Animal Behaviour Flashcards
what is behavioural genetics associated with?
the nature vs nurture debate
how do genes influence behaviour?
Regulatory genes are transcribed into RNA, which then controles other genes by turning them on or off. This is done by binding to “regulatory sites”, i.e., DNA regions on the chromosomes near structural genes.
Structural genes are transcribed into messenger RNA which in turn are translated into proteins.
Link also via “Structure” (e.g., certain behaviours can only be performed if the animal is big enough, has certain organs developed etc.)
find the powerpoint slide on this and write it up
what do family, twin and adopted studies say about the nature vs nurture debate?
Family Studies
Children share 50 percent of their genes with each parent. Therefore, for genes to be influential whatsoever, the trait in question must run in families. Obviously, a trait could be environmentally transmitted rather than inherited. For example, last names tend to run in families, but no one would claim that last names are genetic. Thus, running in families is a necessary, though not sufficient, condition for a trait to be genetic.
Twin Studies
Monozygotic (MZ, identical) twins share 100 percent of their genes, while dizogotic (DZ, fraternal) twins share only 50 percent of their genes (the same percentage as non-twin siblings). Therefore, to the extent that genes are influential, identical twins should be more alike than fraternal twins.
Adoption Studies
If shared environment is influential, then sibling reared in the same family should be more similar than adopted away siblings (siblings reared apart).
what is the most common study to conduct for environment vs genetics?
twin, adoption and family studies
what is the genetic basis of behaviour?
base triplets code for aminoacids
…which in a chain build enzymes and other proteins
…which build neurons, muscle cells, etc.
Even secondary structure of proteins is NOT encoded but depends on environmental factors (e.g. pH)!
Growth of (e.g.) neurons depends on sufficient supply of nutrients (
what is fitness?
Fitness can be understood as the number of offspring (surving to reproduce) that an organism with a particular genetic and phenotypic makeup can be expected to produce. Fitness is always compared with the performance of other members of he population or species, i.e., it is relative. It always depends on the environment.
why does not all behaviour have an adaptive explanation?
Not all traits are heritable
Other evolutionary forces (e.g., drift) may be at work
Selection pressures change over time (e.g., changing environment), they may be different for different sexes or age groups, etc.
Traits are not always independent of each other. → It cannot be assumed that every trait can be/is optimised undernatural selection.
There is no “goal”!
what was the Kasper-Hauser experiment and what form of genetic behaviour was is from
Genes and the Ontogeny of Behaviour: Nature-Nurture
An experiment in which an animal is reared in isolation from members of its own species (conspecifics) which birds were reared in isolation to determine which aspects of their songs are innate.
what are the advantages of learning?
animals might live in a variable or unpredictable environment, need to adapt to new situations to prevent themselves being wiped out. learning is faster than genetic determination meaning the current animal can adapt to its situation rather than descendants.
Spatial memory, e.g., food caching
Social learning for dietary selection and preferences
Better predator responses (e.g., knowing where to hide)
Hunting strategies depending on prey availability
what is neuroplasticity?
Neuroplasticity: refers to the brain’s ability to CHANGE throughout life. The human brain has the amazing ability to reorganize itself by forming new connections between brain cells (neurons).
This means that when people repeatedly practice an activity or access a memory, their neural networks – groups of neurons that fire together, creating electrochemical pathways – shape themselves according to that activity or memory. When people stop practicing new things, the brain will eventually eliminate, or “prune,” the connecting cells that formed the pathways.
In addition to genetic factors, the environment in which a person lives, as well as the actions of that person, play a significant role in plasticity.
Neuroplasticity occurs in the brain:
1- At the beginning of life: when the immature brain organizes itself.
2- In case of brain injury: to compensate for lost functions or maximize remaining functions.
