lecture 5 Flashcards
Behavioural ecology
the study of the way in which primate adapt behaviourally to the environment
Disadvantanges to studying primates in captivity
- environments can be manipulated
- regular provisioning (feeding) can cause them to forget their natural foraging patterns
- captivity can alter their activity patterns, mating patterns, and increase levels of aggression
- can be more prone to stress which causes abnormal behavior
- lack of seasonal changes can effect reproductive patterns which will effect the birth rate
- can carry pathogens that are harmful to humans
habituated
accustomed to the presence of humans
social living
predators and resources - main help and focus
- allows for lots of mating partners, increase in reproductive fitness
- protection from predators as well as other primates in the group
- helps caring for offspring
- transmission of behaviour from one member to another
larger groups
more competition
more predators
more likely to find food in a bigger group
small groups
usually found when resources are dispersed
social brain hypothesis
cognitive demands of living in complex social groups explain why primates have unusually large brains for their bodies, particularly the neocortex
negative aspects to social living
- spread disease
- competition for food and mating
- higher stress, which gives lower birth rate and higher aggression
monogamous groups
1 male and 1 female and their offspring
- little sexual dimorphism because there is less competition
- males invest more energy into offspring
- gibbons and siamangs
single-male/ multi-female
polygynous
one male mates with more than female
howler monkeys
Polyandry
1 female with more than one male
males take care of offspring
marmosets and tamarins
Multi-male/multi-female
found in areas where predation is high
high levels of sexual dimorphism
fission-fusion groups
social group who’s members change as sub-unit split apart (fission) and then join again later (fusion)
fluid membership
solidarity
being on your own, forgoing on your own and only interacting occasionally
oranugutans
philopatric
females typically
remain in birth group
males usually get kicked out so there is no interbreeding
Matrilineal
descent is traced through the female line
Dominance Hierarchies
social structures in which males and females hold positions of rank determined through competition or inheritance
- found in single-male/multi-female and multi-male/multi-female
Males attain rank through
aggression, physical strength, ability to mobilize and support their alliances
Female dominance
usually seen more stable
male dominance
rapidly changing based on body size, kinship, and other factors
zoopharmacognosy
self medication by animals with plants, soils, and other natural substances
Agonistic behaviour
threatening behaviours that are directed toward an opponent or adversary
- can be between same sex or different sex
- frequency of behaviours depend on: food resources, mating partners, and space (territory)
- can be facial expressions, gestures (baring canine teeth), or fighting
- males are face to face while females are prolonged
- patterns of injury vary by sex, rank, and age.
Affiliative behaviours
grooming and alliances
Altruistic behaviours that benefits other members of a group but it is either of no benefit to the individual engaged in it or harmful to that individual
- grooming: removes ectoparasites (parasites that live outside of the body, like on fur), reduces stress, reinforces social bonds, carrying favours such as food, sex, and protection, gaining access to infants
- occurs between lower rank and higher rank individuals, males and females, related and unrelated, and parents and their offspring
larger groups = more time spent grooming, but number of grooming partners decrease so there are stronger alliances
Alliances
Kin selection: tendency of primates to direct beneficial behaviour towards relatives living in the same group
- fosters alliances and maintains social bones
- alliances are formed for access to food resources and mating partners as well as gaining protection from predators
Consortship
temporary alliances of males and females for the purpose of mating and reproduction.
Can be forced onto a female by males
Reconciliation
making peace after an altercation
Preceptive Behaviours
actions to initial sexual interaction: facial gestures, limb and body gestures, movements and sounds
Females swell and turn pink when they are fertile
Females secret aliphatic acids that releases and oder to say she’s ovulating
Mate guarding
dominant male restricting sexual access to reproductive female
Sexual Selection
males of some species adapt behaviours and morphologies that may not appear to be adaptive in terms of natural selection
traits that enhance reproductive opportunities as a result of successful competition with other males
- males tend to be larger with flashy adornment
- two sexes employ different strategies to solicit mates - distinct competition and male choice
Parental Investment
appointment of resources (time, food, protection, caregiving) by males and females into the success of rearing of offspring
Female Strategies for mating
choose more dominant males with the assumption that they will have high quality offspring
choose males with more affiliative behaviours (protection and care)
May sink her reproductive cycle with other females because single males can’t mate with all females
May compete with other females
Mate more than once to get extra help from all males that she mated with, as they won’t know if the offspring is theirs
May sync her reproductive cycle with seasons for resource availability
If births are synced there is less chance of infanticide/young death because there will be so many infants
Mate with unfamiliar mates to avoid interbreeding and maximize partners
Male Strategies for Mating
sperm competition: if females mate numerous times with multiple males, males who deposit the largest volume of sperm of higher quality should be the one impregnating the female
formation of copulatory plugs, bigger testes, bigger penis will have better sperm
- being bigger in size in competition
- infanticide - killing of infants so females can stop lactation and start their reproductive cycle again and become fertile quicker so the male can mate. - lower inter-birthing
Language and Communication
- visual, auditory, olfactory, and tactile
Visual forms: include facial expressions, gestures, postures, eyelid flickering, lip smacking, tongue flicking, exposing canid teeth
pantomime: gesture that expresses meaning
Auditory: alarm calls, howling, long songs, vocal calls
Olfactory: scent marking for territory, urine washing, stink fighting - ring tailed monkeys
Tactile: touch - grooming, touching, embracing, hand clasping.
