2.3 Reproductive animal strategies
Courtship
External fertilization vs internal fertilization
Ovipary,ovovivipary, and vivipary
Amniotic egg
Survivorship curves
Parental care
Reproduction
What is the main goal of each species? Produce the max number of surviving
offspring while using the least amount of
effort.
Courtship
Courtship The behaviour and/or signals that are
designed to attract another animal for mating
and breeding
Simple strategies Complex strategies
Chemical Unique to each species
Visual Females usually favours males:
Auditory stimuli Stronger
Larger
Examples: More energy in courtship
>moths produce pheromones
>most frogs sing(grunt/croak) =promises more bonding=more survival
>male birds sing species-specific songs then chance of offspring
uses colourful plumage
Example:
>blue cranes (series of calls, elaborate
dances)
>springbok have an annual rut(animals in
peak condition, show dominance by
protecting territory and attacking trees)
>timing is important
>some birds=courtship feeding
, External vs internal fertilisation
External fertilisation Takes place in water
Most aquatic vertebrates
Wasteful as huge number of eggs produced
Fertilisation is not certain
Maximises reproduction:
Huge numbers of egs and sperm relesed into
the water
Courtship rituals
Reproductive energy expenditure goes
almost totally to producing larger number of
eggs
Internal fertilisation Occurs in terrestrial vertebrates
Male gametes released diredtly into body of
female during mating= fertilises the eggs
inside of the body
Most birds and reptiles mate using cloaca
Males and females line up their cloacae for
transfer of sperm
The males of virtually all animals have a
penis, Process is called copulation
Maximises fertilisation:
More certain
Fewer gametes needed
Energy saved by producing fewer gametes
Ovipary, ovovivipary and vivipary
Terms for: The moment at which the furutre offspring
from a parent
ovipary Eggs develop outside of the parent
Majority of animals are oviparous
Egg yolk only food for developing embryos
Most fish and amphibians are oviparous
-eggs released and externally fertilised
Land animals (birds and most reptiles)
Courtship
External fertilization vs internal fertilization
Ovipary,ovovivipary, and vivipary
Amniotic egg
Survivorship curves
Parental care
Reproduction
What is the main goal of each species? Produce the max number of surviving
offspring while using the least amount of
effort.
Courtship
Courtship The behaviour and/or signals that are
designed to attract another animal for mating
and breeding
Simple strategies Complex strategies
Chemical Unique to each species
Visual Females usually favours males:
Auditory stimuli Stronger
Larger
Examples: More energy in courtship
>moths produce pheromones
>most frogs sing(grunt/croak) =promises more bonding=more survival
>male birds sing species-specific songs then chance of offspring
uses colourful plumage
Example:
>blue cranes (series of calls, elaborate
dances)
>springbok have an annual rut(animals in
peak condition, show dominance by
protecting territory and attacking trees)
>timing is important
>some birds=courtship feeding
, External vs internal fertilisation
External fertilisation Takes place in water
Most aquatic vertebrates
Wasteful as huge number of eggs produced
Fertilisation is not certain
Maximises reproduction:
Huge numbers of egs and sperm relesed into
the water
Courtship rituals
Reproductive energy expenditure goes
almost totally to producing larger number of
eggs
Internal fertilisation Occurs in terrestrial vertebrates
Male gametes released diredtly into body of
female during mating= fertilises the eggs
inside of the body
Most birds and reptiles mate using cloaca
Males and females line up their cloacae for
transfer of sperm
The males of virtually all animals have a
penis, Process is called copulation
Maximises fertilisation:
More certain
Fewer gametes needed
Energy saved by producing fewer gametes
Ovipary, ovovivipary and vivipary
Terms for: The moment at which the furutre offspring
from a parent
ovipary Eggs develop outside of the parent
Majority of animals are oviparous
Egg yolk only food for developing embryos
Most fish and amphibians are oviparous
-eggs released and externally fertilised
Land animals (birds and most reptiles)
