ANT301 1nd Edition Lecture 7Outline of Last Lecture I. Hominoids a. Gorillasb. ChimpsII. Niche Outline of Current Lecture III. Niche parameter: dieta. Niche factori. Home range ii. Territory 1. Mate defense territoriality IV. Asymmetry in parental investment Current Lecture: Primate Social Behavior I. Key niche parameter: dieta. What an animal eats and can eat has a major impact on behavior, esp social behaviorb. Fundamental concept: females need more food than similar sized males die to the energetic costs of pregnancy and lactationII. Remember: a. In wild pop, most females either pregnant or lactatingb. Lactation most energetically stressful periodc. Not only feeding, but carrying III. Another key niche factor: how much space you use/ need/defenda. Home range- are where a primate group livesi. Consistent over timeii. Animals return to same food resources/ sleeping sites during the yearThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.iii. Home ranges of adjacent groups can overlap b. Territory- actively defended boundary of all or part of the home rangei. Co specifics (members of same species) keep outii. Key feature: social groups are trying or maintain exclusive access to resourcesiii. All primates have home ranges, Only some primates are territorial1. Gibbons are extremely territorial iv. Maintaining a territory is COSTLY v. Boundaries must be patrolled and defendedvi. Physical aggression very costly 1. Q: if territoriality is costly, why do some primates pay the price to be territorial?a. Defending resources (food)b. Defending mates 2. Q: when does it make sense to defend a resource?a. When its scarce and clumped (defensible) i. Gorillas eat leaves and other low quality vegetable matter (neither scarce nor clumped) no territorialityii. Gibbons eat ripe fruit (both scarce and clumped highly territorial vii. Mate defense territoriality1. Premise: females need more food than males2. Q: what is the limiting resource for males?a. FEMALES b. Sometimes territoriality seems to be about one male or a group of males defending access to females 3. Primate (Mammalian) reproduction:a. Q: what do females usually contribute?i. Egg, gestation, lactationii. Infant carryingiii. Long period of infant dependency/ learningb. Q: whats the minimum a male has to contribute (in most cases)?i. Sperm 4. Asymmetry in parental investmenta. Expectation: i. Males usually invest less. Should they be choosy or promiscuous? {to maximize reproductive success}1. PROMISCUOUS ii. Females HAVE to invest more. should they be choosy or promiscuous?1. CHOOSY5. Corollary: males doing their best to dominate female attention in order to exclude other males from mating opportunitiesa. Mate guarding- males guard females to control reproductive systemb. Phenomenon at the core of mate defense territoriality 6. Q: why is there permanent male female association in so many primates?a. If males (generally) don't contribute much to reproduction,why do females keep them aroundi. PROTECTION- males may help defend females and infants against predators b. Hired guns hypothesis: females associate with familiar males to prevent harassment from other malesi. Male harassment takes many formsii. Most severe infanticide 1. Ex. Lions- new male kills all the infants2. Infanticide is very common in primates kids take long to mature3. When does infanticide occur?--> reproductive benefit to the male (white sifaka)4. Why does the female mate with infanticidal male?a. Cutting her lossesb. Male has demonstrated his fitnessc. Sociobiology- describes the effects of male/female differences in reproductive biology on social behavior i. Everything stemming form the asymmetry in requiring parental investment by males and females ii. Q: aren’t there instances in which females reap a benefit of mating with more than one male?1. Callitrichids (platerines)a. Females mate with multiple males b. Males provide infant care because they have had matingopp with females and they might be hisc. Still related to reproductive biology (twinning)i. She gives birth to twins ii. Gives birth to 4 kids a yeariii. Kids can have 2 diff dads d. Female choosiness is an old idea:i. Formalized as “Bateman’s Principle”ii. Angus Bateman- fruit fliesiii. Provided empirical support for the notion that promiscuity more valuable to male that female reproductive successiv. ….but this is a generalization1. Ex. Mouse lemur (smallest living primate/ only mate for 12 hrs every year)- primate females that mate with multiple males as a strategy to avoid infanticidev. Just to convince you that sex strategy is related to investment in reproduction 1. Flicker- carves out the nest and incubating the chick while femalesgo get food 2. Females compete for access to males some females maintain 2 nests with 2 males mating partners a. Females maintain 2 nests with males b. Strategy is possible bc bird reproductive is diff from