Week 6-end Flashcards
What is sexual selection and what are the mechanisms
A form of natural selection acting on traits to compete for mates, even if they’re costly as long as they get to do the deed
Mechanisms
1. intrasexual selection (same sex competition to get a mate)
2. Intersexual selection (sexual interactions affecting mate choice)
What is the reproductive skew, the asymmetry in the selection, and anisogamy
reproductive skew:
- Unequal partitioning of reproductive success with population (leads to reproductive variance)
- Sexual selection favors traits for one sex = associated reproductive behaviors
asymmetry in sexual selection
- Girls make 1 big egg, guys make a lot of mini sperm(cheap to produce)
anisogamy
- Fusion of two gametes to differ greatly in size
What is the bateman gradient and principle
Gradient:
- Male’s reproductive success increases w/his number of mates (positive correlation)
Females must secure resource to create then raise offspring so her’s is dependent on quality not quantity of mates
Principle:
- Because males achieve greater reproductive success, they tend to have more mates than females = they have higher reproductive variance
What is the sex different perspectives on parental investment
- Costly parental activities that increase survival of offspring decreases their likelihood of producing more offspring
- Females are likelier to gain benefits from raising kids
What is the operational sex ratio
- both genders have the same reproductive success average BUT differ in variance (Females don’t gain much from mating AGAIN, so usually less sexually active than males
** ratio of sexually active males to sexually receptive females - Key differences evolve from type of gametes produced amplified with variation in degree of parental care
What is the theory of sex differences and role reversal
Postulates as a result of 1-3 operates more strongly in the sex where competition for mates is greatest
1. sex differences in mating behaviour
- Reproductive variance and skewed operational sex ratio
- Sexual selection
sex role reversal
- Change in typical behaviour patterns between the sexes
- In species where males contribute more parental investment, we can predict competition for mates and mate choices by males
What do we know about pregnant males
- Some offer brood pouches for females to place eggs (seahorse) and free ones actively choose among mates
- Pregnant pipefish guys provide nutrients to clutch of eggs for weeks
- Females compete for opportunity to donate their eggs
- Experiment showed guys would rather feed then mate
- Offspring survival is partly influenced by female body size (motto motto likes em big) and striping patterns
- Female competition exerts strong pressure on the ornament suggesting indicator of their size
What’re the intersex phenotypes
Sexual traits and sex determination aren’t fixed
Some female have intersex phenotype characterized by sexual organs called ovotestes (has both)
Because of increased androgen synthesis female intersex moles developed masculinized genitalia and become highly aggressive (duplication of CYP17A1 and inversion of FGF9)
what is the female-limited polymorphism and their dynamic sex roles
Females either have mal-like colouration or a distinct less flashy alternative
Eg. white-necked jacobin where both genders at young have ornament plumage and when grown females don’t have it are attacked less by other species
roles:
1. They shift throughout the breeding season
Eg. two-spotted goby male abundance declines by 10x while females are stable, decrease in male courting and increase in female courting
what is Competitional access to mates
- Adaptations help males actively compete with other males for mates (Fighting is most common)
- Sexual selection for fighting ability often leads evolution of large body sizes and armaments
- Conflicts are not always immediate but rather dominance hierarchy (costly to become dominant but if successful is considered adaptation)
what is the Alternative reproductive tactics (ART), when are they more likely to evolve, and what are the different types?
