Chapter Eleven: Mating Systems Flashcards
mating systems represent males and females trying to ___
maximize their parental investment
males pay a ___, females pay a ___
mating cost
fertility cost
one male mating with one female for a reproductive cycle or for life
monogamy
more than one mate at a time
polygamy
one male mates with multiple females
polygyny
one female mates with multiple males
polyandry
multiple mates for everyone, “explosive breeding event”
promiscuity
what is the most common mating system
polygyny
three influences on mating systems
- ecological factors
- parental care or other assistance requirement
- female-enforced systems
open areas are more likely to have ____ mating system
polygamy
dense forests are more likely to have ____ mating system
monogamy
if both parents are needed to care for the young, ___ would be beneficial
monogamy
in a female-enforced system, the female forces ___ on male
monogamy
monogamy is ___, especially in mammals
rare
why is monogamy rare in mammals
female has to stay around to nurse the offspring, she physically can’t leave them, but the male can easily leave and mate with someone else
5 cases in which monogamy is beneficial
- mate assistance theory
- if the female remains receptive to other mates
- female enforced monogamy
- synchronized breeding
- when it is difficult to find another mate
the mate assistance theory states that ____
monogamy is beneficial because the raising the young requires assistance, female can’t do it on her own
seahorses are monogamous for life, the males ___ while the female ____
care for young
recovers quickly and can have more babies sooner
the hornbill nests in tree cavities that they close off, have to be monogamous because ____
male has to bring the enclosed female meals
burying beetle males try to attract other females to a nest, but the original female will _____
this is an example of ____
knock him off his perch
female-enforced monogamy
when all females breed within a few days of each other
synchronized breeding
synchronized breed occurs in ___ and leads to ____
large communal groups
monogamy
why does synchronized breeding lead to monogamy
by the time the male has mated with one female, all the other females have also mated so there are no more available females
eagles have a very low ___, so monogamy makes sense
population density
what does extra pair copulations mean
cheating on your monogamous partner
social monogamy is not always _____
genetic monogamy
benefit of extra pair copulations for males
more offspring
3 hypothesis of the genetic benefit of extra pair copulations for females
- fertility insurance hypothesis
- good genes hypothesis
- genetic compatibility hypothesis
what does the fertility insurance hypothesis state
mating with several males reduces the risk that some of her eggs will remain unfertilized
what does the good genes hypothesis state
her social partner is of less genetic quality than other males, so she will mate with other males to improve offspring viability
what does the genetic compatibility hypothesis state
mating with several males increases the genetic variety of the sperm available to the female, so it increases the chance that some sperm will have DNA that is an especially good match with the DNA of her eggs
4 hypothesis of the material benefit of extra pair copulations for females
- more resource hypothesis
- more care hypothesis
- better protection hypothesis
- infanticide reduction hypothesis
polygyny is related to the ____
distribution of females
males fight with other males for females
female defense polygyny
female defense polygyny is seen where ____
females congregate for reasons unrelated to reproduction
male defends territories and female chooses a male based on the quality of his territory
resource defense polygyny
the polygyny threshold model states that there is a resource level where its better to be a ____ than a ____
second female in a good territory
first female in a bad territory
simply finding a female first, not territorial, no dominance hierarchy
scramble-competition polygyny
in scramble-competition polygyny, the males with the best ____ mate the most
tracking skills
males guard a symbolic territory or display that attracts females
lek polygyny
a small, symbolic territory that attracts females for mating
lek
in lek polygyny, ___ do the majority of the mating
a few of the best males
three hypothesis for the benefits of leks to males
- hotspot hypothesis
- hotshot hypothesis
- female preference hypothesis
the hotspot hypothesis states that
the lek is a place where females frequent
the hotshot hypothesis states that
inferior males will be near the superior male and get the overflow copulations
the female preference hypothesis states that
males assemble because females prefer sites with many males rather than just a few
polyandry is ___
rare
polyandry occurs when there are ___
more males breeding than females
two selective pressures of polyandry
nest sites are limited
potential for heavy losses of eggs or clutch size limitations
