4/17/18 Sex and Reproduction I. “primate reproductive strategy” variation of key char. across primates II. how and why do males and females differ in repro. strats.? III. is sex just about reproduction in NHPs? Reproductive Strategies A trade-off: parental investment – mating effort E.g Low parental. high mating; high par. Low mate (invest more in parenting) o Primates lower mating effort and invest heavily in offspring (fewer, invest more) o E.g. rat produce big litters, reproduce again quickly (brief duration) Life history variables: key maturational & reproductive char that define the life course, vary o Gestation length: 2-8.3 months (mouse lemur vs gorilla) o Birth weight: <10g-2000g o Weaning age: <50 days-4 yrs (then resume sexual repro) o Age at sexual maturity: <1->9yrs Timing of reproduction: some breed year round, others show reprod seasonalty o Breeding & births concentrated (what ecological factor account for this ?) Seasonality in food availability Time reprod- most energetically expensive = most food [pregnancy? After?] Lactation is most, have babies when most food avail. (they don’t do this consci.) Ex- macaques (asia, nor afr.)extrm seas habitat Nor Jpn Himalayas, birth=2 mos. More moderate period 4 mos confinement, tropics: year round (in relatn to env) NW monkey: squirrel monkey, birth synchrony: w/in 6 wk period see most birth Not associated w/ peak food; maybe predation pressure : infant survival expected to be greater when several mothers present, great vigilance; perhaps dilution effect as well- pred go for weak/slow and only 1 infant?
You've reached the end of your free preview.
Want to read all 3 pages?
- Spring '16
- Jillian Maloney
- Reproduction, w/ multi males, multi M/F, w/ monogamy male, likely mate w/, w/ peak food