Midterm 2 Flashcards
What are the three basic life problems that primates must overcome?
Finding food, avoiding being eaten, dealing with others
What is predation?
An obvious threat to survival and reproduction
Who are the main predators of primates?
Raptors, large cats, large snakes
What are anti-predator strategies?
- Cryptic
- Conspicuous but toxic
- Conspicuous but startling
- Conspicuous but confusing
What is the dilution effect in grouping behavior?
It is the reduction of individual risk of predation in larger groups
What are the anti-predator benefits of grouping?
- More eyes = better predator detection
- Reduced per capita vigilance costs
- Better active defense
- Dilution effect
What are the costs of living in a group?
- Larger groups are more conspicuous to predators
- Increased food competition
- Increased social competition
- Increased risk of disease transmission
What is resource defense in the context of grouping?
Sociality is an adaptation to improve resource access
What factors determine female distribution in relation to food?
- Quality of food
- Scarcity of food
What is the prediction of resource defense regarding group composition?
Groups should be composed of female kin
What is the relationship between group size and feeding competition?
As group size increases, feeding competition within the group also increases
What does the term ‘intra-specific competition’ refer to?
Competition among individuals of the same species
What influences diet choice in primates?
- Body size
- Food quality and availability
What are the four basic primate diets?
- Frugivore
- Folivore
- Insectivore
- Gumnivore
What is Kleiber’s Law?
BMR = 70(Body wt.)^0.75
What is the relationship between body size and metabolic rate?
Larger species need fewer calories per unit of body weight
What are the implications of gut capacity on diet choice?
Gut capacity influences food digestibility and feeding strategies
What is the difference between a home range and a territory?
Home ranges can overlap, while territories are defended against conspecifics
What is the territoriality index (D)?
D = DPL/d’
What does a D value of D ≥ 1 indicate?
Permits territoriality
What are the two critical aspects of social behavior?
Mating and parenting
What are the different mating systems observed in primates?
- Solitary
- Polygyny
- Polyandry
- Monogamy
What is the cost of sex related to?
- Cost of meiosis
- Cost of mating
What are the benefits of sexual reproduction?
- Recombination
- Avoid accumulation of deleterious mutations
Why do females generally invest more in reproduction than males?
Female gametes are more energy expensive to produce
What is the life history strategy for male mammals?
Infinite gamete supply and limited investment in offspring survival
What is the significance of female dispersal in social systems?
Females distribute according to resources and predation
What is the relationship between food availability and territoriality?
Territoriality occurs when benefits outweigh costs
What role does sexual dimorphism play in primate behavior?
It accounts for variability in morphology and behavior between males and females
What is monogamy?
A mating system where one male pairs with one female, often when the female needs help or the male cannot cover more than one female.
What defines polyandry?
A mating system where one female has multiple male partners, typically when she requires significant help.
What is polygyny?
A mating system where one male mates with multiple females.
What influences group formation in females?
Resources and predator pressure.
What determines the number of males in a group?
The number of mates and reproductive synchrony of females.
What is reproductive synchrony?
The synchronization of estrous cycles among females.
How does resource availability affect reproductive synchrony?
Seasonal resources lead to synchronous reproduction, while abundant resources lead to asynchronous reproduction.
What is philopatry?
Staying in one’s natal group, which enhances environmental awareness and resource utilization.
What is a dominance hierarchy?
A social structure where individuals compete aggressively for resource access, prevalent in non-folivores.
How does social dominance rank correlate with reproductive success?
Higher social rank generally leads to increased reproductive success.
What are some benefits of high social rank for females?
- Earlier menarche
- Shorter inter-birth intervals
- Faster conception
- Higher infant birth weight
- Better infant survival
- Longer lifespan
What is sexual selection theory?
A theory that focuses on adaptations improving an organism’s chances of reproducing, sometimes at a survival cost.
What are intra-sexual selection adaptations?
Adaptations for outcompeting rival males, such as larger body size and fighting weapons.
What is sexual dimorphism?
The difference in size or appearance between males and females of the same species.
What is infanticide in the context of mating strategies?
When a male takes over a group and kills infants that are not his own to induce the mother to return to estrous.
What is pseudo-estrus behavior?
Behavior where females become sexually receptive during pregnancy to solicit mating from immigrant males.
What is optimal parenting?
Managing investment in offspring to maximize reproductive returns.
What are the differential costs and benefits of parenting for males and females?
- Length of investment
- Amount of investment
What is the reproductive insurance hypothesis?
The idea that parents lay multiple eggs to ensure survival under varying resource conditions.
What is inclusive fitness?
The total effect an individual has on spreading its genes, including its own offspring and that of relatives.
What is Hamilton’s rule?
Cooperation is favored by selection when the benefit to the recipient multiplied by the degree of relatedness exceeds the cost to the actor.
What is kin selection?
A type of natural selection that favors behaviors benefiting relatives, enhancing shared genetic success.
What is altruism?
Behavior that benefits another at a cost to oneself, often occurring among kin.
What is reciprocal altruism?
A form of altruism where the cost to one individual is outweighed by the future benefits received from the recipient.
What is social organization in primates?
The size, sexual composition, and spatiotemporal cohesion of a social unit.
What are the five main possibilities of grouping in primates?
Not specified in the provided text.
What is a mating unit?
Individuals that mate within a social unit.
True or False: All adults in a social unit get to mate.
False.
What are bachelor groups?
Groups formed by non-mating males.
Define social structure in primates.
How group members interact with each other, resulting in relationships within the social unit.
What does differentiated social relationships mean?
Individuals form specific relationships with different members of the group.
List the five main possibilities of primate group composition.
- Solitary (roving or dispersed polygyny)
- Pair living
- Multimale-unifemale (polyandry)
- Unimale-multifemale (polygyny or harems)
- Multimale-multifemale
What characterizes solitary primate groups?
Male territory includes the territory of many females, with females and offspring alone or males alone.
Which primates are known to be nocturnal and solitary?
Nocturnal strepsirrhines like lemurs and lorises.
What is pair living in primates?
A male and female with dependent offspring, typically territorial.
What is polyandry in primate social groups?
One female is paired with two or more males.
What is polygyny in primate social groups?
One male has several adult females and offspring.
Describe a multimale-multifemale group.
Typically very large groups with multiple mating, parental uncertainty, and combats infanticide.
What does dispersing sex refer to in primate groups?
One sex or both disperse from the natal group.
What is philopatric sex?
The sex that stays in the natal group and lives with their kin adults.
What does female bonded mean in primate social structure?
Males disperse while females remain in the natal group.
What is a dominance hierarchy?
A ranking system within a group that determines access to resources and mates.
What are kinship bonds?
Influence patterns of association, grooming, dominance, agonistic support, and mate choice.
Define male bonded social structure.
Females disperse while males associate more but do not form tight patrilines.
What characterizes bisexual dispersal groups?
Both sexes disperse, and no one lives with kin.
What does cohesion in primate groups refer to?
Close spatial proximity and coordination of activity.
What is fluid cohesion?
Spatially dispersed, subgroup formations, with little coordination of activity.
What is the fission-fusion society in chimpanzees?
Constant breaking into smaller groups then coming back together.
List factors that produce variability in primate social groups.
- Diet
- Food distribution
- Feeding competition
- Predation risk
- Infanticide risk
- Phylogeny
- Population density
