Chapter 13: Social Behavior and Sociality Flashcards
4 general kinds of social behavior that can take place between two individuals
1) mutual benefit 2) altruism 3) selfishness 4) spite
what is mutual benefit
when both individuals receive a fitness benefit. (+/+)
what is altruism
when the recipient receives a benefit and the donor pays a cost (-/+)
what is selfishness
when the donor benefits and the recipient pays a cost (+/-)
spite
occurs when both the donor and recipient pay a cost (-/-)
cooperation includes both ___ and ___ ___
altruism and mutual benefit
describe the phenomena of mutual benefit in the paper wasp polistes dominula
Females that help an unrelated foundress female have a chance of inheriting the colony from the dominant foundress. Inheritors often acquire a well-defended colony with helper, and as a result they generally reproduce more successfully than solitary foundresses so even though helpers are unrelated, they still help the queen reproduce and take care of the colony because they will receive a reward (inheritance) later on. (postponsed cooperation
post poned cooperation
when an individual eventually gains access to a resource controlled by another individual because of its prior help
explain the stange mutual benefit seen in buntings
An unusual form of cooperation occurs in Lazuli buntings, where yearling males (dull coloured) are tolerated by dominant males (brightly coloured) and allowed to establish a neighboring nesting territory. the dominant males often mate with the females that belong to the dull males, and the dull males often end up helping rear some of the dominant males chicks. BUT; he still gets a benefit because he raises some of his own, too. If he were to be intermediately colored, it is likely the dominant male owuld push him so far out to a bad territory that he wouldn’t mate at all. therefore it is a mutual benefit because both dominant and yearling male get increased reproductive access.
explain cooperativity and mutual benefit in Manakin birds
males cooperate together to perform a duet for a receptive female to put on a “grand show.” they often partner up with a “friend of a friend,” or other males of neighboring leks (not complete stranger males). of the duo, one male is alpha and the other is beta. if, after the performance, the female wants to mate, the beta bird takes off and lets the alpha copulate with the female the beta male receives his benefit later; when the alpha male dies, the beta male gets to be the alpha, and he’ll have a new “beta.” He copulates as frequently as his predecessor did, presumably because females attracted to the duo in the past return to the display arena when receptive
Altruism among non-kin is rare among animals except when the benefits are _____
Altruism among non-kin is rare among animals except when the benefits are POSTPONED
In long-tailed manakins, some superficially self-sacrificing behaviours advance the reproductive chances of at least some patiently helpful individuals that survive long enough to graduate to alpha status: this arrangement is called:
postponed cooperation
reciprocal altuism
individuals that are helped generally return the favors the receive- eventually. also just known as reciprocity.
reciprocity will occur only among individuals that remain together long enough for:
the helpful act to be later repaid.
example of reciprocity in primates.
grooming behaviour of group-living primates where the roles of groomer and groomee are switched over time; OR grooming (by the female) may be exchanged for protection by the male
indirect reciprocity
when third part observers that witness a helpful act are more likely to help those that have helped others. can be used to explain why some individuals develop copperative reputations.
discuss reciprocity in vampire bats
Blood meal sharing in vampire bats is explained by reciprocity. Individuals ensure against future starvation if they share blood with a neighbour after a successful night of feeding, assuming that another individual in the colony reciprocates with them after they have had an unsuccessful night of feeding some time in the future.
why is reciprocity rare
because of cheating. cheating is more beneficial for the cheater because they recieve and dont need to give this is known as the prisoner’s dilemma
basics of game theory
1) A game is an interaction between two or more players 2) Each player chooses between two or more strategies 3) For every set of choices, each player gets a specific payoff
pareto optimal and nash equilbrium of game theory
pareto: both prisoners cooperate and receive a small punishment each - you cannot increase the reward to one player without decreasing the reward to another nash: both defect and the punishment for mutual defection is 5 years in prison The situation where NO player has anything to gain by changing only their own strategy
____ is the evolutionarily stable strategy
DEFECTION. Which is too bad because both would do better if they both cooperated and kept their mouth shut. This is a barrier to cooperation. In biological systems, everyone benefits from being in a cooperative group, but each can do better by defecting. Cooperation is (sadly) often unstable because of the constant worry of cheating and not receiving help after giving
If the prisoner’s dilemma is conducted over many trials, instead of immediate defection, what new strategy is involved?
tit-for-tat: cooperate until someone screws up, then try and forgive and keep going better than constant cheating or else if you purely defect, the other person will continue to defect as well.
kleptoparasitism
common form of selfishness that involves stealing food from others.
selfishness in animals use ____ ___ to manipulate others to perform actions that will ____ their fitness
selfishness in animals use COERCIVE TACTICS to manipulate others to perform actions that will INCREASE their fitness
example of spite
hard to find examples of spite because it isn’t evolutionarily favored by natural selection since no one benefits. often requires higher thinking processes. seen in monkeys where when held in captivity and one monkey receives more food than another ,the mad monkey will punish the monkey with more food. this is spite because the mad monkey also doesn’t benefit from this processes. hes just mad but doesn’t get more food in the end.
