Mating systems Flashcards
1
Q
Anisogamy mating system
A
- Females produce few eggs (costly)
- Males produce many sperm (cheap)
- This difference is called Anisogamy
- Eggs are a limited source so males should compete
2
Q
Female breeding success
A
Limited by number of young raise
3
Q
Male breeding success
A
Limited by number of eggs fertilised
4
Q
Gestation and lactation
A
- Females constrained by costly lengthy development
- Males can move on with no time constraint, post copulation
5
Q
Carnivore parenting
A
- Prey must be hunted
- Paternital care needed
- Females solitary
- Males should stick around
6
Q
Herbivore parenting
A
- Abundent food
- No paternal care needed
- Females in groups
- Males should sleep around
7
Q
Monogamy
A
Exclusive mating. 1 male and 1 female
8
Q
Polygny
A
1 male, many females
9
Q
Polyandry
A
1 female, many males
10
Q
Polygny
A
- Dominant mammalian system 90%
- Takes different forms
- Commonly, males monopolise a groups of females (harem)
- Male competition leads to adaptions for fighting
- Males may try to attract many females as possible
- Females dispersed? Males may move around (rare)
11
Q
Leks
A
Places of land where groups of males display to females to mate
12
Q
Polyandry
A
- Rare
- May ensure fertilisation
- Reduce infanticide risk by males
- Common in polytomus (littering bearing species)
- Litters may consis of different patrinity
- Both sexes benefit
- Occurs in many primates and Semelparous animals
13
Q
Semelparous
A
Animals that only breed once in their lifetime
14
Q
Monogamy
A
- Rare (5%)
- Found in many orders
- Tends to occur in hunting species
- May occur when one male territory overlaps just one female’s
- May occur when females are at low density
15
Q
Group living may be promoted by
A
- Predation pressure
- Social foraging
- Thermoregulatory benefits
- Breeding constraints
16
Q
Solitary life
A
- Ancestral state
- Good option if resources easily/territory easily defended
- Found in most orders
17
Q
Semi-sociality
A
- Many mammals form temporary groups in some circumstances
- For protection, reproduction and warmth
18
Q
Sociality
A
- Many mammals live in groups year round
- Eat, don’t get eaten
- Direct social interaction but limited cooperation
- Independent breeding and caring for offspring
19
Q
Communal breeding
A
- Occurs in stable groups
- All females breed and care is shared
- Non-breeding females benefit by helping
- Rare in mammals
- Primates, rodents and carnivores
- Usually only one female breeds
- Reproductive suppression
20
Q
Eusociality
A
- Non-breeding females are sterile
- Very rare in mammals
