- -
Goal of each species
↳
produce the maximum number of surviving offspring while
using the least amount of energy
(reproductive effort )
↳
unique reproductive strategies ensure maximum reproductive success in different environments ,
and survive reproductive age
enabling species to breed successfully to
2
types of reproductive strategies
:
strategy (elephant )
↳ ↳ K
r
strategy ( turtle )
-
-
rapid gestation long gestation
• •
laid few
many eggs offspring
• •
survival
few survive parental care to ensure
offspring
• •
little to no
parental care
•
Mortality survivorship curves
-
•
Convex survivorship curve CA)
↳ most
adulthood
offspring survive to
↳
mainly among older individuals
death occurs
Reason species have a high level of parental care
:
and
therefore a high survival rate ( K strategy )
-
•
Straight line
survivorship curve CB )
↳ with time
mortality decreases
steadily
↳
young individuals are as
likely to die as old ones ( birds plants )
,
•
Concave survivorship curve CC )
↳ adulthood
few offspring reach
↳ and
high mortality rate when
young as
offspring age ,
there is a decrease in
mortality
Reason :
species have no
parental care and therefore a low survival rate ( r strategy )
-
, A. Courtship D Amniotic
.
egg
B External . vs internal fertilisation E Precocial and altricial development
.
C. Ovi par , F. Parental
y ovovivipary and vivi par
y
care
A. Courtship
↳ behaviour 1
signals designed to attract another animal for
mating
① Simple
strategies
↳
chemical ( pheromones ) ,
visual ( bright colours ) or
auditory stimuli are used for mates
and do
e.
g birds sing special song
.
a special plumage
② Complex
strategies
↳
females favour males that are :
larger
•
•
have more elaborate physical features
display more
energy in courtship activity than other males
•
↳
helps female to choose the better male, which can reinforce pair bonding and promises
healthier
offspring
e.
g Blue cranes
.
do elaborate dances and a
complex and extended series of calls
How will courtship maximise reproduction ?
ensures that males and females find suitable mates (strongest male )
•
so that males and
sexual behaviour is timed females
ready for mating at the same
•
are
time
energy expenditure is
by the male the females conserves her
energy for breeding
•
,
Goal of each species
↳
produce the maximum number of surviving offspring while
using the least amount of energy
(reproductive effort )
↳
unique reproductive strategies ensure maximum reproductive success in different environments ,
and survive reproductive age
enabling species to breed successfully to
2
types of reproductive strategies
:
strategy (elephant )
↳ ↳ K
r
strategy ( turtle )
-
-
rapid gestation long gestation
• •
laid few
many eggs offspring
• •
survival
few survive parental care to ensure
offspring
• •
little to no
parental care
•
Mortality survivorship curves
-
•
Convex survivorship curve CA)
↳ most
adulthood
offspring survive to
↳
mainly among older individuals
death occurs
Reason species have a high level of parental care
:
and
therefore a high survival rate ( K strategy )
-
•
Straight line
survivorship curve CB )
↳ with time
mortality decreases
steadily
↳
young individuals are as
likely to die as old ones ( birds plants )
,
•
Concave survivorship curve CC )
↳ adulthood
few offspring reach
↳ and
high mortality rate when
young as
offspring age ,
there is a decrease in
mortality
Reason :
species have no
parental care and therefore a low survival rate ( r strategy )
-
, A. Courtship D Amniotic
.
egg
B External . vs internal fertilisation E Precocial and altricial development
.
C. Ovi par , F. Parental
y ovovivipary and vivi par
y
care
A. Courtship
↳ behaviour 1
signals designed to attract another animal for
mating
① Simple
strategies
↳
chemical ( pheromones ) ,
visual ( bright colours ) or
auditory stimuli are used for mates
and do
e.
g birds sing special song
.
a special plumage
② Complex
strategies
↳
females favour males that are :
larger
•
•
have more elaborate physical features
display more
energy in courtship activity than other males
•
↳
helps female to choose the better male, which can reinforce pair bonding and promises
healthier
offspring
e.
g Blue cranes
.
do elaborate dances and a
complex and extended series of calls
How will courtship maximise reproduction ?
ensures that males and females find suitable mates (strongest male )
•
so that males and
sexual behaviour is timed females
ready for mating at the same
•
are
time
energy expenditure is
by the male the females conserves her
energy for breeding
•
,
