MOD 6 Sexual Selection BIRDS Flashcards
Why do birds have flamboyant ornaments or dance? And what ornament do window birds have?
Birds have ornaments or dance to attract mates and out-compete competitors.
Windows birds have long tails which attract mates
What is Sexual Selection?
Traits becoming more or less common depending on an individual’s ability to mate with more or better partners
How does natural selection play into sexual selection?
If a trait is developed which f
What is natural selection
When traits become more or less common depending on an individual’s ability to survive and gather resources
Intrasexual
“A” for Alpha which refers to MALE vs MALE in gender fights
How do males compete for mates?
by intimidating one another with ornaments e.g florescent colours/dancing
Intersexual
“ER” for EER I don’t know what to pick, as the FEMALE has the choice of the male she mates with
How do the ornaments (long tails and red patches) help the females when choosing a mate?
The ornaments create a ranking system that the females use to compare males to one another
What does it tell the female if the male has a long tail and vibrant colours?
That they are efficient at finding food as they require a greater calorie surplus to make the long tail
The vibrant colours present a healthy bird with a healthy immune system
What does “active nests” mean?
If a female is in the nest (tending to babies??)
CHECK
Is the number of active nests important? If so, why?
Yes. Active nests represent that the female is reproducing and passing on genes, which is good
What time would be the best time for the females to give birth? Spring OR Winter? And why?
Spring would be a better time to give birth as it would give the babies time to develop and grow before winter comes, which is harsh as food is scarce.
TRUE/FALSE: when baby chicks fledge and leave the nest they are in competition with one other.
TRUE, this also contributes to why fertilisation earlier is better as it gives them a better season to try and survive in.
What does having a shorter tail indicate in terms of mating?
Shorter tail - later mating season
***ASK
What does having a longer tail indicate in terms of mating?
Longer tail = more female attention as it has exceeded the tail length threshold
Why does having a longer tail increase female attraction?
Higher on the mate ranking scale and more intimidating to males
In the experiment, why must we need a glue-cut tails group?
The glue-cut tails group is a control group
They find out if the glue has an effect on mating
Was there any significant change in female attraction between the short-short tail, medium-short tail or the glue-cut tails group?
No difference
Why is food distribution important?
it can have a dramatic effect on what kinds of traits will be favoured by sexual selection.
Does clustered food lead to male-male competiton or female choice?
Clustered = male-male coompetition
What is a key example of sexual selection at work which we can see with the burly males vs females?
The males are burly and carry extra weight to fight off other males and keep their territory of food and win the female
The females don’t need the extra weight to survive, so are kept smaller and lighter
HOW CAN CLUSTERED BE IMPORTANT???
When does female choice occur and why? (with food placement)
Dispurtion = female choice
This is because the food is dispersed, the males can’t defend a territory of food, but rather have to convince the females that they are the best possible mate.
CAN BIRDS CHANGE THEIR APPEARACCNE TO BE MORE INTIMIDATING THAN WHEN THEY WERE BORN??
BIRD GYM?
TRUE/FALSE: the fancy traits increase forever
FALSE
The fancy traits increase until they inhibit their chances of survival
Why do the females not change in appearance?
Because natural selection still favours their camo colours and the extra weight or ornaments are unnecessary.
Natural selection (shortened version)
leads to adaptations for gathering resources and surviving
Sexual selection (shortened version)
leads to adaptations for gathering mates and breeding
