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Flashcards in Animal Societies Deck (18):

What 3 types of mating systems are there

1. Monogamous
2. Polygamous
3. Promiscuous


Define monogamy, serial monogamy and lifetime monogamy

Monogamy - only breed with one mate per season

Serial monogamy - find a new mate each season. Common in territorial animals

Lifetime monogamy - mate together for their lifespan


What are the benefits of monogamy

Fitness - can mate with someone who produces high quality offspring

If resources are scarce reproductive success may be higher so male can help raise and defend offspring


What are the 2 types of polygamy

1. Polyandry - females mate with multiple males

2. Polygyny - males mate with multiple females


What is female defence polygyny

Females - have a shirt lifespan, are grouped together and only use sperm from one male

Males - give their sperm to all females in the same area so they can’t mate with other males


Give an example of a polygamous method to mating

Leks - arena for mating defended by males
Males mate with many females in the lek e.g sandflies mate with all visiting females


What is the sexy son hypothesis

Females will mate with attractive males so their sons will possess the genes to be attractive to females


What are 3 benefits to polyandry in social insects

1. Sperm replenishment

2. Replacement of inferior sperm

3. Protection from predators


What is a type of promiscuous mating system

Polygyandry - several males pair with several females


What is a cost to females of promiscuous mating

Sperm carries diseases
Greater quantity of sperm they receive, higher risk of disease


How do resources affect polygynous mating

Females follow resources - more resources they have the more offspring they produce e.g food, protection

Males follow females, more access to females more offspring they produce

If resources are fairly spread, females are widely dispersed and it benefits males to mate with more than 1 female


How does the threshold model affect polygynous mating

Females have equal fitness by mating with a male with more than 1 mate. Territory and food supply may be better than other males even if being shared among more than 1 female


Give an example of the threshold model

Female birds
Need shade in their territory
Will become a secondary female if their is shade


What is an extra pair copulation

Males and females who mate with others in nearby territories


What are 4 benefits of extra pair copulations

1. Increases the chances of all eggs being fertilised
2. Increases direct benefits e.g food
3. Maximises the genetic diversity of offspring
4. Can select males with good genes


What is sperm competition

Direct competition between multiple males sperm to fertilise an egg


Give an example of sperm competition

Dung flies - longer the copulation, more of the previous males sperm is displaced


What is the kamikaze sperm hypothesis

Natural selection favours sperm designed to kill other males sperm over fertilising the egg