Asynchrony within estrous synchrony among ringtailed lemurs (Primates: Lemuridae).

Area of Science:

• Primate reproductive behavior
• Lemur social dynamics
• Mammalian reproductive endocrinology

Background:

• Ringtailed lemurs (Lemur catta) exhibit seasonal estrous cycles.
• Understanding reproductive synchrony and asynchrony is crucial for primate behavioral ecology.

Purpose of the Study:

• To investigate the hypothesis of estrus asynchrony within synchronized estrous cycles in female ringtailed lemurs.
• To explore the functional significance of estrus asynchrony in mate choice and social dynamics.
• To re-evaluate current models of male primate group membership based on reproductive strategies.

Main Methods:

• Combined data from wild and semifree-ranging ringtailed lemur groups.
• Observed estrous overlap among adult females over multiple group-years.
• Utilized computer simulations to assess the probability of observed estrous patterns occurring by chance.

Main Results:

• Ringtailed lemurs display annual synchrony of estrous cycles but asynchrony of estrus, with minimal overlap among females.
• Computer simulations indicated that the observed asynchrony was unlikely to be random.
• A pheromone-based signal-response system is proposed to mediate both synchrony and asynchrony.

Conclusions:

• Estrus asynchrony in ringtailed lemurs likely maximizes individual female mate choice by reducing temporal competition.
• The findings necessitate revisions to current models explaining male presence in primate social groups.
• Further research into specific reproductive tactics is essential for developing comprehensive models of primate reproductive strategies.