3- Through adulthood: whenever something new is learned and memorized
The brain’s ability to reorganize itself by forming new neural connections throughout life. Neuroplasticity allows the neurons (nerve cells) in the brain to compensate for injury and disease and to adjust their activities in response to new situations or to changes in their environment.
when is it useful to learn?
neuroplasticity because Cell death is irreversible→ Strong stimuli are more effective when many connections are “still under development”
usually especially in early periods
(sometimes) sensitive period(s) such as imprinting
what is Filial imprinting?
The best-known form of imprinting is filial imprinting, in which a young animal acquires several of its behavioral characteristics from its parent. It is most obvious in nidifugous birds, which imprint on their parents and then follow them around
this also works for parents not just newborns for example American coot mothers have the ability to recognize their chicks by imprinting on cues from the first chick that hatches. This allows mothers to distinguish their chicks from parasitic chicks.
what was the experiment by cooper and zubeck 1958
They raised genetically maze-bright and maze-dull rats in different environments: normal, enriched, and impoverished. They found a difference in maze performance only in the normal condition. In the enriched and impoverished conditions, the performance difference was not significant.
what did Tinbergen find with his experiment on herring gulls?
Herring gull chicks pecked at their parents’ red-tipped bills to get food. Crude models showed the releasing stimulus to be the color red on the bill, and pecking intensity correlated with greater contrast between the bill and the red tip
what was Tinbergens experiment with Stickleback fish in relation to releasing stimuli
Male stickleback fish attack each other in the spring when their bellies become red. To test that the belly color was the releasing stimulus, Tinbergen made realistic stickleback models with no red bellies and crude models with red bellies. Supporting his hypothesis, the fish attacked the red-bellied models.
define sexual imprinting
Sexual imprinting is the process by which a young animal learns the characteristics of a desirable mate. For example, male zebra finches appear to prefer mates with the appearance of the female bird that rears them, rather than that of the birth parent when they are different.
e.g.
what is kin selection?
Kin selection is the evolutionary strategy that favours the reproductive success of an organism’s relatives, even at a cost to the organism’s own survival and reproduction
what is hamiltons rule? (kin selection)
According to Hamilton’s rule, kin selection causes genes to increase in frequency when the genetic relatedness of a recipient to an actor multiplied by the benefit to the recipient is greater than the reproductive cost to the actor. The rule is difficult to test but a study of red squirrels in 2010[3] found that adoption of orphans by surrogate mothers in the wild occurred only when the conditions of Hamilton’s rule were met. Hamilton proposed two mechanisms for kin selection: kin recognition, where individuals are able to identify their relatives, and viscous populations, where dispersal is rare enough for populations to be closely related. The viscous population mechanism makes kin selection and social cooperation possible in the absence of kin recognition. Nurture kinship, the treatment of individuals as kin when they live together, is sufficient for kin selection, given reasonable assumptions about dispersal rates. Kin selection is not the same thing as group selection, where natural selection acts on the group as a whole.
advantages of mixed species groups?
lookouts - using each others special skills to look out for predators e.g. bird calls and meerkats, bird sometimes fake calls to get the food the meerkats are eating
The “many eyes” effect shows that the more group members there are, the more alert the group can be and the higher the likelihood that a predator will be spotted in time.
dilution effect: the more conspecifics there are the less chance of predation for a particular individual
The confusion effect decreases the possibility of being caught, as the more group members there are, the more confused the predator will be as to which individual to attach, when they all disperse.
efficient foraging
Information pooling is often seen in homing pigeons as they are more likely to find their way home if they are in a group. Helping can be advantageous as individuals get help for raising their offspring, increasing the chances of survival for the young in the group,
disadvantages of mixed species living?
larger group size - more conspicious to predators, . In a mixed species group, one species could be more conspicuous than another
food competition increases and food resources might be depleted more rapidly. This would be less of a problem in mixed-species groups if the different species forage on different foods, which is commonly the case.
parasite and disease spread
mutualistic relationships become parasitic e.g. birds feeding on buffalos flees and ticks may start to open scabbed wounds to feed on the blood.
describe the steps performed in a paternity analysis using satelitte markers
A microsatellite is a tract of repetitive DNA in which certain DNA motifs are repeated, typically 5–50 times CACACACA
They are widely used for DNA profiling in kinship analysis, genetic linkage in paternity tests and in forensic identification.
what is the challenge hypothesis?