Different reproductive strategies within single sex of species
- dominant/territorial males (bourgeois)
- sneaker/satellite mimic males (parasitic) - never compete just opportunistically intercept mating opportunities or pretends to be females
evolve when:
a) Strong selection for body size
High growth costs (so they reproduce small instead)
b)Fair sperm competition
c)Leads to disruptive selection where intermediate phenotypes are less fit
types:
1. Genetic Arts: tactics ar fixed for life by genetic polymorphisms (spike size)
- Conditional ARTs: tactics that change based on environmental cues
a)Seen more when Growth costs are low
b)Relaxed competition for size (if size isn’t sole determinant for reproductive success)
c)Flexible switch
how are multiple ARTS displayed in populations
- Simultaneous evolution of multiple tactics
- Genetic fixed-for-life ARTS and conditionally flexible ARTS can coexist
- Occurs in restricted conditions:
a)Both genetic and conditional texts provide advantages under different scenarios
b)Often seen in species with complex mating system - Eg. Cuckolder males will evolve from all tactics (sneaker to satellite to mimic)
What is paternity assurance
Mate guarding which prevents them from mating with anyone else (costly)
Males of many species do this for days to avoid sperm competitio
What is sperm competition
- Males that adopt different mating tactics differ in securing mates but competition can continue afterwards
- Females can mate with more than one male in a short period
- If sperm has advantages in race to fertilize then number of spawning is not an accurate measure of fitness
- Males must compete and in some case their sperm must as well
what is the Runaway sexual selection model vs the Chase-away sexual selection model
runway
- If female choice create a genetic link between mate choice and trait, correlation leads to evolution of preferences for more extreme traits over time
- This generates runaway process where more extreme preferences end up too costly (they like long tails but eventually it becomes TOO long)
chase-way
- If male traits that attract female becomes disadvantage to females, they lead to females build resistance to it
What factors influence ART evolution
- Body size and size-dependent competition
- Territory availability
- Mortality risk
- Growth costs
- Sperm competition
- Frequency- dependent selection: type of natural selection where the fitness of particular phenotype depends on frequency of it is compared to other phenotypes
What are female mate choice benefits
and what is cryptic female choice
- Potential direct benefits (parental care, resources, safety)
- Potential indirect benefits (good looking son hypothesis)
cryptic:
- The ability of a female that receives multiple different sperms to choose which one gets to fertilize her eggs
- Post-copulatory sexual selection (even after egg/sperm fuse by just choosing to invest more resource or testosterone competition to preferred baby daddy’s egg)
- Can preferentially release or dilute sperm to skew male’s reproductive success
what is lekking behaviour
- Males gather at a specific location (Lek) and perform courtship displays, doesn’t provide resource/parental care and just have genetics to offer up
- Alphas usually take centre area with betas and such surrounding them
What are the evolutions of mating systems, what are things that drive it
Monogamy vs polygamy
- Ecological drivers
- Resource distribution
- Territory availability
- Parental investment
- Offspring survival - Reflects balance between ecological conditions, reproductive success, and the needs of offsprings for parental investment
what’re the different types of mating systems
Monogamy
- Only mates with 1 person
Polygny
- Male breeds w/multiple females
Polyandry
- Female has multiples baby daddies in one BREEDING SEASON
Polygynandry
- Both males and females have multiple partners with pair-bonds
Promiscuity
- Both have multiple partners with no bonds (all 1 nighters)
How is the type of mating systems determined
- Both sexes must weigh costs and benefits of mating decisions
- Males and females often have different motivations for attempting to mate multiple times
- Most are plastic and can vary among populations of the same species
- Populatings mating system is the result of one sex monopolizing access to other sex (the better their ability to gain access to mates, the more likely their evolution for multiple partners)
- The form of system evolved depends on which sex is limiting, and the degree to which the other sex controls resource access or monopolize mates
what’re the different types of monogamy (both are rare but do not equal each other)
Social monogamy
- 100% of offsprings produced by social parents (superb fairy wren)
- Literally an open relationship (mate, lives together, raise kids together but has flings with others)
- Usually leave territory before sunrise and mate with other birds before returning home
- 95% of nests have extra pair young (reduces infanticide
Genetic monogamy
- ACTUAL definition of monogamy, no affairs ever
- Florida scrub jays
Why be monogamous
- Costs of mating multiply is high for both male and female
- Costs for searching/mating multiple times- Risks of being killed by predator
- Chance of acquiring an std from some mates
- Mate limitation hypothesis:
