CLIMATE AND REPRODUCTIVE SEASONALITY IN 2 FREE-RANGING ISLAND POPULATIONS OF RHESUS MACAQUES (MACACA-MULATTA)

We gathered data over a 3-year period (1988-1990) on two free-ranging, island populations of rhesus macaques (Macaca mulatta) to test hypoth eses concerning birth seasonal asynchrony and the relationship between climate and reproductive seasonality. Rhesus macaques from Kashmir, I ndia, were translocated to Key Lois in 1973 and from Key Lois to Racco on Key in 1978. Both sites are low-lying mangrove islands in the Flori da Keys. Floral diversity and abundance are greater on Raccoon Key tha n on Key Lois. Average maximal and minimal temperatures per month did not vary significantly between Raccoon Key and Key Lois over the 3-yea r period. Average minimal temperatures per month on Key Lois, but not Raccoon Key, varied significantly between years. There were no signifi cant variations in either the amount or the dates of rainfall over the 3-year period for the study area. A combined total of 1524 births was recorded for Raccoon Key (N = 879) and Key Lois (N = 645). The birth season on Raccoon Key began 6 weeks earlier than on Key Lois. Births w ere associated with wanner, rainier months on both islands. Conception s were associated with cooler, drier months at both study sites. No si gnificant correlations were found between the date of the onset of the summer rains and either median conception or median birth dates on Ra ccoon Key or Key Lois. Our results do not substantiate the hypothesis that the onset of rainfall, within the temporal period set by photoper iod, regulates seasonal reproduction in rhesus macaques. We suggest th at reproductive seasonality in the study populations may be influenced by a variety of factors.