Why Lemurs Are Different

Long-term studies have contributed invaluable data regarding distribution, biogeography, physiology, behavior, and ecology of Madagascar’s primates. Lemurs contrast with many other primates in several behavioral features. What are these features?
1. Females Dominate Males
- Female dominance is variable, but still the common pattern
2. Female-Female Aggression
- Some lemurs have dominance hierarchies, some only seasonally
- Targeted and severe aggression emerges seasonally
3. Lack of Sexual Dimorphism
- Regardless of social system
- Sexual Dimorphism – morphological differences between the sexes
4. Many Monogamous Species
5. Sperm Competition Combined with Male-Male Aggression
- Example – copulatory plug
- Sperm competition – competition for fertilization occurring among sperm
6. High Infant Mortality
- Short gestation length and low litter weight
7. Cathemerality in Some Species
- Cathemeral – active during both the day and night
8. Low Metabolic Rate
9. Strict Breeding Season
So why are these lemurs so different? Many believe climatic unpredictability is associated with unpredictable fruiting and flowering, which have shaped the evolution of these distinctive features. Others think island isolation coupled with these factors is also possible. It is not clear which of these specifically has contributed, but is most likely a combination of these factors and other species-specific features. Therefore, is it Madagascar that is different, rather than the lemurs that inhabit it?
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Sources: Caption photo, Indri pair, Madagascar climate, topic