4 - Mating systems: mammals Flashcards
List the four most prominent forms of mating systems in mammals
- Monogamy
Polygamy (polygyny and polyandry)
- Promiscuity
Describe mammalian mating systems
Mating system depends on female ranging behaviour and economics of defense
- Mainly maternal care
- Mainly polygynous
What determines if females are solitary or dispersive? (3)
Males? (2)
What is the consequence of this?
Female dispersion
- Resource dispersion
- Predation
- Benefits and costs of social living
Male dispersion
- Female dispersion (males go where the females go)
- Resource dispersion
Mammalian mating system depends on: female ranging behaviour.
Effects economics of defence for males (how males compete for mates)
Females produce milk and give live birth, bias towards polygyny because females dependent on resources and males dependent on finding mates.
What is range defence polygyny?
Male defence of females within a certain range.
Can include more than 1 male.
What is monogamy?
Mating with one male per breeding season
Can mate with another male in another season
What are two types of polygyny?
- Female defence polygyny (aka harem defence)
- Resource defence polygyny (defending rich territory)
These are often hard to distinguish
What is the mammalian mating system when females are on their own (solitary) and don’t wander (they’re defensible)?
Males will defend home range of female.
Range defence monogamy
A case where you can get male parental care in mammals and monogamy (one of the few cases for monogamy in mammals)
What is the mammalian mating system when females are on their own (solitary) but they wander over a huge area (not defensible)?
There’s no way that the male can defend the area, you get roving males
Males wander over the large area and mate with females when they are oestrous (eg. polar bears)
If a mammalian female’s home range size is large (usually because food is scarce), then the male does what?
How is this different with high food?
Low food: Defends that female in that home range and get a monogamous mating system.
High food: You get polygyny, as male can defend the same area space, but can fit more females into the territory
What is the mammalian mating system when females are in social groups in a defensible home range?
Males defend that home range
range defence polygyny
- More than one male can participate in this mating system
- You can observe infanticide in this system, where new male kids young kids on territory
What is the mammalian mating system when females are in social groups that wander far distances (not defensible) in seasonal patterns?
Males try to capitalize on predictability of female movement (eg. coming to particular water hole)
- Males can depend part of the range where females funnel through
- This can change depending on the seasons (eg. males can move to make parts of migration routes their territory)
- This is also known as leks, as multiple females are coming to single male’s territories
What is the mammalian mating system when females are in social groups and wandering over a huge area, but not wandering in seasonal patterns (not predictable)?
The males have permanent defence of the female group, they stick with them.
Lots of energy expended
How does the mating success vary for different males in leks?
Certain males get a much bigger share of reproduction.
- Intense intrasexual and intersexual sexual selection
How do leks work for most mammals? (4 different hypotheses)
The hotspot hypothesis
- Males occupy hotspots for attracting females
The hotshot hypothesis
- A male is attracting females, other males go to take advantage
Stimulus pooling
- All males joining together to give strong signal for females (eg. spring fever)
Facilitating mate choice
- Females going to places where they can choose (eg. going from one male to another, driving males together)
