Chapter 11 book (exam4) Flashcards
Reproductive Value
Measures of the potential of an individual to leave surviving descendants in the future
- Value depending on ecological or social circumstances into which it’s born Value than influences amount of care parent is willing to provide
- Parents use behavior to determine how to allocate food most effectively
Signal of Need Hypothesis
Signals that advertise an offsprings level of need in order to maximize their chance of being fed
-Example: Cries loudly and pushes head above siblings
Signal of Quality Hypothesis
Signals that advertize and offspring’s quality or merit in order to maximize their chance of being fed by their parents
Ex: bright red mouth lining can signal healthy nestling
Ecological Variation of Food
Plentiful food = they feed neediest
Low/unpredictable food = they feed the strongest
*Mouth color in some avian species may help parents find hungry mouths rather than signal quality
Altricial
Young that reside in nest for an extended period of time
Precocial
Young that are mobile soon after hatching
- American coot parents commit infanticide and peck their young to death
- Beggin less reliable when parents produce larger or more broods
- Red mason bees can sex of an egg. Give females more attention since males don’t live as long
Local Competition Hypothesis
When related individuals compete for resources or mates, then one sex is more costly to produce
Local Enhancement Hypothesis
When one sex provides resources or enhances the mating success of its relatives, then that sex is cheaper to produce
Seychelles Warbler
On low-quality territories where food was scarce, parents produced male offspring that tended to disperse from the territory. ON high-quality territories where food was plentiful, parents produced more females that tended to stay on the territory as helpers
Trivers-Willard Hypothesis
Mothers can adjust
offspring sex ratio according to their own body condition
- In most polygynous species, the sex with higher reproductive variance is male because only one of a few males monopolize most of the reproduction
-Mothers that bias the sex-ratio towards daughters produce 29% more grand offspring. Those that bias towards sons produce 25% more offspring
- Human women with abundant food access are slightly more likely to have sons
-Mukogodo Tribe: 67 boys for every 100 girls, girls have better reproductive chances than men. Why? mothers nurse girls longer, take them to the doctors, and remain closer to daughters vs sons
Parent-Offspring Conflict
Evolutionary conflicts arise from differences in optimal parenting investment in the offspring from the standpoint of the parent vs. the offspring
-Parents can interfere with siblicide should it be in their interest to do so
Reproductive Insurance Hypothesis
Mothers in siblicide species lay a 2nd egg as insurance against hatching failure
Facultative Siblicide Hypothesis
Parents permit siblicide behavior only when resource availability is low
-Sandpipers leave eggs with male and forgo mothering duties
Paternity Assurance Hypothesis
Males should only provide care when they are certain to be fathers of the individuals they are feeding
- In monogamous broods, increased male feeding leads to higher fledgling success
- Fish, Frogs (some poisonous), and waterbus moisten eggs outside of water and parental costs are greater for females - they need more prey due to large egg size
- Female Mexican-free tail bats can find their own offspring 80% of the time among thousands of young
- Barn swallows vs. Bank Swallows- can tell their brood apart based on vocalization
Interspective Brood Parasite
when an animal exploits the parental care of individuals of other species *also occurs in bees and other insects
-Cuckoo chicks match the call of the reed warbler - successful nest parasite
