise, giving females an opportunity to abandon

3. association hypothesis - parental care is determined by prior association with the embryo: internal fertilisation favours maternal care as females have association with the embryo. external fertilisation favours paternal care as eggs are laid in male territory, thus have close association with males

what is intrabrood and interbrood conflict?

intrabrood conflict is competition between siblings within the same brood for parental investment. interbrood conflict occurs between parents and offspring, where offspring demand more investment than the parents are willing to give, as they may be withholding for future broods

name some behavioural adaptations to avoid diseases and parasites.

• disgust

• avoid disease filled habitats

• avoid sick or infected individuals

• living in lower density

how does disease trade-off against predation risk?

solitary animals are more prone to predation risk, which reduces as sociality of the species increases. on the other hand, disease risk is highest in colonial animals, gradually reducing as sociality decreases, with solitary animals at least risk of disease

name costs and benefits to living in groups.

costs:

• pathogen transmission

• cuckholdry

• conspecific competition for food, mates

• cannibalism

• infanticide

benefits:

• predator detection

• aggregated resources

• reduced cost of finding a mate

• food and social information

what are benefits of living in a group when it comes to predation?

• many eyes hypothesis, the time an individual must be vigilant decreases, predator may be spotted quicker

• harder to target groups than individuals

• predator confusion

• communal defence, prey in groups can defend themselves

what is the selfish herd hypothesis?

this theory explains how individuals within a large group will always try to place themselves in the centre of the herd where it is safest. every animal acts in its own self interest (selfish), hence the constant movement within herds to stay in the safest place

what is the prisoner's dilemma in the context of cooperation and altruism in animals?

in the prisoner's dilemma, each individual can choose to either cooperate for mutual benefit or betray the other for individual gain. in animal cooperation, the solution is "tit-for-tat", where one should cooperate on the first move, then copy what the other does. the result is an evolutionary stable strategy, in which repeated interactions can lead to reciprocal cooperation

when does conditional reciprocity occur?

• when individuals associate regularly

• past exchanges predict future exchanges

• roles reverse

• recipient benefits > donor costs

• when cheaters can be recognised and punished

what is the difference between plural and singular breeders?

in plural breeders, multiple females breed and simultaneously share care. in singular breeders a single pair breeds (gains all advantages). there are two types of singular breeders: facultative, in which the pair can breed with or without assistance from helpers, and obligate, where the pair is unable to breed successfully without helpers

why do some animals share raising of offspring?

may be due to kin selection and increasing the success of shared genes, boosting social status or prestige, future reproductive success

why do helpers stay and not breed themselves?

helpers may be faced by ecological constraint, making it more beneficial to stay and help relatives or be waiting for reproductive opportunities. ecological and life history constraints may prevent them from breeding or they may be controlled by dominants

what are some consequences of cooperative breeding?

longevity of dominant females is significantly less than males and helpers due to the cost of reproduction. population dynamics can be created leading to the Allee effect, as small populations may not be able to maintain themselves due to lack of helpers

what is the difference between intrasexual and intersexual selection?

intrasexual selection is selection between members of the same sex for access to mates, while intersexual selection is selection where members of one sex choose mates depending on certain traits

describe sexual conflict that arises from male and female best interests.

a male's best interest in fertilisation efficiency is to fertilise all eggs, while a female's is to have control over which male fertilises, to ensure favoured genes. offspring production differs where males want to produce as many as possible due to the little cost on them, while females consider future reproduction and their own survival as initial investment is significant

explain fisher's runaway model.

this model explains how exaggerated male traits can become due to female preference. traits may become so extreme that it results in a survival cost for males, but females continue to prefer these extreme traits over less extreme

how does the handicap principle relate to the runaway model?

the runaway model results in male traits becoming extreme, leading to a survival disadvantage. the handicap principle suggests females deliberately choose males with a costly trait, as it becomes as honest indicators of an individual's fitness, assuming that only the best males can survive with the handicap

what are the 3 types of sender receiver interests?

