H Flashcards
What is a mating system?
A mating system is the way an animal population is structured in relation to reproductive behaviour.
Types of Mating systems?
Monogamy, polygyny, polyandry, promiscuity
What is monogamy?
One male is paired with one female.
Types of Monogamy?
- Life-long monogamy: A pair remains monogamous for multiple seasons.
- Serial Monogamy: A pair is monogamous for one breeding season, then switches partners.
Extra-Pair Copulations (EPCs)
Even in monogamous species, individuals may copulate with others outside their pair.
Extra-Pair Paternity
DNA fingerpainting can reveal that offspring in a nest may have different fathers.
Why is social Monogamy Common in Birds, but rare in Mammals?
- Mate-Assistance Hypothesis: Biparental care improves offspring survival.
- Mate-Guarding Hypothesis: Males stay with females to prevent them from mating with others.
Mate-Assistance Hypothesis?
- Biparental care is easier for birds than mallals.
Bird embryos develop in eggs, allowing both parents to incubate. - Mammalian embryos develop inside the female, limiting male involvement.
Mate-Guarding Hypothesis?
Males remain close to their mates to prevent other males from mating with them, increasing the chance that they father all offspring.
What is polygyny?
Polygyny is when one male mates with multiple females.
Types of Polygyny?
- Harem Defense Polygyny: A male defends a group of females from other males (ex: Nothern Fur Seals).
- Resource Defence Polygyny: A male defends a valuable resource that attracts females (ex, Red-Winged Blackbirds).
Polygyny Threshold Model
Predicts when a female should choose an already-mated male on a high-quality territory over an unmated male on a poor-quality territory.
What is Polyandry?
One female mate with multiple males.
Types of Polyandry
- Sequential Polyandry: A female mates with one male, lays eggs, then mates with another (ex: Sea Dragons).
- Simultaneous Polyandry: A female mates with multiple males at the same time (ex, African foam-nesting Frogs)
What is Polygynandry?
Occurs when multiple males and females mate, and all care for the offspring (ex: Dunnocks, Acorn Woodpeckers).
What is Promiscuity?
When both males and females mate with multiple partners but do not pair-bonds (ex: Bonobos).
Example of socially Monogamous Mammal?
North American Beavers (Castor Canadensis).
Example of a Monogamous Lizard?
Singleback Skinks (Australia) - males help defend offspring from predators.
Example of a Monogamous Fish?
French Angelfish - Paris defends territory and offspring as a team.
Example of a Harem-Defending Polygynous Species?
Northern Fur Seals - Males defend groups of females.
Example of resource-defending polygynous Species?
Red-winged Blackbirds - Males defend marsh territories that vary in quality.
Example of Sequentially Polyandrous Species?
Sea Drangons - Males incubate eggs in a pouch.
Example of Simultaneously Polyandrous Species?
African foam-nesting frogs - Males mix sperm into foam nests.
Example of Polygynandrous Species?
Dunnocks - Mating system depends on territory overlap.
Example of a Promiscuous Species?
Bonobos - Mating occurs without long-term pair bonds.