CAPTIVE males of temperate-zone birds: long days → gonadal development & increase in T → normal spermatogenesis, secondary sex characters, & repertoire of reproductive behaviour (sexual & aggressive)
NATURE: Absolute level of T can be an order of magnitude higher in the wild
T increases only some forms of aggression, i.e. reproduction related (not, e.g., anti-predator)
MOST IMPORTANTLY: In the wild, T is higher because males face CHALLENGES from competitors, and other challenging situations
Temporal pattern of T secretion above the breeding baseline may be a trade-off between male-male aggression and parental behaviour
what is communication?
using specially adapted structures and behaviours to modify the actions of receivers, these adaptions are called signals
what is the difference between a cue and a signal in communication?
signal: adaptations of behaviours and structures to modify actions
cue: rustling in the grass of a mouse which an owl spots. Rustling elicits behaviour in the owl, but has not been shaped by selection for that purpose
give examples of 3 types of signals
chemical: pheromones (ant trails)
auditory: primate territorial or alarm calls, bird song
visual: bioluminescence, sexual displays
what makes a good signal?
Easy for receivers to pick up Detectable Recognizable Easy for signallers to produce Efficient Low-cost Hard for eavesdroppers to detect
balance of all above
Conspicuous (distinguishable) From background From other species From other calls that you make Stereotyped Less is more Alerting components
Ritualization
The process of evolving towards these characteristics
what is darwins Principle of antithesis
Darwin proposed that some actions or habits are carried out merely because they are opposite in nature to a serviceable habit, but are not serviceable themselves. Shrugging of the shoulders is an example Darwin used of antithesis, because it has no service. Shoulder shrugging is a passive expression, and very opposite of a confident or aggressive expression
describe ritualisation in communication
Ritualized behaviors allow for the evolution of a signal by increasing conspicuousness, stereotypy, and separation from its original function. An example of such increasing exaggeration can be found in bower birds. Males decorate their nest with blue objects. They will steal any blue object, including pieces of paper, plastic, and glass. This behavior began as nest building and has evolved to attract females.
The process of ritualization first involves the receiver noticing the correlation between the signal and the actions of the sender. The sender then ritualizes his signal to receive the optimal ideal response from the receiver and the receiver modifies his response to optimally benefit himself. As an example, a dog who is preparing to bite retracts his lips into the familiar growl snarl. This particular behavior began so that the dog does not bite his own lips as he bites. However at some point in evolutionary history, the receiver noticed that the snarling dog presented a danger to him. The signaling dog now notices the receiver often backs down before the fight even begins, and continues retracting his lips as a way to ward off the receiver.
what are the aims of bird song? how is it used in communication?
maintain territories and attract females
what is the environmental effect on bird song?
tropical environment: pure tone, short whistles
uk: long complex trills
this is due to attenuation (lost in background noise) and Degradation: confused with other sounds / species
as there is more varied habitat in the uk birds must adapt their calls to their surroundings, in Forest: Echoes off objects - this is worse for higher frequencies and echoes are confused with notes. in grassland calls are lost by gusts of wind and wind masks long notes
forest habitats are larger than grassland
what did morton 1975 show?
he showed that bird call correlated with habitat structure, where grassland birds called at higher frequencies and had a larger frequency range but exhibited less pure tones than forest birds
what did Mockford EJ 2011 show?
spectral properties of bird song differ between urban and rural environments. they showed that the physical structure of urban areas may have a contributory effect. Here we investigate the sound degradation properties of woodland and city environments using both urban and rural great tit song. We show that although urban surroundings caused significantly less degradation to both songs, the transmission efficiency of rural song compared to urban song was significantly lower in the city.