- monogamy evolves when mates don’t roam/group making them hard to get (costly)
- Mate guarding hypothesis:
- monogamy evolves when individuals have the ability to inhibit their partner’s inner hoe
- Mate assistance hypothesis:
- Monogamy evolves when resources are critical to reproductive success that both parents have to be all in (takes 2 to tango)
- Infanticide hypothesis:
- forming bonds to provide paternal protection for offspring (buff baby daddy)
What is biparental care in monogamous species
- Male’s contribute in offspring welfare is major
a) European starling’s kids develop faster, higher catch rate too - Type of male care is limited compared to females (females can produce milk etc) so based on sexual selection theory, guys technically should focus on mating w/more girls
- If mate assistance hypothesis is correct
a) Mammals w/paternal instincts should be monogamous
b)Tested by California mouses showing that more pups are made together then when females are solitary
What is the evolution of monogamy and polyandry mammals
monogomy
- Breeding females are intolerant of each other and spread out
- This makes it hard for guys to keep track/protect all his hoes resulting in spending time with just one
polyandry
- Intense competition for females and territories, dudes are capable of forming teams to defends sites
- If females give all the dudes equal chances, mean fitness for each mate is higher than if one decided not to join the team (in a team ur fitness increases but u gotta share, no team=lower fitness than everyone)
What are the indirect benefits of polyandry
- Good genes hypothesis
- to produce good offsprings (reduced stillbirth, their clutches survive more than those produced by single mate males) - Genetic compatibility hypothesis:
- Increases odds of receiving genetically complimentary sperm (terms of fertilization, growth, survival) - Genetic diversity hypothesis:
- To increase the heterozygosity of either individual offspring or the group of offspring produced in a single bout (different group or different generations)
- Less chances of carrying recessive alleles that cause defects
- These mixed groups will survive bouts of disease/environments (stronger immune systems, different types of resistance)
- Inbreeding avoidance hypothesis:
Avoids inbreeding with their social partner
What are the direct benefits of polyandry
Additional resources hypothesis:
- Access to additional resources
- Gain multiple caregivers for kids (they cant tell which kid is theirs so they have to take care of all)
What is paternity dilution
Females mate with multiple males to confuse them over who the actual baby daddy is
what’re the different ways competition/resource determine male payoff in polygyny
Female defence polygyny hypothesis :
- evenly distributed resources = female groups with male guard (males fight for this position) to access resources/dilute predation
- social monogomy never occur
- dominat małe can control up to 80% of mating by driving away subordinates
harem defence polygyny:
- a form of female defence polygyny, females are socially bonded, male can monopolize a whole group (zebra’s)
Resource defence polygyny hypothesis:
- clumped resources = females attracted to it and males easily guard resources + female by ext.
lek polygyny hypothesis:
- resources distributed heterogeneously and no female groups formed = males wait for women to come to them
- their lek circle is for display at intersections where females must pass
- unequal mating success, older males are in centre and females compete to mate w/that one
scramble competition polygyny hypothesis:
- resources distributed heterogeneously and no female group formed = males seek them out
What is the female distribution theory
- Measured male territories and female foraging ranges
- Females hunting range is so large it overlaps with multiple males’ territories, creating a polygynandrous system
- When resources are supplemented, female range decreases, also decreasing amt of social mates they have
what is the polygyny threshold
- The point where females gain higher fitness by mating w/taken male than a bachelor right after (prefer bachelors ass they have more offspring/don’t share territory)
- Manipulated pairs of red-winged blackbirds found females chose best nesting location even if it meant joining a harem (had 2x amt of kids)
what is the evolution of lek polygyny
Hotspot hypothesis:
- Males make their clusters in areas traveled by females
Hotshot hypothesis:
- Subordinates cluster around the hotshot to have a chance at female interaction
Female preference hypothesis:
- Males cluster cause females like the male accessibility of male leks
How is lek polygyny tested what are the results
Artificial leks populated by painted decoys are placed with varying amts of sex combos to see how many live birds are attracted to each
Rejects hotspot but not hotshot or female preference
- Female decoys failed to attract male clusters
- Male decoys especially large clusters did attract females
what is the scramble competition polygyny
When receptive females and their resources are dispersed, males will look for them before others can (scrambling to find them), persistence beats aggression
what is the prerequisite for monogamous mating systems, what are the two preconditions needed for the evolution of polygamy?
