Chapter Twelve: Parental Care Flashcards
any investment that increases the chance of offspring surviving at the expense of other offspring
parental care/investment
benefits of parental investment
more offspring survive
costs of parental investment
predation while foraging (cost to self)
reveal location of nest to predators (cost to nest)
less time to mate again or produce eggs
need more food (energy cost)
___ and ___ are important factors in analyzing the costs and benefits of parental investment
how long you live and your potential for multiple “clutches”
few offspring lead to ___ parental investment because ___
high
you need those few offspring to survive
many offspring lead to ___ parental investment because ___
low
it’s not a big deal if some of them don’t survive
in birds, mates practice ____ and parental investment is ____
social monogamy
shared between the male and female until fledged
in fish, parental investment is ___
rare
if given, it is given by the male
in mammals, mates practice ___ and parental investment is ____
polygyny
mostly given by females, males give little help
species in which offspring don’t need much or any care when they are born
precocial species
in precocial species, males help ___ and compete for ___
least
multiple mates
species in which offspring need care at birth to survive
altricial species
in altricial species, males help ___ and sometimes males and females give ____
more
equal care
parental care that is given all by the mother is most common when ___
only one parent is required to stay and raise the young
two influences that cause parental care to be all by the mother
- anisogamy
- if paternity is unsure
how does anisogamy cause mother to give all the care
she has a higher parental investment from the beginning (has to make eggs while male only has to make sperm)
how does paternity being unsure cause mother to give all the care
benefits to female are greater than benefits for male (all the offspring are 100% hers, not 100% for male)
costs to females are lower than costs to males (he would have to give up extra matings to stay and help raise young)
when does the male give all the parental care
when the female is able to leave before the male
example of a species in which the male gives all the parental care
waterbug: female lays eggs on males back
male providing nourishment for the female at copulation is considered ___
parental investment
when does a parent need to identify their young
if the parent might encounter other young that are not their own
___ and ___ are the most common methods of identification
sound and smell
why do ring-billed gulls that nest on the beach need to identify their young but kittiwakes that nest on cliffs do not
ring-billed young can wander into another nest easily, if kittiwakes leave their nest they fall off the cliff
what are the costs of adopting genetic strangers
time/energy not for your own offspring
personal risk
what are the costs of not adopting genetic strangers
might miss out on taking care of your own
might be a strong fixed action pattern
the costs of adopting a genetic stranger depend on ___
the frequency it occurs
if strangers rarely wander into your nest, it pays to ___
if strangers frequently wander into your nest, it pays to ___
take care of all in the nest
pick out and only take care of your own
benefits of adopting a genetic stranger
male: increased mating if female choice is based on care
female: practice for when she has her own one day
benefits of not adopting a genetic stranger
more time and energy for your own offsprin
rearing young of different species
brood parasitism
five reasons a bird will accept a foreign egg into their nest
- rare event: chances of it happening are very low
- can’t expel the egg out of the nest
- no other nest sites to start over with
- mafia hypothesis: adults prey on nests that reject eggs
- supernormal stimulus: selection favors bigger or faster growing chicks of brood parasite species
the goal for parents and the goal for young are ___
opposite
the goal for parents is to ___
the goal for young is to ___
wean young so they can have more offspring
keep care as long as possible
killing your siblings
siblicide
siblicide often occurs in front of ___
parents
siblicide is related to ___
hatch timing
broods that hatch out at different times
asynchronous
an egret’s first egg gets more ___, making it ____; the ___ sibling will survive
testosterone
more aggressive
stronger
broods that hatch out all at the same time
synchronous
if food is low for a synchronous brood, chicks will ___ and there is less overall ___
fight for food
survivability
two hypothesis for why parents allow siblicide
- insurance against failure of the first born (second egg was merely a backup plan incase the first didn’t survive)
- environmental stability (if you have a bad year, this is a mechanism of making sure the most viable sibling survives instead of the least viable)
in the brown booby and the nasca booby, the older sibling ____
drives the younger sibling out of the nest where it will die of exposure and starvation
