Final Flashcards
Life expectancy
- an average computed over all people including those who die shortly after birth, those who die in early adulthood in childbirth or in wars, and those who live unimpeded until old age
- an average that tells us the number of years that someone is expected to live from a specific starting point
Lifespan
An individual specific concept; maximum lifespan is an upper bound rather than an average
- the max # years individual is expected to live; calculated by looking at the maximum # years someone from the same dataset lived
Primate lifespans and body size
- larger bodies animals live longer
Male vs female lifespans
- female primates live longer than males
- males tend to have riskier lives: dispersal, higher intra- sexual competition, more physical fighting
Altricial
- underdeveloped
- primate infant brains are fairly underdeveloped at birth
Precocial
- well developed
- active or physically mobile at birth
Strepsirhines less or more altricial
- less altricial
More altricial
- happlorrhines
- within primates precocial offspring is considered the primitive trait
Mothers are parkers
- some lemurs and lorises
- short lactation with high- fat milk
- post partum mating
- no infanticde
Mothers are carriers
- most haplorrhines
- long lactation with low-fat milk
- no post-party’s mating
- infanticide occurs
Socialization
- modification or behaviour through observation of and interaction with others in the social group
Why is socialization important in primates?
- large brains relative to body size and heavy reliance upon learning for survival lead to slow maturation and lengthy period of dependence
Infant socializing agents
- mothers
- adult males
- handlers
- peers (other infants)
Mother- infant relationship
- the first social relationship the infant will form
- very strong
- mothers actively and passively shape the infants social environment
Variability in maternal care
- Age of mother
- Parity of mother (experience)
- Rank of mother
- Temperament of mother
- Temperament of infant
- Species differences
- Sex of infant
- Food availability
Why do males interact with infants?
- sexual selection and female choice
- parental investment
- paternity certainty
- kin selection
- siblings, other maternal kin
Indirect paternal care
- tolerance, detection, and defence against predators, resource defence for group
Direct parental care
- direct male care is favoured when infants require a high level of investment (eg callitrichids)
- male care is predicted to be higher when paternity certainty is higher (monogamy)
5 categories of adult male- infant interactions/ relationships
- Intensive care taking
- Affiliation
- Occasional affiliation
- Tolerance
- Use and abuse
Intensive caring
- males spend large portion of their day in infant care taking
- parental firings shared
- male care ends when infant capable of independent movement
- most common in callitrichids
Prolactin
Females: prolactin stimulates the mammary glands of mothers to make and secrete milk
- elevated levels of prolactin also found in males who participate in paternal care
- prolactin comes before caregiving
Allocare/ infant handling
- any behaviour in which any individual besides the mother touches, inspects, grooms, holds, babysits, plays with, carries, or nurses infant
- key: TOUCH
- the amount of handling an infant received is primarily regulated by the amount of maternal tolerance
- Triadic: Mom, infant, handled
Maternal tolerance
- mom’s willingness to give up baby to handler
Why does infant handling occur?
- Learning to mother hypothesis (benefits handler, individual selection, some support)
- Mother relief hypothesis (benefits mother, kin selection and inclusive fitness, not supported)
- Promotes development (benefits infant- not yet supported at intraspecific level)
Who handles the most?
- very young infants handled the most
- nulliaprous females handle the most
- despotic primates have less handling overall and more negative handling
- egalitarian primates have more handling overall
Colobines and handling
- colobine mothers (egalitarian) are more permissive with their infants than cercopithecine mothers (despotic)
- colobine infants are handled earlier, longer, and by more individuals
Aunting to death
- the killing of infants by inexperienced or violent handlers; occurs when infants starve because of lost access to milk or infants die due to neglect
- proximate: inexperienced females don’t know how to take care of infant
- ultimate: trying to reduce completion
Peers and play
- young primates interact with age mates
- first experience interacting with non- relatives
- first opportunity to learn social skills outside of kinship context
Characteristics of play
- exaggerated, repeated, restrained, often accompanied by a “play face”, quiet
- can be solitary, solitary with objects, or social
Function of play
- practice for adults- physical and social
- teaching/ learning
- bonding
- skill acquisition/ demonstration
- stress relief
- immune exposure
- increase enjoyment of mundane
Who can play with depends on group composition and dispersal
MM-MF bonded: play with kin and friends
Monogamous: play with neighbours, sobs, parents; solitary play more common
Infant mortality
- extrinsic mortality risks are highest during infancy
- main causes: disease, stochastic events, malnutrition, infanticide
Infanticide
- females with long lactation periods undergo postpartum amnorrhea and no post partum mating occurs
- loss of infant = female resumes estrus sooner
Parent- offspring conflict: weaning
- a major time conflict
- offspring demand more from their mothers than they are willing to give
- mother stops investing in offspring sooner than it wants
Juvenile
- period from weaning to sexual maturity
- unlike infants, likely to survive death of mother
2 strategies to surviving being a juvenile
- Minimize time spent as a juvenile (strepsirhines)
2. Grow slowly (haplorhines)
Growing slowly benefits
Niche separation: small- body allows feeing on terminal branches
Growing slowly costs
1) increased vulnerability to predators
2) feeding efficiency and diet is less than adults
Puberty
Hypothalamus–> secretes hormones–> activates pituitary gland –> affects gonads
- more gradual for males than females
- dispersal usually takes place before puberty or before sexual activity
- dispersing sex high mortality
- secondary sex characteristics appear
Adulthood
- more or less continuos from puberty to death
- no major stages or categories within the adult life course
- no distinct role or behaviour for old NHPs as there is for humans
Why no distinct social role or behaviour for old NHPs
- division of labour (humans more dependent, change ability produce change social role not death)
- ## awareness of mortality (not aware NHP)Menopause (reproduction cessation but other organs healthy)