prerequisite for monogamous mating system
- economic defendability of a mate
preconditions for evolution of polygamy
1. environmental potential for polygamy (EPP)
- species/resources that can attract multiple mates needs to be energetically defendable
- ability to capitalize on EPP
- dictated by parental care
What’re the types of interactions between individuals
collective behaviour
- synchronized movement of individuals following basic interaction rules
interaction:
- non-independence between individuals’ movements
what’re the types of social behaviours
Mutual benefit
- Both receive benefits
- Hard to identify benefits to both parties and can be mistaken for kin-selected benefit
- Clownfish wait for a vacant breeding position (being dominant isn’t beneficial but chasing away others is also not costly)
Altruism
- recipient gets fitness benefits while donor gets a cost
Selfishness
- Donor benefits, recipient doesn’t (kleptoparasitism, stealing from someone else who did the collecting)
Spite
- Neither the donor nor recipient benefits (rare)
- not favoured by natural selection but could be adaptive
What is the social Network Analysis for animal behaviour
- individuals form relationships that are not always equal and changes over time
- individuals represented as odes while their connections are Called edges, more connections = more edges, the stronger the connection, the thicker the node
what is altruism and reciprocity, what is indirect reciprocity
Direct
- helpful actions that is repaid later (costs of helping is modest but delayed benefit is great)
- only happens in species who’ll know each other long enough for the payout
- not common (vulnerable to those forgetting to repay, this defectors reduce evolution of reciprocity)
indirect:
- helpful action repaid later by someone else (witnesses will wanna help you out later)
what is the prisoner’s dilemma, How are the payoff for responses ranked in prisoner’s dilemma
prisoner’s dilemma
- game theory construct where fitness payoff are set to be mutual cooperation generating lower return instead of defection
payoff ranking:
1. defect while other cooperates
2. both cooperate
3. both defect
4. cooperate while others defect
optimal response is to always defect
- but if individuals can use “tit-for-tat_ and go back and forth, rewards will accumulate and exceed reward for a single defection
what is cooperative breeding
multiple individuals care for young together
- on 5% of mammals and 10% of birds/fish
- characterized by presence of non-breeding helpers that aid in parental care (alloparental care)
- these helpers are male in birds but females in mammals (capable of breeding but don’t, usually the older child)
what are the evolution hypothesis of cooperative breeding
kin selection hypothesis:
- indirect fitness benefits delay independent breeding and instead helping
group augmentation hypothesis:
- survival/reproduction is better by living in a larger group (delayed reciprocity, hard to test, likelihood of territory inheritance)
ecological constraints hypothesis:
- when breeding resources are limited, individuals delay dispersal and remain in the territory to help raise relatives (limited resources means it’ll be even tougher alone)
life history hypothesis:
- historical traits like juvenile/adult survival impacts cooperative breeding evolution (create’s surplus of individuals in a habitat)
benefits-of-philopatry hypothesis:
- benefits of delayed dispersal outweighs costs associated with independence
temporal variability hypothesis:
- environmental uncertainty promotes cooperative breeding because having helpers at the best allows birds to breed successfully under both good/bad conditions (reproductive insurance)
- occurs in arid environments where rainfall is low, variable, and unpredictable
what are the costs and benefits of cooperative breeding
- primary helpers work the hardest which translates to lower probability of surviving to return to breeding grounds
- primary helpers raise fitness indirectly while secondary raise theirs directly
- only 67& of surviving primary helpers find mates in their 2nd yr
91% of secondary helpers go on to breed (bonds with the women they’re helping = increases their access to mates)
what is load-lightening in terms of cooperative breeding
helpers reduce the workload of parents in offspring care
- direct benefits to the breeders can also explain why cooperative breeding systems can evolve
- presence of helpers allow parents to reduce their workload
pay to stay
what’re the individual differences in cooperative behaviours
can be heritable and repeatable but behaviours are more plastic than heritable