___ ____ is central to the evolution of cooperative behaviors among relatives (ex/ soldier wasps will kill larvae that they aren’t related to rather than sister larvae)
kin recognition
individual variation in animal behavior is studied under two broad differences in behavior:
1) animal personality: consistent themes of behavior 2) behavioral syndromes: behavioral coorelations among dif contexts
explain the costs of group living in cliff swallows. What benefits balance it out?
Cliff swallow parasites: larger swallow colonies have higher infestations of parasitic swallow bugs. That is a cost of social living. The counterbalancing benefit appears to be enhanced FORAGING SUCCESS, since there are more ‘eyes’ to to locate food. another one is THERMOREGULATION: more members allow for heightened ability to keep warm
in lekking species, there is a huge array of reproductive success in males. why may it still be beneficial for males to gorup together despite the fact they are competing between one another
because if more males stick together, more females are attracted. despite competing against one another, there are now more females in the area to begin with.
explanations for cooperative breeding
- KIN SELECTION HYPOTHESIS 2.GROUP AUGMENTATION HYPOTHESIS 3. ECOLOGICAL CONSTRAINTS HYPOTHESIS 4. LIFE HISTORY HYPOTHESIS 5. BENEFITS OF PHILOPATRY HYPOTHESIS 6. BET-HEDGING HYPOTHESIS
kin selection hypothesis
Indirect fitness benefits explain why some individuals delay independent breeding and become nonbreeding HELPERS that aid others to reproduce
turkeys fit in with ___ ____ hypothesis of cooperation
kin selection hypothesis of cooperation. There is background genetic relatedness forALL MALES in the population, the relatedness between subordinate males and their dominant partner (coalition), and the relatedness between half siblings, full siblings and mothers and their offspring. Male turkeys that COOPERATE to find mates tends to be HIGHLY RELATED, with an average relatedness close to full siblings: brothers help brothers find mates!
group augmentation hypothesis of cooperation
Individuals survive or reproduce better by living in larger groups
ecological constraints hypothesis for cooperativity.
When resources required to breed successfully are limiting, individuals will delay dispersal and remain in their natal territory to help raise their relatives
Life history hypothesis
Specific life history traits such as high juvenile and adult survival paly a role in the evolution of cooperative breeding by creating a surplus of individuals in a given habitat
Benefits of philopatry hypothesis
The benefits of delaying dispersal outweigh the costs associated with attempting to disperse and breed independently
Temporal variability hypothesis
Environmental uncertainty promotes cooperative breeding because having helpers at the nest allows birds to breed successfully under both good and bad conditions
Bet-hedging hypothesis
Having helpers at the nest reduces environmentally-induced reproductive variance
Explain inclusive fitness and the pied kingfisher
African pied kingfishers nest in colonies alongside lakes and rivers Some year-old males DO NOT find mates and become PRIMARY HELPERS to their MOTHERS, helping to raise siblings
Primary helpers deliver more calories per day in fish to a nesting female and her offspring than do secondary helpers, which are not related to the breeders they assist.
Alternatively, they could help unrelated pairs raise offspring (secondary helpers), or they could not help anyone and delay breeding (delayers)
Being a primary helper is hard work and the survival of primary helpers is LOWER than that of secondary helpers or delayers, BUT THEY HAVE ADVANTAGES: Although being a primary helper reduces survival to the second year, the extra inclusive fitness from being a primary helper (0.58 units), more than compensates the loss of direct fitness in the second year. (0.58+0.41 in primaries is larger than the 0.84 benefit in secondaries)
Image: Primary helper with the brood present -à 1.8 kids of the alpha SURVIVE. R=0.32 in relatedness. Therefore the inclusive fitness benefit that primary helpers get when they help raise the kids is 0.58 for first year benefit.
Secondary helpers do not get any inclusive benefit in the first year- they help the alpha parents raise 1.3 more kids, but there is no degree of relatedness to them.
Under the group augmentation hyopthesis, delayed ____ rather than ___ ___ might explain cooperative breeding in some species.
Under the group augmentation hypothesis, delayed reciprocity rather than kin selection might explain cooperative breeding in some species.
delayed direct benefit of INHERITING a territory not only influences why some individuals help, but also influences whome those individuals helpa nd how much help they give. this can explain why there is cooperative breeding in species in which kin structure is low and yet helping behavior persists.
this could involve the recruitment of new group mates, even those unrelated to the helpers, as well as through the retention of offspring.
