Morphometrics and testicle size of rain forest lemur species from southeastern Madagascar

Abstract

Six species of prosimians inhabiting the montane rain forest of the Ranomafana National Park located in southeastern Madagascar were captured, weighed, and measured during the months of May or June of 1987, 1988, and 1989. There were no significant differences in body weights and measurements between male and female Eulemur rubriventer (red-bellied lemur) or Eulemur fulvus rufus (red-fronted lemur). Adult female Propithecus diadema edwardsi (Milne Edward's sifaka) were heavier than males but the difference was not significant. A few Avahi laniger laniger (woolly lemur), Hapalemur aureus (golden bamboo lemur) and H. g. griseus (gentle bamboo lemur) also were captured and measured. Body weights of the same individual adult P. d. edwardsi changed over the three years, suggesting variation in food availability. Although there was no difference in body weight among adult males of two groups of P. d. edwardsi, one male in each group had a testicular volume four times larger than that of other males, even though these measurements were taken five months after the breeding season. These data suggest that only one adult male mates in each group. Testicular size of the polygynous E. f. rufus males was significantly larger than that of the monogamous E. rubriventer.