We suggest that the structure of the acoustic environment, in addition to the background noise, plays an important role in signal adaptation.
what is honest signalling?
Zahavi’s handicap principle states that in order to be honest, a signal must be costly to the signaler. Thus, only the most fit individuals can afford to brandish an honest signal. For females looking for a mate, such a declaration of fitness will identify a particular male as a quality choice. For this reason, some signals, such as peacock’s tails, become extremely exaggerated: males are trying to declare their fitness. Only the toughest males can survive with such a costly, conspicuous tail. Another example is the black bib of dominant male Harris sparrows. Only dominant males have this black bib. An experiment in which males were given a black bib by means of a magic marker showed that male was attacked by other sparrows. The male with an artificial black bib could not survive the attack; only the fittest males could have the black bib of dominance and not lose fights by challengers. There is currently much debate over whether the handicap principle is valid, and there is some evidence that it does not always hold true. However, in general, a costly signal such as a peacock tail that can serve no other purpose are honest indicators of fitness.
what two forms of mimicry has honest signalling given rise to?
batesian and Mullerian mimicry
batesian
a dangerous signaler is imitated by a harmless mimic, a
mullerian
dangerous species evolve mutual imitation to the benefit of both.
Mullerian mimicry often occurs when two similar species, both of which are dangerous, have some overlapping habitat. By resembling each other, a predator that learns to avoid one will be more likely to avoid the other. In this case, the predator saves itself a hard lesson learned twice, and the mimics avoid a sacrificial encounter.
what did feymen and jackson suggest? and how do ants use pheromones
Recruiment: bring nestmates to point in space where work is required
ants sweep antennae side to side and follow the strongest side of the pheromone trail (left hand side or right hand side)
he suggested there were two trails of pheromones left by ants, in an xoxoxo pattern but that doesnt provide infomation about direction to and from the ant nest.
so he suggested they left patterns like x0 x0 x0 to go one way and ox ox ox to go the other way but lots of trails left by lines of ants again contradicted this as it was hard to read them all overlapping.
Jackson found that pheromone trails split off at 60 degree angles away from the existing trail so it find its way back it just needs to find a junction to rejoin the main pheromone path
how do honey bees use pheromones?
Alarm: causes attacking behaviour, Social insects warn nestmates of enemies, Release chemical when sting to recruit nestmates to sting
Brood recognition: identifies brood caste
Drone: causes drone aggregation
Dufour’s gland: labels queen’s eggs
Footprint: enables following
Queen mandibular: inhibits ovary development in workers
Queen retinue: attracts workers to queen
what is scent marking used for in mammals?
In mammals, scent is often used to mark territorial boundaries, in aggressive interactions between males (reviewed in Gosling & Roberts 2001) or to advertise oestrus in females.
Relatively long-lasting- so communication can continue in the absence of the signaller
Territorial males and dominant males usually mark more than non-resource holders (eg. in house mice, Mus musculus Hurst 1990).
Thornhauster et al. (2013) found that female house mice preferred to mate with males that had scent marked more frequently.
what is the scent matching hypothesis?
Gosling (1982) “scent matching hypothesis”: Receiver could compare smell of scent marks in an area with that of rival males it encounters
If scents match, allows the receiver to assess dominance and ownership status of the rival and back down if appropriate.
Resource holder would benefit by fewer fights with rivals.
e.g. Territorial male hartebeest, Alcelaphus buselaphus, allow intruders to sniff them (and therefore to match their scent with that in the territory) (Gosling 1982).
what is the difference between dispersal and migration
dispersal is one way movement
migration is two way movement (herds will often travel back to the original site) Migration is an innate response of an animal population to periodic changes in environmental conditions
what is philopatry?
Behaviour of remaining in, or returning to, an individual’s birthplace.
what is natal philopatry
Natal philopatry commonly refers to the return to the area the animal was born in, or to animals remaining in their natal territory. It is a form of breeding-site philopatry
are both genders philopatric?