1. animal personality:
- individual behaviours that are repeatable through time, consistency within individuals across contexts
- behavioural syndrome:
- behavioural consistency within individuals across contexts. individual behaviours that are repeatable through time
species that exhibit cooperative breeding are ideal for studying fitness effects of personality because they can adopt different roles that vary in success
- studies wanted to ee if specific personalities are more likely to become a breeder vs helper, proof for this is limited
what is the difference between obligate and facultative altruism
obligate:
- helpers cannot reproduce and only gain fitness benefits indirectly
facultative:
- helpers retain potential for reproduction, maximizing their lifetime inclusive fitness as a combination of both direct/indirect fitness
- high potential for reproductive conflict and structure of society influences the potential its potential
what are social organizations in terms of cooperative breeding
- cooperative breeding species vary in social organizations and reproductive skew
singular breeding: social groups contain only a single breeding female and reproductive skew is high
plural breeding:
- social groups contain multiple breeding females and reproductive skew is lower
- multiple females breed w/multiple males
- offsprings tend to be less related to each other
- groups consists of a mixture of related and unregulated individuals
- reproductive conflict can be high for breeding positions because there are more breeding opportunities
explain kin structure and relatedness
- Avian mating systems are fluid and promiscuous
- in species where nest contain s kids from multiple baby daddies, offsprings are less likely to engage in cooperative breeding with helpers, instead preferring monogamous species
- in social species that form kin groups, mating and social systems go hand in hand
what is the difference between communication, signal, and cue
Communication:
- transfer of info between
sender/receiver that affects current/ future behaviour and fitness of one or both
Signal:
- coevolved message between sender/ receiver containing info (evolution of comms requires signal perception)
Cue: unintentional and unselected transfer of information
what is info, why is it needed
- Stable information includes things like species identify, sex, or toxicity
- Physiological condition or dominance rank can change
- critical for survival/reproduction
- communicate abt what’s around them and themselves
- interpretation is critical as it influences fitness of both parties
- used ass warning sounds (what, where, when)
what is the evolution of signals
Preexisting trait hypothesis:
- Signals evolve through senders preexisting traits( behavioural, physiological, or morphological) that already provide informative cues to receivers and can be modified into a signal via ritualization)
Preexisting bias hypothesis:
- Signals evolve through receivers preexisting biases(biases in their sensory systems that detect some features of the world better than others)
- sensory exploited by senders
what is the panda principle
Evolutionary transitions occur by changing
structures piece by piece as selection does not start from scratch but acts on what already exists
*panda thumbs is a highly modified wrist bone (their ancestors used it for running but when they evolved into herbivores, it changed)
what’s an example of preexisting bias
Trinidadian guppies:
- males can’t see orange and gets it through plants but can synthesize red pigmentation (drosopterin)
- females prefer orange dudes as a product of evolved visual sensitivity to the colour
what’re the communication frameworks
Honest signaling:
- both sender and receiver obtain a fitness benefit
- large males have an easier time making threat displays
- there is a cheap production cost but maintenance cost due to social enforcement is higher
Deceitful signaling:
- sender receives a benefit and receiver pays a cost
- senders receive benefits by manipulation
- carnivorous female fireflies lights up to attract males then eat them
Eavesdropping:
- sender pays a fitness cost and receiver gains a benefit
- when predators/parasites eavesdrop, costs are imposed on legitimate sender
g. some lyre birds will eavesdrop and create illusions of predators to keep females from leaving display area
- this has shaped sender behaviours (songbirds starting producing calls at higher frequencies)
what is multimodal signalling, give an example of a species that does this
- many species use a different sensory modalities to signal (tactile, visual, acoustic, chemical etc.)