• opposing - both parties have diverging interests like predator/prey

• separate but not opposing - diverging interests but not opposing; for their own benefit

• overlapping - common interests between sender and receiver like alarm calls

what is referencial signalling?

forms of communication within a species where a signal is associated with a specific event or object. for example, vervet monkeys have distinct calls to alert when there is a snake, leopard, or eagle, to which they all respond accordingly to avoid the predator

what is aggressive mimicry?

a predatory tactic where a predator mimics a harmless species or object to deceive and lure prey

define primary defences and name a few examples.

primary defences occur regardless of whether there is a predator in the vicinity. the predator may not recognise prey at all through hiding, masquerade or crypsis. or they may detect prey but fail to recognise it as edible through masquerade, aposematism, or batesian mimicry

what is perceptual exploitation?

the exploitation of a receiver's pre-existing bias in sensory and cognitive system to manipulate its behaviour for the sender's gain

what is aposematism?

aposematism is the defence mechanism where prey species use bright colours and distinct patterns to warn predators that they are dangerous

explain the difference between batesian and mullerian mimicry.

batesian mimicry is when a harmless species evolves to mimic a dangerous model species. this way, they can avoid predation due to the predator's knowledge of distasteful prey. mullerian mimicry is where similar dangerous species evolve to resemble each other, with similar warning colours and patterns, with shared traits reducing mortality for each species

what are chemoreceptors and mechanoreceptors?

chemoreceptors detect chemical stimuli, allowing animals. to find and identify food, locate habitats and mates, detect and avoid predators.

mechanoreceptors sense physical deformation caused by stimuli such as pressure, stretch, motion and sound.

what are the two types of photoreceptors in vertebrate eyes?

rods - sensitive to light but do not distinguish colours

cones - distinguish colours but are not as sensitive; colours are perceived by comparing excitation of the three different kinds of cones

what are the two modes of action for hormones?

activational effects - short term, reversible effects that occur in a fully developed organism (territorial behaviour in birds)

organisational effects - long term, irreversible effects on development that can directly or indirectly influence behaviour (puberty)

what is the relationship between corticosterone and memory?

corticosterone is the equivalent to cortisol, a stress hormone. it takes time to accumulate in the body after a stressful event and inhibits memory

what are the two major classes of hormones?

peptides - small chain amino acids that can initiate a cascade of metabolic processes in the cytoplasm. usually leads to short term effects like the production of more or less hormones.

steroids - larger molecules, longer chains derived from cholesterol. may affect gene expression in the nucleus, producing long term effects

what is the auditory template hypothesis?

this hypothesis proposes that young songbirds possess innate templates of their species song through a genetic component. to fully learn their song, they requiring environmental influences like hearing an adult sing the song. additionally, they require auditory feedback to ensure they are singing the correct song

what is overproduction and selective attrition?

juvenile songbird learning involves two phases. overproduction is the phase where they try out many songs, while selective attrition is when selected songs become crystallised while others are discarded

describe the two pathways in the bird brain during song learning.

motor pathway - for producing song

anterior forebrain pathway - learning and plasticity

what is the HVC and why is it important?

the HVC is sometimes referred to as the song control centre, as it generates the precise timing and syllables in a bird's song. damage to the HVC can alter the ability of a bird to sing its song correctly

how does learning in songbirds relate to human speech?

both humans and songbirds rely on a sensorimotor control of a vocal system and depend critically on auditory feedback from themselves and others for normal learning.

why should behavioural researchers be concerned with conservation?

1) there is an accelerating and world-wide decline of species

2) if those with knowledge do not address this problem then it will be made by those less informed, leading to more damage

3) recognition that animals are not being studied in a pristine environment

what is conservation biology?

the study of how populations and their habitats respond to anthropogenic change, and use this knowledge for protection and restoration of biodiversity as well as political leverage to achieve these goals

what is the sex allocation theory and its relation to over-fed kakapo?

the sex allocation theory favours a 1:1 sex ratio among offspring in most species, but deviations occur due to differences in maternal conditions and parental care. a female should produce more sons when in good condition and females when in poor condition (less expensive). in kakapo, males weight significantly more than females, so females only produce sons when they can afford the extra cost. ignorance of sex allocation theory led doc to create a male biased population by over feeding females.

personal actions to preserve animal behaviour

• reduce your environmental footprint

• help restore habitats and environments for native species

• support conservation organisations

• become a researcher

• take time to enjoy nature