In species that exhibit lifelong monogamous pair bonds, even outside of the breeding season, there is no bias in the sex that is philopatric.[8] However, among polygynous species that disperse (including those that find only a single mate per breeding season), there is a much higher rate of breeding-site philopatry in males than females among birds, and the opposite bias among mammals
Among birds, males invest highly in protecting resources – a territory – against other males. Over consecutive seasons, a male that returns to the same territory has higher fitness than one that is not philopatric.[9] Females are free to disperse, and assess males
why do individuals disperse?
locating new resources, escaping unfavorable conditions, avoiding competing with siblings, and avoiding breeding with closely related individuals which could lead to inbreeding depression.
what are the negatives of dispersing?
energy, risk, time and opportunity.[2] Energetic costs include the extra energy required to move as well as energetic investment in movement machinery (e.g. wings). Risks include increased injury and mortality during dispersal and the possibility of settling in an unfavorable environment. Time spent dispersing is time that often cannot be spent on other activities such as growth and reproduction. Finally dispersal can also lead to outbreeding depression if an individual is better adapted to its natal environment than the one it ends up in. In social animals (such as many birds and mammals) a dispersing individual must find and join a new group, which can lead to loss of social rank
what is the optimal-inbreeding hypothesis and why is it related to philopatry?
it is one of two hypothesis on evolution of natal philopatry
Shields (1982) suggested that philopatry was a way of ensuring inbreeding, in a hypothesis known as the optimal-inbreeding hypothesis.[12] He argued that, since philopatry leads to the concentration of related individuals in their birth areas, and thus reduced genetic diversity, there must be some advantage to inbreeding – otherwise the process would have been evolutionary detrimental and would not be so prevalent. The major beneficial outcome under this hypothesis is the protection of a local gene complex that is finely adapted to the local environment.
do all ages disperse equally?
Some organisms are motile throughout their lives, but others are adapted to move or be moved at precise, limited phases of their life cycles. This is commonly called the dispersive phase of the life cycle
most animals either disperse when born (natal dispersion) or when breeding as adults (breeding dispersion)
In general there are two basic types of dispersal:
Density-independent dispersal
Organisms have evolved adaptations for dispersal that take advantage of various forms of kinetic energy occurring naturally in the environment. This is referred to as density independent or passive dispersal and operates on many groups of organisms (some invertebrates, fish, insects and sessile organisms such as plants) that depend on animal vectors, wind, gravity or current for dispersal.[9][10]
Density-dependent dispersal
Density dependent or active dispersal for many animals largely depends on factors such as local population size, resource competition, habitat quality, and habitat size.[11][12][13]
Due to population density, dispersal may relieve pressure for resources in an ecosystem, and competition for these resources may be a selection factor for dispersal mechanisms.[14]
Dispersal of organisms is a critical process for understanding both geographic isolation in evolution through gene flow and the broad patterns of current geographic distributions (biogeography).
analysis steps in using microsatellite markers for paternity analysis
match ANALYSIS
steps: Select 1-2 strongest bands Ignore lighter bands beneath alleles (“shadow bands”) The lower allele is usually stronger If highest is strongest = homozygous
how do microsatellites help to understand the social systems of a species?
Can provide information on the species’ mating system!
e.g. Tamarins: females mate with several males, but one male tends to monopolise paternity. without a parentage analysis scientists would have no idea which males are successfully mating with females if any.
relatedness is based on how many alleles are shared,
& how frequent these alleles are in population
a RELATEDNESS-COEFFICIENT can be calculated for dyads and leads to kin selection.
Kin selection is the evolutionary strategy that favours the reproductive success of an organism’s relatives, even at a cost to the organism’s own survival and reproduction
what is eruptive dispersal and why does it occur?
