week 5 + 6 - parental care

Question 1

parental care is

Answer 1

‘behaviour directed towards a reproductively immature individual that improves their chance of surviving to become reproductively mature’
- And able to look after them selves

Question 2

parental care
cost to parent

Answer 2

reduction in longevity and immune function and increases physical activity (food and predator defence)

Question 3

parental care
advantage

Answer 3

• Offspring survives and passes on genes to next generation
  o Long-term direct fitness (inclusive fitness)

Question 4

maximise reproductive success

Answer 4

• Females: mate and leave the male to take care of the young
• Males: mate with as many females as possible and leave females to take care of young

Question 5

maternal care

Answer 5

• E.g. most animals
• Large investment
• Only the mother

E.g. orangutans
- longest inter-birth interval of any mammal
o time of parental care
- long period of development, learning etc.
- rarely more than one infant at a time in the wild
- One infant every 7-9 years
- Rarely have more than one infant at a time
- Because lots of learning needs to happen in order for offspring to survive

Question 6

paternal care

Answer 6

• E.g. seahorse, stickleback fish, only 5-10% of mammals
• Only father
• Not common

Lots of offspring
Male seahorse does a lot (expends a lot of energy)
Male incubates the eggs
Females eggs
Females still invest more in reproduction
* More energy to create eggs

If the male incubates the eggs overall success rate for both of them is greater (hatch inside, he feeds then for a short amount of time then expends them)

Shorter inter-birth interval (female doesn’t incubate so eggs ready sooner after fertilisation/male expending the eggs)

Question 7

biparental care

Answer 7

• E.g. penguins, California mice, marmosets, 90% of birds
• Male care: increases survival of offspring to such an extent that caring outweighs the cost of any lost mating opportunites
• More common in birds, less so in mammals, why?
  o In birds both sexes can take equal roles in feeding
• E.g. California mouse
• Lone females or lone males aren’t successful at raising young, or chances of survival are much reduced

Question 8

alloparental care

Answer 8

• E.g. African wild gods, meerkats, some primates
• Not just mother and father

e.g. meerkats
- cooperative breeders
o dominant breeding pairs that have litters
- sub-adults (kin) stay with the group and help raise next generation or two before leaving: increases survival
o also kin has practice helping raise young
- extreme examples = eusocial species
o Abandon any hope of breeding themselves

Question 9

why stay with the group
(indirect fitness)

Answer 9

• Helping kin
• Gain experience
  o So offspring would be more likely survive
• Access to resources
• Nowhere else to go
  o Ecological constraints hypothesis
  o No other territory or space to move into. So better to help kin (indirect fitness) then not do anything at all

e.g. cooperatively breeding cichlid fish are more likely to stay with the group and within protective shelters when predation pressure is high