Lecture 5: Male Reproductive Behaviors Flashcards
What is the goal of male reproductive behavior?
To deliver male gametes (sperm) to female gametes (ova)
Since males have billions of gametes and females have few, how does this change their behavior?
Males: put little to no energy investment into reproducing
Females: put a lot of energy and resources into it, making them more “choosy.”
What theory states that organisms adaptively allocate their limited time and resources to maximize their relative reproductive success?
Life History Theory
Male sex behavior can be divide into two components ___ and ___.
What two components regulate these?
Sexual motivation (sex drive) and sexual performance (reproductive ability and success)
-Endocrine and nervous system
In the case of elephant seals, the males will fight for the best ____ beach areas because females prefer to have their pups near the water
Waterfront
In elephant seals, the low ranking males will often challenge the high ranking males (those at the waterfront) for a chance to mate. This is an example of ____ ____
Sexual motivation
What type of courtship behavior do manikins exhibit? What is it regulated by?
Wing snap; regulated by activation effect of androgens
In manakins, ____ activates specialized ___ neurons, which control wing movement and result in wing snap
Testosterone; motor neurons
According to the paper by Ronay and Hippel (2010) human males are more likely to show ___ ___ in front of a female observer ; they were also shown to have elevated levels of __
Risky behaviors; testosterone
Do androgens cause male reproductive behaviors?
No, they affect likelihood of mating behaviors by reducing threshold for behavior in the presence of the appropriate stimuli and social context
What are the three reproductive behaviors in males?
Mounting, Intromission (insertion of penis) and Ejaculation (release of semen)
What researcher determined the age at which male rats first exhibit copulatory behavior? Relevant findings?
-Calvin P Stone; evaluated presence of male reproductive behaviors
-The average age of first copulation in male rats is 50 days old!
After castration, male rats maintain copulatory ability for how many days?
14 days
Seasonal breeders display a ‘natural castration’ during non-breeding seasons in response to shorter or longer days (daylight). How does this affect the testes and gonadal hormone levels? Big point?
-Causes regression of testes and decline in gonadal hormone levels
-Therefore: testosterone treatment (but not necessarily testes) can restore sexual behavior in post-castration adult males
True or False: More testosterone is needed to restore vs. maintain reproductive behavior in males
True
The longer the period of mount latency, the lower the __ ___
Sexual motivation
What kind of test can be used to study male sexual motivation (sex drive)?
Obstruction Test
When ____, a region in the hypothalamus, is lesioned, male reproductive behavior in virtually every vertebrate species is reduced or eliminated
Preoptic Area
The pre-optic area affects sexual ___ but not ___
Sexual performance; sexual motivation
The ____, a brain structure, releases GnRH and is activated as soon as male meet receptive female
Medial POA
Blocking sense of smell, such as through olfactory bulbectomy, usually decrease ___ and ___ behaviors
Social and reproductive behaviors
(can also impact sexual performance and sexual motivation, with variable or conflict findings across studies)
The olfactory bulb projects to the ___ and that structure projects to the ____
Amygdala ; Medial Pre-Optic Area (mPOA)
In general, the ___—a structure in the brain—integrates sensory information, including relevant information for reproductive behaviors
amygdala
The basolateral amygdala is involved in ______ while the corticomedial amygdala is involved in _____
Sexual motivation; sexual performance
The enhanced and renewed mating performance by a male with a novel female, particularly after just mating with a female is known as the _____ ____
Coolidge Effect