Multiple message hypothesis:
- Different signaling modalities convey
different info
Redundant signal hypothesis:
- Diff modalities independently convey
the same info, providing insurance for errors or environmental noise
example:
- peacock spiders exhibit visual and vibrational signals and ALSO haas oramental tails
- both used to court females
why does deceitful signalling occur
Novel Environment hypothesis:
- the environment is sufficiently
different from the one where the behaviour originated so that there’s enough time for adaption to happen
Net Benefit hypothesis:
- a sensory mechanism that result in fitness losses for some under certain circumstances but doesn’t erase the fitness gain by
receivers for reacting to a sender
aka evolves when costs for producing false response are lowering than that of failing to respond
What is learning in animal species
- individuals rapidly learn to forage in more efficient manners as they gain experience
- only occurs if it is adaptive because its costly to learn
what has an effect on the evolution of learning
- environmental stability
a) in dynamic world
(habit A= 50% probability of high fitness
Habitat B = 50% high fitness)
b) fixed world
(habitat A = 100% while habitat B=0%)
- if environment is regulated, learning decreases and evolution is fixed)
- usefulness of past experience
- if reliability increases, learning will be favoured
what is habituation
- reduction and lack of response to stimulus over time
- habituation to useless stuff is good cause then they can focus on important stimuli
How does learning occur (neuropathology)
- changes in neurotransmitters
- number of synapses between neurons
what is imprinting
- rapid learning during a short amount of time but has long lasting effects
- vulnerable offsprings benefit from this so they can recognize parents and remain close
- the IMHV in the brain has important role in memory related to imprinting (lesions/blockers will prevent imprinting
eg. baby geese imprinted on Konrad’s boots
what is neural plasticity? what are dendritic spines in relation to learning?
- neural plasticity: structural changes in number of synapses and they’re chemical strength between neurons
- these changes are dynamic due to formation/elimination of dendritic spines (small protuberance that receive synaptic inputs)
- more knowledge = more dendritic spines formed
what is classical conditioning vs operant conditioning
Classical
- a type of learning where Novel stimulus is paired with an existing stimulus and elicits a irate response (dogs salivate when they see food and owner who feeds them)
operant:
- process of associating behaviour w/a consequence
any of these types can occur:
1. positive reinforcement: behaviour is more likely due to presentation of a stimulus
- negative reinforcement: behaviour more likely due to removal of stimulus
- positive punishment: behaviour less likely cause of presentation of stimulus
- negative punishment: behaviour less likely cause of removal of stimulus
what is learning predators and what is learning curves
- certain species like the damsel fish make association between chemical alarm cues and odours of hetero-specific fish o learn their predators
learning curves:
graphical rep of change
what is social learning, and how do some learn about food patches
- others r info sources for learning
- may be favoured if energetically efficient
- black tailed prairie dogs learn anti predator behaviours from adults
- local enhancement: strategy where they look for presence of others to indicate focus areas
- public info: obtained by activity of others showing quality of environment
what is behavioural teaching, evidence?
experienced individual facilitates learning of newbies
- teacher will modify his behaviour only while pupil is present
- the behaviour is costly for the teacher
- pupil acquires knowledge rapidly through actions of teacher compared to otherwise
eg. ptarmigan birds learn what to eat quickly (hens drop small food and bop their heads when chicks are nearby)
what are behavioural traditions, who uses them
difference in behaviour among populations that are transmitted between generations through social learning
- dolphins use marine sponge to locate submerged prey
- these sponge tools are only found in dolphins near shark-bay
what is animal culture and what are the potential explanations
differences in multiple traditions among pops
explanation:
- genetic basis
- ecological differences
- social learning
what is cognition, and how its it tested
- ability to acquire, retain, process, and use info (can evolve more applications)
- early work used tools and observed its manipulation to achieve a goal (problem-solving behaviour)
- mirror self-recognition test: mark placed on face of individual who its placed in front of a mirror.
- if individual directs any behaviour towards it, demonstrates self-awareness (most species don’t pass) - numerical competency: ability to recognize numerical info
- ability to estimate amt of objects/events
- they can only count “more” of somm but not “less”
what is numerical discrimination/competency? what is used to assess numerical discrimination
Magnitude effect:
- many spices can distinguish between small quantities (1-3 rather than 6-8)
disparity effect:
- easier for them to select larger quantity when the difference between options its large (easy to distinguish 2-5 not 4-5)
- numerical discrimination tests used
- tested if species exhibits numerical discrimination and whether training was required for it
what Is memory in terms of cognition, how do you characterize memory capabilities?