In group augmentation hypothesis, direct benefits to the breeders – not just helpers – can also explain how cooperative breeding systems can evolve via ___ ____ .
Direct benefits to the breeders – not just helpers – can also explain how cooperative breeding systems can evolve via load lightening. There are direct benefits from the assistance from the helpers. This lightens the load off the primary pair.
permutation of group augmentation hypothesis. explain
PAY TO STAY HYPOTHESIS. parents require individuals to help as a form of payment for remaining in the group
explain the pay to stay hypothesis in cichlids
cichlids tend to form non kin social groups, and paying via helping may enable helpers not just to remain in the group, but also inherit the territory.
Cichlid: extra pair cichlids have to help raise larvae and defend the territory if they want to stay in the territory .
explain the pay to stay hypothesis in the superb fairy wren
presence of helpers in the group at the time of egg laying allows the female to lay lighter eggs. this cutting back of egg investment because of laying allows females to live longer and thus have more lifetime opportunities to reproduce
helpers thus boost the number of siblings created by their mother, addingto the helpers indirect fitness if they are related to the adult female they are assisting/
Ecological constraints: When resources required to breed successfully are limiting (habitat saturation), individuals will ___ ____ and remain in the territory where they were born to help raise their relatives
When resources required to breed successfully are limiting (habitat saturation), individuals will delay dispersal and remain in the territory where they were born to help raise their relatives
ex/ seychelles warblers seen in the mate guarding chapter.
explain habitat saturation in seychelles warblers
habitat saturation is when there is a limited number of breeding sites because most of the best sites are already occupied by other members of that species.
In image; Population territories is heading to a carrying capacity (120 terriroties on the island). This splitting of the lines indicates cooperative breeding. Kids were delaying moving from the nest”delaying dispersal” and help take care of siblings rather than moving out and trying to find a territory on their own that might not exist because of environmental limiting factors. There is population growth desbite habitat saturation
habitat saturation is involved in the ___ ___ hypothesis, which is:
the hypothesis that specific life history traits, suh as high juvenile and adult survival, play a role in the evolution of cooperative breeding by creating a surplus of individuals in a given habitat.
in seychelles warblers, habitat saturation often results in delayed dispersal. When do helpers actually leave?
If one parent is replaced (dies) or both parents die, then the kids tend to leave. This is because if they stayed, they would no longer be helping their relattives. Theres no inclusive fitness benefit.
young warblers also left home if their parent’s natal site were of low quality, and they didn’t benefit much from inheriting it
in addition to the environmental constraints hypothesis, seychelles warblers also fit the ___ of _____ hypothesis, which staes:
the benefits of philopatry hypothesis, where delayed dispersal outweighs the benefits of attempting to disperse and breed independently.
The benefits of philopatry and ecological constraints hypothesis are pretty much the same idea: BOP emphasizes indirect reproductive benefits; EC (ecological constraints) emphasizes the cost of lost direct reproductive benefits when territories are limiting. Basically the same idea.
Temporal variability hypothesis
Environmental uncertainty promotes cooperative breeding, as helpers at the nest help successful breeding EVEN UNDER adverse conditions
evidence of the temporal variability hypothesis.
Cooperative breeding is often observed in birds breeding in desert or semi-desert environments, and there is increased success in years when rainfall and food availability is LOW.
Bet hedging hypothesis
Emphasizes the importance of reproductive variance. Reproduction is essentially multiplicative: lower variability is correlated with higher evolutionary fitness
in the bet hedging hypothesis: having helpers at the nest reduces environmentally induced reproductive variance.
Rule of thumb: natural selection maximizes ____ ____ reproductive success
Variable reproduction: 1 in bad years: 3 in good years
Constant reproduction: 2 in bad years: 2 in good years
Arithmetic mean is the same (2.0) but the geometric mean(square root of multiplicative outcome over the years) of constant reproduction is higher
natural selection maximizes the geometric mean reproductive success
Variable reproduction: 1 in bad years: 3 in good years
Constant reproduction: 2 in bad years: 2 in good years
Arithmetic mean is the same (2.0) but the geometric mean(square root of multiplicative outcome over the years) of constant reproduction is higher; therefore it pays to have LOW REPRODUCTIVE VARIANCE BECAUSE THE GEOMETRIC MEAN IS HIGHER.
example of conflict in cooperative breeding.
Naked mole rats: a eusocial mammal where reproduction is restricted to a single large “queen” and several large “kings” in a colony that may number up to 200 individuals
The queen mole rat is a tyrant, pushing other members of the colony around, inducing stress in subordinate males and females. This bullying suppresses the production of sex hormones in subordinates: they are forced to forego reproduction.
Subordinates must either leave (a risky strategy) or accept subordinate non-reproductive status.
The sterility of the subordinates is not voluntary. (The female secretes hormones and suppresses their reproductive hormones.) –> example of conflict.
