Male alternative sexual strategies: When your not the biggest and the best.

1

• Male alternative sexual strategies When your not
  the biggest and the best.
• or for that matter if your late to the party

• Interference
• Deception
• Sneak copulations

2

• Male alternative conditional sexual strategies
  Marine iguanas
• Larger males will interfere with copulations
• Smaller males compensate with a pre-ejaculate of
  old sperm which seeps

3
Male inherited alternative sexual strategies
Paracerceis sculpta

• The 3 male morphs with distinct reproductive
  tactics
• ?-males are largest possess elongated uropods and
  comprise 81 of the male population
• ?-males are smaller than a-males, comprise 4 of
  male population
• resemble females in their behavior and external
  morphology
• invade spongocoels by mimicking female behavior
• ?-males are smallest, comprise 15 of aggregate
  male population
• Use their small size and rapid movements to
  invade spongocoels (From Shuster 1992).
• Male morph differences are the result of genetic
  differences.

In order for three morphs to exist they MUST
exhibit equal reproductive success
4

• Do we have different and evolved sexual
  strategies?
• Phenotypic (conditional)?
• Genotypic (inherited)?

5
Males just dont give up Sperm competition

• The contest between sperm from two or more males
  for the fertilization of ova.
• Penis morphology
• Sperm morphology
• Sperm concentration
• Sperm motility and
• Directional movement
• Sperm longevity
• Chemical composition of semen

6
Does mate guarding affect mating success?

• Seychelles Brush-Warbler males vigorously guard
  females until they deposit their single egg
• They then switch to egg protection and abandon
  mate guarding

Seychelles Brush-Warbler
7
Mate guarding affects mating success During
female receptivity

• Experiment
• Place egg in nest to fool mate guarding males
  into switching to nest guarding
• Measure extra pair male intrusions and
  copulations in control vs. manipulated

8
Mate guarding DOES affect mating success
Egg placed in nest
9
Mate guarding affects mating success After the
fact
Many insect males ride on top of the female for
prolonged periods of time after mating to
discourage other suitors.
Wheel Bugs
Tiger beetles
Millipedes
10
Do humans exhibit mate guarding behaviors?
Buss DM. Human Mate (2002). Guarding.Neuro
Endocrinol Lett. 23 (4)23-9.
Mens mate guarding, relative to that of womens,
is strongly triggered as a consequence of being
mated to young and physically attractive women,
being confronted by interested rivals who have
superior economic resources or prospects, and
having a mate who displays signs of sexual
involvement with a rival. Womens mate guarding,
relative to that of mens, is triggered as a
consequence of being mated to men high in income
and status striving, rivals who are more
physically attractive, and having a partner who
shows signs of emotional involvement with another
woman. Behavioral output of mate guarding
adaptations range from vigilance to violence.   
11
Female mate choice Its all about the looks?
12
Mate choice Its all about the genes, looks are
an indicator
Better looking/behaving
Healthy male
Fewer parasites
Sexual selection
Less predation
Good genes
Pre-sexual selection
Healthy offspring
Variability in looks/behaviors
Variability in predator defenses
Variability in parasite succeptability
The cycle of consistent selective pressure for
genes that indicate quality can cause runaway
selection.
13

• Are we better looking that we were?
• Or just cleaner