14 Parental and Mating Behavior

any parental expenditure that benefits one offspring at a cost to the parents’ ability to invest other aspects of fitness.

includes the wellbeing of the existing offspring, parents’ future reproduction, and inclusive fitness thru aid to kin

parental investment

patterns of parental fitness should maximize what?

an individual’s reproductive fitness overall

includes behaviors that have an immediate physical effect on the offspring and their survival

direct parental care

example of direct parental care

centipede care for her eggs

includes behaviors that do not have an immediate physical effect on the offspring

indirect parental care

example of indirect care

Bower bird building a nest

Indirect behaviors include

building nest or den

establishing a territory

defending critical resources

defending young from predators

caring for the pregnant female by the male

conflicts among family members over parental investment (affect fitness)

sexual conflict between the evolutionary interests of male and females

intrabrood conflicts btwn members of the same litter/brood

interbrood conflict btwn members of the current brood+future offspring

sexual conflict ties into what two concepts?

Bateman’s hypothesis and intersexual selection

Whose idea was an expansion of Bateman’s principle?

Trivers

what are sex differences in parental effort important for?

determining the strength of sexual selection

“Sibling rivalry”

conflict between members of same litter/brood

individual offspring derives greater fitness from parental care received personally THAN from parental care bestowed on siblings

Intrabrood conflict

example of intrabrood conflict

puppies competing for mother’s teats

intrabrood rivalry

offspring will kill another

siblicide

when a sibling almost always ends up being killed. older/stronger sibling will kill

obligate siblicide

may or may not occur, based on environmental conditions. ie when food is scarce

facultative siblicide

conflict btwn members of current nd future offspring

interbrood conflict

factors that influence allocation of resources by parents

life history

certainty of paternity

gender of offspring

In most species the greater the chance that it will reproduce only once the greater is the amount of parental investment

TRUE

models the tradeoffs between reproduction, growth and survivorship

reproductive value model

defined as its expected contribution to the population thru both current and future reproduction

RV (organism’s reproductive value)

represents an organism’s future reproductive thru its investment in growth and survivorship

residual reproductive value

predicts that higher investment in current reproduction hinders growth, survivorship, and reduces future reproduction… while investments in growth will payoff with higher fecundity and rep. episodes in the future.

Cost-of-reproduction hypothesis

the way in which parents invest resources btwn male vs female offspring

restricted to dioecious species

sex allocation

male or female for their entire lifetime

dioecious species

what species has highest number of biparental care?

birds

what group has highest number of maternal care?

mammals

sex role reversals: the ratio of potentially mating males to fertilize females to females

male-biased

operational sex ratio

maximum number of offspring that each parent can produce per unit time

potential reproductive rate

manipulation and use of host individuals either of the same (intraspecific) or different species (interspecific) to raise the young of the brood-parasite

brood parasitism

organisms that use the strategy of brood parasitism

brood parasites

involves one parent depositing its eggs into the nest/care of a conspecific

intraspecific brood parasitism

involves a parent depositing her eggs into the nest/care of a host of another species

interspecific brood parasitism

unable to build a nest of their own(for interspecific)

obligate brood parasites

way in which a group is structured in relation to sexual behavior

mating system

one male nd one female have an exclusive mating relationships

monogamy

is a mating system w more than one partner. there are three different types

polygamy

one male has an exclusive relationship with two or more females

most common system among vertebrates

polygyny

one female has an exclusive relationship with two or more males

polyandry

slight variation of the other two, where two or more males have an exclusive relationship with two or more females

polygynandry

a member of one sex within the social group mates with any number of the opposite sex

promiscuity

an exclusive sexual relationship btwn a female and a male based on observations of sexual interactions

sexual monogamy

refers to DNA analyses confirming that a female-male pair reproduce exclusively with each other

very rare in nature

genetic monogamy

proposes that polygyous matings are beneficial to females when the benefits achieved by mating with high quality male and by gaining access to his resources increase her reproductive fitness over the costs involved

polygyny threshold hypothesis

lady has mated with a genetically superior male her, so her offspring will have a genetic advantage. this is conferred to her sons increasing their chances for reproductive success

Sexy-son hypothesis

the male herds the females into a cluster. allows them to be protected by the male, while male has continuous access to the females, and prevents other males from mating with them

female defense polygyny

where the male guards a resource that the female needs for reproduction

resource defense polygyny

male defends a symbolic territory located at a traditional display site

lek defense polygyny

a gathering of males, of certain animal species, for the purposes of competitive mating display

lek