10 3 2023 Announcements at 5 00pm ChimeIn Reminders Discussion Posts due by Friday Oct 6 at 5 00pm Submit a reply to another student s post by Sunday Oct 8 Your lowest 3 ChimeIn scores will be dropped Check you grades regularly If you notice an issue contact your TA 1 1 2 The Living Primates Part 3 Ecology Mating Social Systems Dr Carrie Miller Oct 3 2023 ANTH 1001 Fall 2023 2 1 Catarrhines hominoids Gorilla Mountain Lowland Gorillas Africa outside Congo River Knuckle walking on ground Largest ape Often 1 male multi female groups Eat mostly foliage some fruit 3 4 Catarrhines hominoids Pan Chimpanzees Africa outside Congo River Knuckle walking on ground Ripe fruit specialists Males intensely social and sometimes violent 10 3 2023 3 4 2 Catarrhines hominoids Pan Africa INSIDE Congo Bonobos River Knuckle walking on ground More diverse diet than chimps Females intensely social 5 6 10 3 2023 5 6 3 NOMENCLATURE OF THE APES Animals Chordata Mammals Primates Hominoidea Hominidae Hylobatidae Family Homininae Ponginae Hominini Gorillini Homo Pan Gorilla Pongo Hylobates Homo sapiens Kingdom Phylum Class Order Superfamily Subfamily Tribe Genus Species Where primates live what they eat Primate Ecology 7 8 10 3 2023 7 8 4 Primate habitats Where primates live Tropical rainforest or Tropical dry forest 10 3 2023 Woodland Gallery forest Savanna Primate diets What primates eat ChimeIn Which of these categories do you think most primates eat 9 10 Vertebrates Vertebrates Fruits Fruits s s t t c c e e s s n n I I L e a v e s Gums Saps Gums Saps 9 10 5 Primate diets What primates eat Primates eat many kinds of foods Plants Fruits flowers seeds leaves bark gum Trees vines shrubs herbs and grass Animals Insects vertebrates Fungi Mushrooms Minerals Soils clay salts Vertebrates Fruits s t c e s n I L e a v e s Gums Saps Insects insectivory High quality rich in protein fat Small items Distribution Mostly sparse unpredictable Large clumped sources usually well defended e g bees army ants 11 12 10 3 2023 11 12 Patas monkey 6 Termite fishing Strategies for extracting insects Fruit frugivory Fruits have evolved to be eaten seeds Plants manipulate animals to disperse their Attractively colored Full of high quality nutrients especially Well defended until ready to eat husks sugars rinds acids phytotoxins Fruit crops can be abundant Distribution Spatially clumped e g scattered big Varied availability over time trees 13 14 10 3 2023 13 14 7 Leaves folivory Extremely abundant Generally low in quality Evolved to NOT be eaten Plants solar panels and sugar factories Mainly cellulose indigestible Often defended with phytotoxins e g alkaloids tannins BUT young leaves high in protein Cellulose can be digested by bacteria in gut chambered stomachs or hind gut fermentation Distribution Mature leaves are abundant Young leaves more seasonal clumped Primate diets What primates eat 15 16 Vertebrates Fruits s t c e s n I L e a v e s Gums Saps 10 3 2023 15 16 8 Why do we care about ecology Informs our understanding of primate social mating systems 17 18 A framework for the evolution of primate social mating systems from a behavioral ecology perspective Wrangham s Socioecological model Ecological pressures Key strategy of females Distribution and relationships of females Key strategy of males Yes Do male strategies change optimal strategies of females No Social system 10 3 2023 17 18 9 What is a social system The number of males and females of all ages that live and interact together Solitary individuals Group living Characteristics of a social group Spatial and temporal proximity Coordination of activities Recognition of group members Greater Tolerance Communication Interaction Cooperation among group members than among non group members 19 20 10 3 2023 19 20 10 What are the benefits of living in a group Food access Wrangham s Resource Defense Model More eyes looking for resources Better able to defend resources Decreased predation van Shaik s Predation Defense model More eyes and ears to detect predators Geometry of the selfish herd Mob deterrence Increased access to mates Cooperation in rearing offspring What are the costs of living in a group Increased competition for food and resources Increased competition for mates Increased risk of predation Increased exposure to disease and parasites 21 22 10 3 2023 21 22 11 Social System Mating System 23 24 Mating systems Monogamy Polygyny Mono 1 gamos marriage union One male one female Poly many gyny women One male multiple females Polyandry Poly many andry men Multiple males one female Polygynandry Multiple males multiple females 10 3 2023 23 24 12 10 3 2023 Lemurs and Lorises American Monkeys African Asian Monkeys Apes Humans Polyandry Monogamy Polygyny Polygynandry Alouatta Indri Callicebus Lemur catta Cebus Presbytis potenziani Colobus guereza Papio anubis Tibet Hadza Hylobates Gorilla Pan25 Himba Mating systems Mating may occur with or without long term social relationships In many animals mating may be the only social interaction between the individuals Non social insects snails slugs etc Social system is not necessarily identical to mating system The observed mating system may not be identical to the genetically revealed mating system Extra pair copulations may and do occur Animals do not generally mate randomly BUT males and females often have different criteria and preferences for mates 25 26 26 13 What Do Females Want Resources Especially food needed to grow babies Fewer female competitors Mate choice Good genes Help with baby care Carrying feeding baby Babies not killed What Do Males Want Mating opportunities More mating opportunities Avoid baby care So they can invest more in more mating opportunities Paternity certainty Only their babies to survive Kill babies fathered by rival males 27 28 27 28 10 3 2023 14 Infanticide Why kill babies of rival males If unrelated they are genetic competitors Females may spend years nursing a baby Nursing suppresses ovulation pregnancy unlikely Killing a female s baby speeds time to next ovulation IF male is sure baby is not his AND killing baby will speed time to female s next ovulation AND he is likely to mate and conceive with female THEN killing baby can pay off for the male Naturalistic Fallacy IS implies OUGHT 29 30 10 3 2023 15 29 30 Conflict Between Males and Females What females want What males want Mate choice Paternity certainty fewer males competitors Fewer female competitors More mates Male help with baby care Avoid helping
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