- cognition involves retention of info, thus memory its the most important characteristic of it
- memory benefits locations recognition, behaviours
- examines food caches created by animals (stored for later)
what is long term memory? what is behavioural flexibility, how is it measured?
- ability to recall past events and provide quantitive measures for cognition (length of time between events is recorded)
- eg. memory of old food patches etc.
behavioural flexibility:
- approach of cognition assessment based on graded manner
- it measured ability to alter behaviour in response to environmental stimuli
- measured by ability to innovate
- ability to quickly inhibit a previous behaviour when conditions changed
- reversal learning:
- after learning to associate 1 stimuli/reward, the conditions are reversed and individuals needs to associate reward/alternate stimuli
what is the relationship between cognitive ability and reproduction, what is the relationship with cognitive ability and mate preference
- used reversal learning test and spatial memory tasks to asses cognitive function of an individual
- studied those individuals to see how many offspring’s they had (positive correlation between the two )
- female initially liked the unpreffered male base on just visuals and stuff
- but once the preferred was trained to open boxes, the female preferred intellect
what is the relationship between cognition and the brain?
what part of the brain is spacial memory associated with?
- brain size its positively correlated to body size
- increased brain size allows for greater behavioural flexibility
- spacial memory is associate with the hippocampus(hippocampal formation in birds)
- harsher conditions show higher caching ability/higher memory/larger brains (heritable)
eg. bird Brians have reported new foraging innovations, also good caching memory
What are the key aspects of Foraging behaviour, what is it influenced by?
- goal oriented
- dynamic,
- involves decision making
by:
- energy optimization
- food availability and nutritional needs
- predation risks and competition
- social status
- level of cognition
- habitat features and human influence
what is the optimal theory and what is the optimal foraging theory and it models, what are the factors that affect it
optimal
- organismal attributes are optimal and generates possible adaptive values for fitness of those that have it
optimal foraging
- predicts how animals maximize fitness while foraging (cost benefits)
models assume energy maximization is all that matters but they do not always select food as efficiently as possible
factors:
- biology affect foraging behaviour (oystercatchers don’t always get the biggest one cause its covered in barnacles)
- predation risk will result in preferred temporary small gain instead (life-dinner principle)
how do organisms search for food
- chooses among places rather than among types of food
marginal value theory:
- animals should stay in patch until its marginal benefit of feeding declines to equal the average intake rate of the enviornment
explain what net caloric intake is, what did the whale study show
caloric costs of gathering food is less than caloric benefits gained by eating
whales:
- whales dive for 15min when foraging (cost = 60K KJ cost) but will gather 30mil KJ in benefits
what is the landscape of fear
In terms of predation risk in changing foraging behaviour,
foraging behaviour changes when introduced to predators, individuals will lower energy intake to avoid risk of getting killed (move to different areas or somm)
what’re the types of morphological features that are selected for by species in term of mate selection, and what can they signal
ornaments attraction(colour, size)
or
armaments that facilitate competition (antlers, horns, claws)
they signal good health and diet (high quality)
what is predation risk at broad, intermediate, and fine scales
broad
- risk in diff areas influence prey’s choices in home range
intermediate
- spatial variation risks within home range will affect prey’s space use
fine
- direct presence of predators = prey reactive avoidance and anti-predator behaviours
what is reproductive suppression vs reproductive senescence
suppression
- removes opportunity for competition over breeding (eg. naked male rats limit breeding to just the queen and several kings in the nest chamber while subordinates don’t ovulate)
- female dominance is maintain by stress-mediated hormone suppression
- males police each other through nose shoving
senescence
- reduced reproduction capacity as organisms age (related to cell deterioration, older = high risk so they become helpers instead)
what is the ecology of fear?
landscape fear?
