1. Unit 2 Mating and Parenting Chapter 12 Parenting

2. Success Success is measured by # of young that survive into adulthood and reprod themselves as well

3. 4 Factors led to the evolution of parenting: 1. Saturated habitats- more crowded, more parenting 2. Harsh/stressful environ- need parents or young will die 3. Specialized diet- learn what to eat 4. Predation pressure- young need protection

4. Who needs parents? More complex animals take longer to develop and need more parenting

5. (The Maury Povich Idea) There is less fathering when a male is not sure the child is his, but the female always knows its hers because: 1. Internal fertilization leads to more female care verses external fertilization 2. Proximity- female more likely near young when they hatch/born

6. Parenting variations Little parental care needed when young are precocial (born fully developed) Lots of parental care needed when young are altricial (born before development complete)

7. Little parenting Lay eggs and leave Young fend for themselves once born Ex: turtles Large grazing mammals are born able to run almost immediately

8. Ample parenting Animals that live in colonies Young born naked and helpless Ex: primates and birds

9. Nesting behavior Nest- structure for rearing young Greatest variety in birds Protection via location, camouflage, inaccessibility Incubation by body or materials Chicks have “egg tooth” to chip out Parents remove shell from nest

10. After hatching Imprinting- genetically driven Young will imprint on large object moving near them during a critical time window, most likely mother Necessary for survival FAP- fixed action pattern (instinct)

11. The most parenting Mammals Milk from female for nutrients Gestation varies- marsupials shortest Long learning process for young b/c survival depends on it

12. Tutoring and Play How to hunt Life skills practiced by playing Develop social skills and sexual behaviors required for survival

13. Group parenting More models for young to imitate Constant adult supervision Group bonds are strong Mothers are very protective Ex: wolves, lions

14. Unusual parenting strategies Unusual brooders- frogs hatch eggs out mouth, seahorse males give birth out pouch Brood parasites- birds lay eggs in another’s nest, nesting bird cares for all young not knowing Ex: cuckoos and cowbirds

15. Infanticide and cannibalism Killing of young Usually a new male will kill young of previous male One young receives food, other starves Older young harass younger

16. Why have more than one? Insurance If one dies, you still have another left Food supply If there is lots of food, more young can survive. Less food, parents must allocate resources

17. Natal dispersal Mov’t from birth place to place for first breeding Distance differs by gender Males usually leave Females tend to stay closer, more relatives around help raise young