24 terms

Behavioral Ecology Exam #3 Part 2

parental investment
expenditure on present offspring that increases that offsprings chance of survival at the expense of future offspring.
intra-sexual selection
favors traits that affect the ability of members of the same sex to compete with each other for mates
inter-sexual selection
favors traits that attract members of the opposite sex
male-male competition
(lots of competition) strong relationship to physical attributes and the number of matings they have. Defend mating sites, defend mates, ability to avoid damage
types of defense of mating sites
emergence, foraging, and oviposition
pre-copulation mechanisms
skill in mate location, time of emergence
post-copulation mechanisms
mate concealment, mate guarding
mate concealment
remove females from area, reduce conspicuousness of courtship
post-fertilization mechanisms
induced abortion, infanticide
induced abortion
"bruce effect" pregnancy disruption in which exposure of female to a new male results in abortion
when female is with young she is not able to mate, so males will come and kill her young so she can mate.
mate guarding
last male to mate often fertilizes most eggs
sperm competition
scrappers, copulatory plugs
to remove previous males sperm
copulatory plugs
"chastity belts" closes off females area so no sperm can enter
female choice
costly to mate with bad male (reduced fitness) so they choice good males
preferential mating
rejection of members of wrong species, selection of partners with resources, selection of partners with good genes.
direct benefits
better resources, increased parental investment
indirect (genetic) benefits
increased offspring fitness
nuptial gifts
resources given to increase length of mating or decrease probability of female mating again
secondary sexual characteristics
physical or behavioral characteristic that appear in sexually mature animals, differentiate between the sexes without having direct reproductive function
fischer's runaway hypothesis
1. trait starts by conferring some advantage
2. preference for trait that confers advantage evolves
3. eventually the offspring of these matings with have genes for traint and genes for prefeering trait
4. leads to a runaway process- prefenece is given even though the exagerated trait no longer confers a fitness
handicap hypothesis
signals are costly so they information conveyed is honest and shows males genetic quality (peacocks)
hamilton and zuk
disease resistance, colorful displays often signal health and parasite Resistance