10: mating systems Flashcards
what 4 things are included in a mating system classification?
- copulation behaviour
- social organisation
- parental care system
- competition for mates
list the 4 mating systems
- monogamy
- polygyny
- polyandry
- polygynandry
what do social mating systems not always reflect and give an example
the genetic mating system
extra pair paternity in birds
what is monogamy and give 4 examples and which group are mainly monogamous
1 male and 1 female birds - swan - clownfish - fulmar - splendid fairy wren
roughly what % of birds are socially monogamous and what % are also genetically monogamous?
90%
<25%
- what is polygyny
- what group is it mostly
- what are the 2 types and an example for each
- 1 male and >1 female
- mammals
- simultaneous: red winged blackbird
successive/sequential: orangutan
- what is polyandry
- what are the 2 types and an example for each
- what can often happen in this mating system?
- 1 female and >1 male
- simultaneous: painted snipe
successive/sequential: spotted sandpiper - sex role reversal
- what is polygynandry
- what groups are mainly included
- give 2 examples
- > 1 female and >1 male
- reptiles, fish, amphibians
- guppy and foam nest tree frog
mating systems often vary within a species, list 3 examples
- extra pair paternity in monogamous species
- dunnocks
- humans
what mating systems do dunnocks engage in and in what proportions?
- 1/3 monogamy
- 1/4 polygyny
- 40-50% polyandry or polygynandry
what is the reproductive potential for males and females like and what they are limited by
males > females
- males limited by access to females
- females limited by access to resources
what should males do to maximise their fitness?
directly monopolise lots of females or monopolise resources she needs for survival and reproduction
what determines the mating system?
female and male dispersion
what is the general model?
what does It predict?
ecology/resource distribution > female dispersion > male dispersion
- predicts that mating systems should reflect female dispersion and resource distribution
what is resource defence polygyny and an example?
- males defend key resources wanted by females
tent making bats- males construct and defend roosting tents that house harems of females with 1M: 1-37F
in mammals male parental care is rare so what does female monopolisation by males and mating system depend on?
- female group size
- female range size for travel
in Clutton Brock 1989 study what was discovered for when females are solitary and the range is defendable? (3)
- 60% mammals
- small range: polygyny, voles and otters
- large range: monogamy, gibbon
in Clutton Brock 1989 study what was discovered for when females are solitary and the range is not defendable? (3)
- scramble competition
- polygyny
- orangutan cant defend the widely distributed rainforest patches
in Clutton Brock 1989 study what was discovered for when females are social and the range is defendable? (2)
- small group: uni male polygyny, colobus
- large group: multi male polygyny, lion
in Clutton Brock 1989 study what was discovered for when females are social and the range is large and not defendable? (3)
- large unstable groups
- males may aggregate in leks when high competition for females
- Uganda kob
- Topi
list the two example experiments to answer the question: do resources determine female dispersion and in turn male dispersion?
- blue headed wrasse
- grey sided vole
blue headed wrasse all start off as female and become males at a certain size- what is the difference between the males and females? - 2 for each
females - forage over large overlapping ranges - spawn daily at favoured sites males - cant defend females - compete for and defend spawning sites on reefs
what was warner 1990 experiment on blue headed wrasse (5)
- removed males and replaced with new ones
- when males removed 22/24 sites still used and no new sites, would follow what previous males did
- removed females and replaced with new ones
- when females removed 11 sites lost and 10 new spawning sites found
- females determine the site of spawning and males compete to defend those sites
what was experiment 1 for the grey sided vole? (3)
- small patches rich with food
- food distribution determines female distribution
- males also followed
what was experiment 2 for the grey sided vole? (3)
- captive females and radio tracked males
- males would collapse their range around the females
- female dispersion determines male dispersion
what was experiment 3 for the grey sided vole? (3)
- captive males and radio tracked females
- no effect of male dispersion on female dispersion
the reproductive potential of males is not always realised so what does this mean for the mating systems and their reproductive success?
sexual conflict over them
more variation
how can females maximise their reproductive success?
monopolise parental care from males
where is sexual conflict over mating systems common?
in birds
what type of mating system does the male and female prefer?
male: polygyny
female: polyandry so can get more or better resources such as parental care
in many species why does monogamy often occur?(3)
- at a compromise between conflicting interests of the sexes
- males may be unable to defend more than 1 female at a time
- female may force monogamy upon male
what is the yellow bellied marmot example for sexual conflict over mating systems? (2)
- females raise more offspring in smaller groups and get more parental care
- male overall gains more offspring in a large harem
what is the female enforced monogamy in burying beetle example for sexual conflict over mating systems? (3)
- female and male make a nest with a corpse and care for offspring
- males attempt to attract extra females using pheromones
- females try to prevent males form doing so
give 5 points summarising mating systems
- very variable
- potential reproductive rate drives variation
- ecological factors set the scene for mating system evolution
- experiments support general model
- sexual conflict plays a key role in mating system evolution