Eruptive dispersal: ‘Episodic dispersal in large numbers’.
could be due to:
bad weather conditions
boom and bust in food supplies
eruptive species:
waxwing birds
crossbill birds
what two types of migration are common in birds
Daily migration:
For example, to and from a roosting area. e.g. waders at high tide
Seasonal migration:
Passage at one season from a place of hatching and a return at another season to the same general area. e.g. summer migrants (warblers) or winter migrants (Whooper swans)
Some species do both
what is an energy saving strategy of migration?
slip streaming in birds, the term “slipstreaming” describes an object traveling inside the slipstream of another object (most often objects moving through the air though not necessarily flying). If an object is inside the slipstream behind another object, moving at the same speed, the rear object will require less power to maintain its speed than if it were moving independently. In addition, the leading object will be able to move faster than it could independently, because the rear object reduces the effect of the low-pressure region on the leading object.
hitch hiking:tired migrating birds often alight on ships
why study migration?
Pure research:
For example, avian energetics.
Implications for wildlife conservation.
Applied research:
Track spread of disease:
For example, Avian flu.
Aeroplane safety:
For example, bird strikes where bird hit the plane accidentally due to the plane flying across bird migration routes
what is kin altruism
Kin altruism is altruistic behaviour whose evolution is driven by kin selection
give an example of kin selection
sterile social insects, such as honey bees, which leave reproduction to their sisters, arguing that a selection benefit to related organisms (the same “stock”) would allow the evolution of a trait that confers the benefit but destroys an individual at the same time
what is hamiltons rule?
According to Hamilton’s rule, kin selection causes genes to increase in frequency when the genetic relatedness of a recipient to an actor multiplied by the benefit to the recipient is greater than the reproductive cost to the actor. The rule is difficult to test but a study of red squirrels in 2010[3] found that adoption of orphans by surrogate mothers in the wild occurred only when the conditions of Hamilton’s rule were met. Hamilton proposed two mechanisms for kin selection: kin recognition, where individuals are able to identify their relatives, and viscous populations, where dispersal is rare enough for populations to be closely related. The viscous population mechanism makes kin selection and social cooperation possible in the absence of kin recognition. Nurture kinship, the treatment of individuals as kin when they live together, is sufficient for kin selection, given reasonable assumptions about dispersal rates. Kin selection is not the same thing as group selection, where natural selection acts on the group as a whole.
why is it useful to learn?
variable/unpredictable environment→ more flexible than genetic determination
faster
…but depends on usefulness of past experience
e.g.,
Spatial memory, e.g., food caching
Social learning for dietary selection and preferences
Better predator responses (e.g., knowing where to hide)
Hunting strategies depending on prey availability
when is it useful to learn?
usually especially in early periods
(sometimes) sensitive period(s)
Remember: Neuroplasticity! → Cell death is irreversible→ Strong stimuli are more effective when many connections are “still under development”
But many species have life-long capabilities to some extent
what is neuroplasticity
Neuroplasticity is the brain’s capacity to change and adapt.
physiological changes in the brain that happen as the result of our interactions with our environment.
From the time the brain begins to develop in utero until the day we die, the connections among the cells in our brains reorganize in response to our changing needs. This dynamic process allows us to learn from and adapt to different experiences.
what is important to learn?
Learning pre-dispositions
Learning capabilities of species depend onphylogeny (increasing centralisation of neural systems;e.g., insects, cephalopods, vertebrates)
many species have special capacity for certain tasks, that are relevant for their niche:e.g.
what is learning?
Animals gain knowledge in two ways . First is learning—in which an animal gathers information about its environment and uses this information. For example, if an animal eats something that hurts its stomach, it learns not to eat that again. The second is innate knowledge that is genetically inherited. An example of this is when a horse is born and can immediately walk. The horse has not learned this behavior; it simply knows how to do it.[44] In some scenarios, innate knowledge is more beneficial than learned knowledge. However, in other scenarios the opposite is true - animals must learn certain behaviors when it is disadvantageous to have a specific innate behavior. In these situations, learning evolves in the species.
