Male mating patterns in wild multimale mountain gorilla groups.

Area of Science:

• Primate Behavior
• Conservation Biology
• Animal Reproduction

Background:

• Mountain gorillas (Gorilla gorilla beringei) are often classified with a one-male mating system.
• However, a significant proportion (40%) of social units are multimale groups.
• Understanding mating dynamics in these multimale groups is crucial for accurate species classification.

Purpose of the Study:

• To investigate male mating patterns in multimale mountain gorilla groups.
• To analyze male-male mating harassment in relation to dominance rank and female reproductive status.
• To determine if subordinate males gain mating opportunities in multimale social units.

Main Methods:

• 17-month observational study of two multimale mountain gorilla groups in Rwanda.
• Detailed recording of mating behaviors, dominance interactions, and female reproductive states.
• Analysis of mating frequency, harassment incidents, and associated factors.

Main Results:

• Dominant males engaged in significantly more matings than subordinate males.
• Dominant males preferentially mated with cycling adult and pregnant females.
• Subordinate males were more likely to mate with subadult females, and multiple males mated with females near conception.

Conclusions:

• Multimale mountain gorilla groups can provide mating opportunities for subordinate males.
• Dominant males may not always prevent subordinate mating, suggesting flexibility in the mating system.
• Further research is needed on female roles and paternity to fully understand mountain gorilla mating systems.