Insectivores
- smallest 1kg
- smaller teeth, big molars with sharp cusps - this is to break tough exoskeletons of insects
- least complex digestive system (short simple gut)
Gumnivores
- smallest 1kg
- long cecum and a dental comb
Herbivores (Folivores)
- largest can go up to 100kg
- leaves, seeds, and herbs
- very large intestine, large cecum, and large stomach - this is because cellulose found in leaves is very hard to break down
- small incisors, well developed molar sheering crests
- honing complex: diastema between canine and premolars that sharpens the canines to break apart cellulose
- ruminant, chew - digest - regurgitate - digest again
Fruitivores
- can be on the smaller side if they also eat insect (1-10kg)
- can be on the larger side if they also eat leaves (1-50kg)
- long small intestine
- large broad incisors, low rounded molar cusps
- soft diet
Territoriality
Cost: time, effort, and risk
- a lot of investment, not doing things like reproduction, grooming mates, and getting resources
- chimps are territorial as well as gibbons
Benefit: if you can keep other members out you have complete access to resources
Predation
usual predators: crowned hawk eagle, leopards, other primates
- African primates: predators are forest dwellers - leapords
- South America: large cats so there are 0 terrestrial primates
- SEAsia: terrestrial primates - predators are other primates and maybe crowned hawk eagle
Mobile distributions of primates
Crowned hawk eagle: 70-80% small primates (constrained by size)
- mainly go after potto, mangeby, and guenon monkeys
Leopards: can’t climb trees very well so they go after terrestrial primates, chimps, colobus.
Social behaviour
group behaviour is very important, you have individuals looking out for you
3Ds: Detection, Deterrence, Dilution
detection: more eyes to see predators in the group
deterrence: howling or other alarm calls to let group know predators are near
Dilution: the more in the group the less likely you are to get caught
Joint defence of food resources is profitable when:
- Food resources are relatively available
- food resources are clumped in time and space
- There is enough food in the patch that meets the needs of several individuals in the group
Biological constraints to mammalian reproductive systems
- commits females to pregnancy and a long period of lactation if offspring is to survive.
- costly it requires more resources
- need 10% more dietary intake then when not pregnant
- need 25% more dietary intake during lactation
- must eat more, rest more, and invest time in offspring
- gestation period is longer in primates, and they take longer to mature
- this causes some primates to only have 1 offspring but it is up to the mother and alloparents
- infants are completely dependent upon mother (touching and direct contact) for the first year and a half and then after is a long period of allocare
Female competition for mates
dominance hierarchies for access to food, higher ranking females get more food (30%) and security
- this is usually linked with longer life expectancy and reproductive success
- low rank females will typically eat away from high rank females so that they don’t get harassed
- this is high risk behavior because there is no protection from group and you could be crossing another groups territory
- advantages to this is forming allies with other females form other groups for protection and possible take over, and can for allies with dominant males of other groups
- form friendships for protection but grooming others and spending time together
Grooming and Friendship (Allies)
- taking parasite off each other, sit with each other, eat with each other
allows for greater social bond, protection, usually have higher survival rate if engaging in this type of behaviour
Male reproductive strategies
sexual dimorphism is high in males that have to compete (single male, multi male groups)
- larger, more colourful, have particular display patterns that result from competition for access to mates
- sexual selection is stronger in comparison to natural selection for mammalian animals
- males can have more offspring than a female can have because they do not have to invest in offspring
Intra-sexual selection
members of same sex competing
between males and other males
success = reproductive access
inter-sexual selection
members of opposite sex
males trying to get females to pick them, female’s choice
Pair-bonded groups
does not mean monogamy
- least sexual dimorphism in this group
- high levels of parental investment, mate guarding and offspring care
breeding cooperative - sometimes found in pair bonding
NON-pair bonding
males get kicked out of birth groups typically by other males or even the females, this prevents interbreeding
- in order to increase survival of males that get kicked out they must
1) scope out other groups before they get kicked out
2) transfer into group that have familiar males from birth group
3) leaving with peers or joining with all male-bands
single-male/multi-female
highest degree of sexual dimorphism
- competition is high as the dominant male has to keep out all other males as they attempt to do a take over
alpha males cannot block off all females of the group, sometimes outsiders can get access
- need to be strong in order to protect territory, females, and food
Multi-male/multi-female
High degree of sexual dimorphism
- males hover over peripheral of group waiting to do a take over
- could be a male that just got kicked out and formed alliances to come back
- females choose in this type of group, so males must outcompete each other to impress the females, this is done through challenges, chases, interrupting copulation, and fighting
- dominance hierarchies for males in the are for reproductive access rather than good
- mate guard when females are fertile so that they guarantee it is their offspring
Infanticide
kill offspring that are not their own so that they females ends lactation and start their reproductive cycle again
- gorillas, chimps, baboons, 30% of infant mortality
females strategy to prevent: syncing birthing, and mating with many males so they don’t know if they offspring is theirs or not, more hesitant to kill
Polyandry
Females mates with many males (strategy for infanticide) and males will all invest in parental care because they want their potential offspring to survive
