females that mate with greater than 1 male per season

• rarest form 
• female control or reversal of sex roles
• male biased OSR
• the multiple males have an equal opportunity to fertilize her eggs.
• due to limited # of territories

one male and one female per mating season

•  its rare for mammals
• males have low parental investment
• monogomy usually happens when the RS of the  male will increase due to their monogomy. So if they can provide food or protection to their young so that they survive.
• sometimes females will force males to be monogomous in matriarchial settings. 

• 3 hypothesis

1. Mate guarding
2. mate assistance
3. Female enforced

• female remains receptive after mating 
• females are difficult to locate and are widely distributed
• more males than females
• the male guards the female until she is ready to mate.

• with his care his RS increases
• his RS would not increase if he mated with more
• low densities

• female forces the male to stay with her otherwise she loses parental care 
• if male tries to attract another mate she will attack him

• males can contribute a lot = mate assistance
• food/protection
• males can't guard multiple nest effectively

extra-pair copulation

• leaving your mate to mate with another
• Risks: letting another male mate with your partner or females may lose favor of original male
• benefits: increased # of fertilized eggs and it might increase RS for some females

• Material benefits 

1. more resources
2. better protection
3. infanticide reduction

• Genetic Benefits

1. Fertility insurance- she gets all eggs fertilized. 
2. good genes hypothesis- males with best genes
3. genetic compatability- diverse genetics

males mate with more than one female in a mating season

• The most common
• 4 types

1. Female defense
2. resource defense
3. scramble defense
4. lek 

females choose males based on their resources so males defend their resources to get multiple females

• usually when resources are scarce
• females generally do better with monogomous males but depending on the quality of resources it may be in their best interest to mate with an already mated male. 

• resources/females are widely distributed
• males go out and look for females usually having a short reproductive period.
• males all try to find a mate quickly but also try to find a good mate

when males display in a group 

• 3 hypotheses

1. hot shot
2. hot spot
3. female preference

1. habitat quality is different
2. they can accurately assess the habitat quality
3. they can choose which ever they want (Ideal Free Distribution)

1. no free choice

2. don't know what the quality is

• low resources
• avoid inbreeding 
• Mate competition
• evaluation of breeding success

annual long distance travel from one place to another and then back (birds go south)

• lots of birds
• mammals (bison)
• reptiles (sea turtles
• costs are energy and predation 

1. to find food
2. to find water 
3. to reproduce
4. to get warm

1. Bias in OSR
2. differenceds in gametic contribution
3. parental investment

opperational sex ratio: the ratio of reproductive males to reproductive females. 

• when there are few females the males must compete

• male gametes are numerous and energetically inexpensive
• females gametes are few and more energetically expensive.

the amount of care one parent puts into thier offspring that decreases their reproductive success. 

• females generally have more parental investment than males

 Niko Tinbergen 

Konrad Lorenz(Austria)

Karl von Frisch

• genetic variation
• heritability of characteristics
• differential reproduction

traits that are attractive to females

• enforces competition between males
• female choice

male male competition

males compete for the rights to a female

when male has more parental investment and males have lower reproductive rates

happens when...

• Females compete for males
• OSR biased toward females

differences in male and female appearances

-color

- armaments

- size

a) friendship/ alliances

b) satellite behavior- subortinate males hang around dominate to intercept

1. nuptual gifts
2. helthy appearance

• hunting
• defense of territories
• better protection against predators
• thermoregulation

• exploitation by dominants
• reproduction interference
• increased competition for food
• increased exposure to parasites/pathogens

for sociality to evolve the benefits must be greater than the costs

1. selfish
2. spiteful
3. mutualism
4. reciprocal altruism
5. altruism

darwinian puzzle

game theory?

• requires long term associations between individuals
• and individual recognition

• a darwinian puzzle
• it might increase thier indirect fitness

• coopoerative care of the young
• reproductive castes cared for by sterile castes 
• overlap of generations

hymenopterans