BZ 300 1st Edition Lecture 20 Outline of Last Lecture I. Mating Systems continued…a. Polygynyi. Male Dominancy Polygyny1. Lek2. Example: Male Sage Grouse3. Why a Lek?b. Monogamyi. Why?ii. Malesiii. Femalesc. Polyandryi. Classicalii. Cooperatived. Polygynandry and Promiscuityi. Advantages of Polygynandryii. PromiscuityII. Hormones and Sexual BehaviorIII. Good Genes Modela. Other Genetic Considerations for Mate Selectioni. Assess Inbreeding/Outbreedingii. Major Histocompatability Complex Lociiii. Fluctuating Asymmetryiv. PlumageIV. Nesting, Parenting and Territorialitya. Teaching vs. Observational Learningi. Nesting1. Examplesb. Parental Investmenti. Can Take Many Formsii. Life History Traits1. R-selected2. K-selectedOutline of Current Lecture: I. Parental Investment Continued…a. Factors that Favor Parental Careb. Who invests and Why?i. Uniparental Caregivingc. Male Parental Care is not uncommon, why?These 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.i. Internal Fertilizationii. External Fertilizationd. Biparental Caregivinge. Hormones and Parental Carei. Prolactinf. Parenting and Conflicts of Interesti. When should parental behavior cease?ii. Treatments of siblings similar to parenting COIiii. Begging and Weaningiv. Sibling Conflictv. InfanticideII. Aggression and Territoriality a. Aggressioni. Agonismii. Types of Aggressioniii. Ritualizationb. Territorialityi. Home RangeCurrent Lecture:I. Parental Investment Continued…a. Factors that favor parental care:i. Stable, saturated habitat with a lot of intraspecific competition. Parental investment is favored in competitive environments, where young need a big head start.ii. Stressful physical conditions, primary the extremes. Extreme cold, hot, etc…iii. Specialized diet (learning)- parents need to guide child into learning the methodsiv. Predator pressure- if it is high, parental investment must be high to protect the children until can care for themselvesv. Clutch size- how many offspring there isvi. Parental Investment can change across lifetime. Animals, who reproduce later in life, do not have to worry about taking care of children for a very long time so they can put all of the focus on their one animal.b. Not so much as if an animal invests, but WHO invests and WHY?i. Uniparental caregiving: rules of anisogamy remain true. Anisogamy- female is the primary caregiver. ii. Investment favors correct ID of own young, recognition cues. Do not want to be investing young with those not related to you. This is highly developed in social animals. iii. Birds and marine animals use auditoryiv. Terrestrial animals use olfactory (Look in book for Cow, Calf olfactory cues)v. In terrestrial animals, Internal fertilization is common. A large variation in how animals care for eggs and young1. Ex. Cockroaches: deposit ootheca, carry ootheca, retract ootheca, Diplotera transfers nutrient2. Reptiles- bury eggs carefully, guard eggs give birth3. Male uni-parental care giving is popular in seahorses, etc. vi. Parental care and external fertilization1. Fish- scatter gametes, deposit gametes, nests, mouth brooders2. Amphibians- egg guarding, midwife toad, salamandersc. Male Parental Care is not uncommon, why?i. Male investment can be significant (e.g., spermataphores, valuable territory) Things can get complicated and unpredictable once it goes beyond the gamete itself. ii. Certainty of paternity is important1. Internal fertilization: male has less certainty of paternity2. External Fertilization: if associated with territory or something to defend, than male has a high certainty of paternity. This will enhance investment in offspring.d. Biparental caregiving: compare fitness gains- biparental vs uniparentali. Biparental care is favored if by leaving, the male reduces fitness and the offspring don’t survive (resources, guarding, long parental care period). A male that leaves under these conditions: not guarded enough, not taught well enough, do not have enough nutrients to get by, his fitness will still be zero even though he did reproduce. 1. Ex. Djungarian hamster, Siberian Hamstere. Hormones and Parental Behaviori. Prolactin1. Neuropeptide from anterior pituitary ertebrate maternal care2. Stimulates nesting behavior3. Inhibits Ovulationii. *Note: Look in book for other hormones!f. Parenting and conflict of interesti. When should parental behavior cease?1. Increasing demands of young not matched by increasing benefits for parents2. Young are demanding more, but are at a decreasing chance of being at risk3. It no longer pays for parent to be investing and providing for offspring4. It never becomes too expensive for offspring to be invested by parent. They become more and mores selfish. Benefit of parent is diminishing. ii. Treatments of siblings similar to parenting COI1. Parents are equally related to all offspring2. Offspring are 100% related to itself, but often times only 50% related to sibling3. Siblings do not tend to share investment from parents4. Parents benefit from cooperation5. Parental interest may be served by sterile castes (ch. 13)iii. Begging and Weaning1. Begging- a way to attract food. Honest or dishonest signal?a. May be dishonestb. Informs parent about food needsc. Can be very expensive if it alerts predators of presence of nest. Parents are favored if they do central place foraging, more food, less trips, less chances to alert predators. d. Nest Parasites beg more vigorously2. Parent- offspring conflict over weaningiv. Sibling Conflict1. Some offspring may have a better chance of surviving than others2. Inequalities in survival probabilities3. Resource limitation4. One strategy for parents is too have more offsprings than could survive called an “insurance egg”. This than sets the stage for sibling-sibling conflict.5. In an unpredictable environment it may be better to have more offspringthan can afford. 6. Parents do not intervene in siblicide- parents benefit from survival of a few strong young. v. Infanticide- killing of very young animals1. Males- tend to kill animals when the paternity of males is uncertain2. In primates two type of infanticide- divert infanticide0a. Concealed ovulationb. Promiscuous/ polgynyandrous copulation3. Females- kill offspring. Under different conditions, know offspring is their own but if resources are limited they essentially kill offspring and save it for the future coop.4.