Lifespan and Reproductive Senescence in a Free-Ranging Ring-Tailed Lemur (Lemur catta) Population at Berenty, Madagascar.

The lifespan and age-specific fecundity of female ring-tailed lemurs (Lemur catta) were estimated from a 24-year longitudinal dataset based on individual identification at Berenty Reserve, Madagascar. The mean lifespan of females in 10-year (1989-1998) birth cohorts was 4.9 ± 4.9 years (n = 77), and the longest recorded lifespan in the population was 20 years. The mortality rate of adult females increased to ≥20% at 10-11 years old and reached 33-50% at 12-15 years old. Although the birth rate of old females (12-17 years old) was 72.0%, slightly lower than that of prime adult females (4-11 years old), i.e. 80.2%, no significant difference was found between them. Half of the females who reached the age of 12 years gave birth in the last year of their life. The oldest mother to give birth was 17 years old. These results suggest that most females can maintain reproductive performance in their later life and that there is no evidence for a postreproductive lifespan in this species.