Phenotypic gambit
Ignore genetics and focus on the fitness of phenotypes
Useful way to test evolutionary hypotheses
Focus on reproductive success
Behavioural ecology
The study of natural selection as applied to behaviour
Estrus
The period around ovulation where the female is able to conceive
Concealed ovulation
Hiding that they are in ovulation
Ex. Humans
Use other cues like scent and proceptive behaviour
Reproductive success
An individual’s genetic contribution to future generation
Currency used to measure success
The number of offspring an individual produces
Sexual selection
Selection in relation to sex to natural selection
Intrasexual selection
Competition for mates
Intrasexual selection and precopulatory
Monopolize a single female
Intrasexual selection and postcopulatory
Multiple female matings
Intersexual selection
Choice of mates
Intersexual selection and precopulatory
Males displaying
Intersexual selection and postcopulatory
Female prevents sperm from contacting eggs directly
Sexual conflict and precopulatory
Intimidation and harassment
Sexual conflict and postcopulatory
Traumatic insemination
Mate guarding
The guarding a females that the male wants to mate with
Bateman Principle
Males benefit more by mating with multiple females while females only need one mating partner
Females produce a few highly nutritious gametes while pales produce a lot of smaller ones
Darwinian Sexual Selection
Females as the ecological sex and males as the mate getting sex
Ecological sex
Concern they have the resources that the fetus survives
Mate getting sex
Getting more mating opportunities
Sexual selection theory
Male primates are usually bigger than females
Better at fighting, more favoured, monopolize better, have more offsping
Polygynous
Many females per male
Males are usually bigger (more competitive)
Ex. geladas
Monogamous
One female per male
Body size dimorphism
Male body mass/female body mass
Canine size dimorphism
Male canine height/female canine height
Operational sex ratio
OSR
Number of sexually active males/Number of sexually receptive females
Polygynous breeding system (male traits)
Bigger than females
Bigger canines
Impressive looks
Aggression
Hormones
LRS
Lifetime reproductive success
Scramble competition
Conceptive efficiency
Faster sperm, plugs, etc.
4 step mammalian socioecological model
Predation + competition for food = FF relationships
Competition for mates = MM relationships
Infanticide, herding, harassment = Male coercive strategies
Female choice, alliance, pair bonding = Female counter strategies
Langurs
Colobine monkeys from Asia
Eat leaves, one male multiple females, natal females in the same group, society is calm until new male takes over
Infanticide
Killing of infants
Results in rapid inter birth interval (IBI)
Was assumed to be pathlogical
Case of selfish behaviour by natural selection
widespread in animals
Prevasive force affecting social behaviour/promoting groups
IBI
Inter birth interval
Pathology
Mental abnormality
Infanticide tendency
Is only seen with definite non offspring
Bruce effect in Wilde geladas
Females will unconsciously terminate their pregnancy when their is a case of infanticide due to hormonal cascade