1. Mating Strategies Monogamy Polygamy Polygyny: one male, 2+ females
Polyandry: one female, 2+ males
Promiscuity: no pair bond

2. Sexual Selection Females assess males b) Males battle for access
to females

4. Life History Patterns Cost of reproduction Senescence age-related
Reproductive effort
Cost of reproduction
Senescence
age-related
experience-related
Previous breeding experience

5. N. Elephant Seals Iteroparous, one offspring per year,
Polygynous, K-selected and long-lived
Iteroparous, one offspring per year,
8-month gestation
Males breed at age 7-8, females at 2-3
Sexual selection by male battles, only
female raises pup

6. Western Gulls Iteroparous, multiple offspring, lay 2-3 eggs per year
Monogamous, K-selected and long-lived
Iteroparous, multiple offspring, lay 2-3
eggs per year
Third Chick Disadvantage
Males breed at age 3-5, females at 4-6,
both sexes raise young

7. New study by Dr. Tim Clutton-Brock (Cambridge Univ.)
(2007, Proceedings of the Royal Society)
Renowned expert on life history studies
in long-lived mammals
Review of polygynous vs monogamous species:
males live longer in monogomous
in 16 of 19 polygynous species, males have
significantly shorter lifespan
cost of reproduction—defending a harem