ecology
- effects of predation threats to behaviour
landscape
- physical landscape effects perception of threat (physical is like amt of escape routes etc)
- predation landscape is actual threat of predators in area
what’re the type of anti-predator behaviour
proactive (adjusted to reduce risk and leads to passive social defence or land use)
active (adjusted when threat is imminent)
what is active social defence and what is vigilance in relation to it
- actively searching for, responding to, or attacking predators (mobbing)
- is costly and risks injury or attraction of more predators
vigilance
- addition eyes to search for predators (subordinate help)
- can be cooperative between specifics (oxpecker bird onyx of rhino)
what is passive social defence
Dilution effect hypothesis:
- being in a group = individuals are less likely to be hunted
Confusion effect hypothesis:
moving as a group reduces
likelihood of predation cause they can’t single them out
Selfish herd hypothesis: individuals in a group
reduce risk by using others as a barrier (putting someone else between u and the door in case of burglar)
what are super predators and what is the anti-super predator behaviour
humans are a form of super predators (overhunts a species compared to regular predation)
anti-behaviour
- increased vigilance, grouping behaviour, permanent avoidance
- this leads to reduction in foraging and few offsprings
what is the evolutionary stable strategy
when single strategy for a population can’t be invaded by a rarer strategy (a set of behavioural rules that when used by a certain percentage of the population cannot be replaced)
relevance of isotopes in foraging and diet
- isotopes (C, N, S) naturally occur and show where animals lie in the food web (it accumulates with trophic levels)
- C distinquishs between food sources
- S reflects habitat use
what are the human influences on animal foraging behaviour
- Habitat alteration and destruction
- Resource exploitation
- Human-introduced species
- Climate change and environmental stressors
- Behavioural conditioning
- Ecological contaminants
- Agricultural practices
- Cultural and historical exploitation
what affects habitat selection
abiotic factors
- climate, topography, resource availability
biotic factors
- predation risk, reproduction, competition
intrinsic factors
- learned behaviours (preferences based off experience and social interactions)
- genetic predisposition
- personality (aggressive species that do better in this area?)
what is territoriality and what’re its benefits and costs?
why do challenges made by an individual for territory often end in defeat quickly if benefits are so great for having territory?
defence of an area
costs:
- time/energy/injury or death
benefits:
- access to resources, survival, better fitness
why it ends:
- arbitrary contrast resolution: residents always win
- resource-holding potential: residents have an edge in combat
-payoff asymmetry: residents who temporary leave for less than 3 mins can fight off intruders, the longe they’re away, the longer they have to fight to reclaim territory
how is aggression regulated and what is the winner effect
- aggression is associated w/plasma androgen hormones (testosterone)
winner effect
- success in aggressive fights for mates/territoy enhances fitness (testosterone levels are a deciding factor)
what is the challenge hypothesis
male/male interactions increases testosterone and sustain aggressive behaviour
- developed to explain trad off between completion and parent care
- testosterone only increases for short periods of challenging
wat is anthropocene
Anthropocene
- human activities major influence on ecosystem (climate change, land-use, pollutants)
- humans alter biotic interactions (invasive species, harvesting, urbanization)
what is the importance of behavioural changes
- animals use it to adapt to the environment
- changes in animal behaviour affects its role in ecosystem
- understanding this is essential for effective conservation actions
what is daily activity timing and what is timescapes
timescapes:
- captures variation in predation risk, seasonal changes etc
- humans creat changes that affect timing of predators, competitors etc
- sensory pollutants may disrupt stimuli animals use to structure their timing (artificial light to turtles)
daily timing:
changes behaviour based on timescales
what’re the ecological effects of novel activity timing
- effects individuals and whole ecosystems
- individual level effects include physiology
- community level: increase or diminishes competition, predation, disease spread
- pop level = altered activity timing will lower recruitment of ecosystem stability, prey forage at diff times then predators go hunting)
- ecosystem level = changes nutrient flows if it disrupts processes like herbivory
what is biogeographic timescape compression
low latitude human chaos affect larger ecological affects
human recreation leads to lynx cats becoming more nocturnal
temperature Changes = flies shift activity level under high temps
sensory pollutants (eg. lights) confuses birds and make them more active at night around light pollutants (cause they still think its day)
habitat changes make small mice more active in invasive areas
how does tech offer new ways to study behaviour
- allows for newer approaches to study broader ranges of species by making unbiased tracking easier
- eg we use to visually observe and track but now we have sensors that track and record for us (seism sensing (measuring sound vibrations is more accurate now))
