REPRODUCTIVE ANIMAL STRATEGIES
Unique reproductive strategies have developed that will ensure successful
reproduction in different environments – this allows species to breed successfully &
survive to reproductive age
Goal of every species: produce the max. number of surviving offspring while using
the least amount of energy
A) COURTSHIP Behaviour/signals that are designed to attract another animal to
mate
Courtship strategies ensure that that males and females find suitable mates
(i.e. the strongest male)
Sexual behaviour in courtship is timed so that both animals are ready to mate
Energy expenditure is usually by the male – female conserves her energy
Springbok they have an annual rut (period of sexual excitement
Mothers are in good condition
Environmental conditions are in a suitable state to support the
offspring in terms of food availability
Males establish territories (10 – 70 hectares) by urinating and
dropping dung
Defend territories with loud grunts
Attack vegetation with their horns
Fight w/ their horns for access to females un neighbouring
territories
Females roam territories for larger males, more elaborate
physical features, display more energy in courtship activity
than other males
These features help the female choose the best male which
will give the offspring the best chance of survival
B) EXTERNAL VERTILISATION takes place in water
Fertilisation in bass & other aquatic animals is external
Female releases many unfertilised eggs into the water, at the same time- the
male also releases sperm which fertilises some of the eggs
Because fertilisation in water is not certain – bass must release huge numbers
of sperm – increases probability of fertilisation
Large number of fertilised eggs – enough offspring will survive and grow into
adults
Wasteful as huge numbers of eggs are released
Most eggs are eaten by other animals
Fertilisation is not certain
Reproductive energy – all goes into producing the huge number of eggs
C) INTERNAL FERTILISATION occurs in terrestrial vertebrates (reptiles, birds,
mammals)
Fertilisation is more certain as the sperm fertilise the egg inside the female
during mating
Unique reproductive strategies have developed that will ensure successful
reproduction in different environments – this allows species to breed successfully &
survive to reproductive age
Goal of every species: produce the max. number of surviving offspring while using
the least amount of energy
A) COURTSHIP Behaviour/signals that are designed to attract another animal to
mate
Courtship strategies ensure that that males and females find suitable mates
(i.e. the strongest male)
Sexual behaviour in courtship is timed so that both animals are ready to mate
Energy expenditure is usually by the male – female conserves her energy
Springbok they have an annual rut (period of sexual excitement
Mothers are in good condition
Environmental conditions are in a suitable state to support the
offspring in terms of food availability
Males establish territories (10 – 70 hectares) by urinating and
dropping dung
Defend territories with loud grunts
Attack vegetation with their horns
Fight w/ their horns for access to females un neighbouring
territories
Females roam territories for larger males, more elaborate
physical features, display more energy in courtship activity
than other males
These features help the female choose the best male which
will give the offspring the best chance of survival
B) EXTERNAL VERTILISATION takes place in water
Fertilisation in bass & other aquatic animals is external
Female releases many unfertilised eggs into the water, at the same time- the
male also releases sperm which fertilises some of the eggs
Because fertilisation in water is not certain – bass must release huge numbers
of sperm – increases probability of fertilisation
Large number of fertilised eggs – enough offspring will survive and grow into
adults
Wasteful as huge numbers of eggs are released
Most eggs are eaten by other animals
Fertilisation is not certain
Reproductive energy – all goes into producing the huge number of eggs
C) INTERNAL FERTILISATION occurs in terrestrial vertebrates (reptiles, birds,
mammals)
Fertilisation is more certain as the sperm fertilise the egg inside the female
during mating
