Transcript BREEDING SYSTEMS AND REPRODUCTIVE STRATEGIES OF …

BREEDING SYSTEMS AND
REPRODUCTIVE
STRATEGIES OF MAMMALS
BREEDING SYSTEMS: COMPETING
INTERESTS OF MALES AND FEMALES
• Description of mating behavior and
parental care by both sexes
• Parental care & potential rate of
reproduction of each sex
Reynolds. 1996. Animal Breeding Systems. TREE
OSR = operational sex ratio = ratio of available adult females to males
*Time budget for males = competition for mates and/or advertisement –
*Females invest in gametes & care (lower rate & resource limits) –
BREEDING SYSTEMS: COMPETING
INTERESTS OF MALES AND FEMALES
• Are the result of a “battle” of competing
interests between the sexes
COMMON TYPES OF BREEDING
SYSTEMS IN MAMMALS
COMMON TYPES OF BREEDING
SYSTEMS IN MAMMALS
Polygamy
COMMON TYPES OF BREEDING
SYSTEMS IN MAMMALS
Polygamy
•
Polyandry =
???
COMMON TYPES OF BREEDING
SYSTEMS IN MAMMALS
Polygamy
•
Polygyny =
•
2 types
COMMON TYPES OF BREEDING
SYSTEMS IN MAMMALS
Polygamy
–
Polygyny
• Female (harem)
defense
COMMON TYPES OF BREEDING
SYSTEMS IN MAMMALS
Polygamy
–
Polygyny
• Male dominance
BREEDING SYSTEM AND
DEVELOPMENT AT BIRTH
• Lactation believed to precede evolution of
parental care
• Review of 500 placental species indicates:
– Monogamy
1) large litters
2) altricial young
3) short gestation
BREEDING SYSTEM AND
DEVELOPMENT AT BIRTH
• Polygyny
1) small litters (<2)
2) precocial young
3) longer gestation
4) greater maternal investment before
parturition
BREEDING SYSTEM AND SIZE
OF MALES AND FEMALES
• Monogamous
• Polygynous
BREEDING SYSTEM AND JUVENILE
DISPERSAL
Natal Dispersal in Mammals is Male-Biased
–
–
frequency & distance
Females philopatric
M
F
F
Mom
F
M
BREEDING SYSTEM AND
JUVENILE DISPERSAL
The Inbreeding-Avoidance Model
BREEDING SYSTEM AND
JUVENILE DISPERSAL
Effects of Inbreeding on Mammals
– inbreeding depression
• decrease in fitness of offspring
– Homozygosity
• deleterious, recessive alleles
BREEDING SYSTEM AND
JUVENILE DISPERSAL
Effects of Inbreeding
on Mammals
–
field studies
• white-footed mice
Effects of Inbreeding on
Mammals
golden lion tamarin
BREEDING SYSTEM AND
JUVENILE DISPERSAL
Fit of the InbreedingAvoidance Model?
BREEDING SYSTEM AND
JUVENILE DISPERSAL
Fit of the Inbreeding-Avoidance Model?
– Monogamy: sex bias in dispersal?