Birds and mating systems
- Created by: Louis James
- Created on: 08-01-13 18:31
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Biological diverstiy - birds+mating systems
- investment - parenting
- crocodiles nest guard+guard young
- reducing weight - eggs - flight = limits egg size
- young = altricial - born blind, featherless+helpness
- early stage - development - hatch investment - parents = nest defence, incubation eggs, feeding
- survival - young requires biparental input
- stable environments - guaranteed food supply+few predators = smaller clutch size
- David Lack suggests average clutch size reflects number lead - most surviving offspring (natural selection)
- evidence - birds decide clutch size (some extent) - phenotypic plasticity
- r type strategy = lots eggs - less time - each egg
- k type strategy = few eggs - more time - each egg
- more organism invests resources - reproduction - less resources - own survival
- lack clutch size not generally seen - clutch size = below optimum - offspring survival - reflects adult mortality
- female invests more - beginning = more costly produce egg than sperm
- amount energy needed - raising young promotes monogamy
- more - 90% bird species = monogamous
- some species, both genders - brooding patches
- birds appeared - monogamy - not always. Dunnocks - various mating strategies
- social mating system. genetic mating system
- extrapair fertilisation/copulations = common - genetic testing…
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