Unit 2- Courtship Flashcards
Define Polygamy
A harem of females with one male eg. Deer
Define Monogamy
Each individual only shares gametes with one individual e.g. Birds
Define Promiscuity
When males and females mate with multiple partners eg. Gorillas
What is a fixed action pattern?
Instinctive behaviour triggered by a specific stimulus and once this behaviour is triggered it will run to completion.
Define sexual dimorphism
The difference in characteristics between the 2 sexes of the same species as a product of sexual selection.
What does sexual dimorphism usually result in?
The male being larger/ more heavily armoured/ more brightly coloured.
Females are more drab and small as they often look after the young and therefore must be camouflaged from predators to protect their offspring.
What does reverse sexual dimorphism mean?
This occurs when females are larger than males eg. Angler fish.
Describe the dominant male strategy for successful reproduction
Males must outfight their rivals and the selection is for bigger males with weaponry and strength
Describe the satellite male strategy for successful reproduction
Males have good displays and the selection is for physical or chemical signals and often complex patterns of movement or signals and response.
Describe the sneaker male strategy for successful reproduction
These are often smaller than females and will pretend to be females to get close enough to reproduce or alternatively sneak their way into females den/habitat.
What is the lek?
A neutral area in which two or more males perform a courtship display and the females visit to select their mate.
What are the main reasons for forming a lek?
- Forming a group increases the ratio of visiting females to males
- Allows females to compare males within the group, selecting a dominant male
- Subordinate or satellite males, have more of a chance of mating by being where the females are and by being around more “impressive” males
What is female choice influenced by?
FEMALES ASSESS MALE FITNESS
- Physical appearance or display- indicates gene selection
- Chemical signals- also indicates genetic markers
- Presence/absence of parasites
- Earlier life history events- in particular birds imprinting in early life history can determine mate choice later on.
Define imprinting
The innate irreversible developmental processes that take place in a young bird during a critical time period. Imprinting may influence mate choice later in life as the young animal learns the characteristics of a desirable mate.
