Distribution, Abundance, and Putative Ecological Strategy of Macaca fascicularis on the Island of Mauritius, Southwestern Indian Ocean

Abstract

We estimate that between 25,000 and 35,000 long-tailed macaques, Macaca fascicularis, live on the island of Mauritius, 1,865 km², in the western Indian Ocean, and we detail their distribution on the island. Probably introduced to Mauritius at some time in the 16th century, the macaques have been implicated by a succession of authors as agents both in the extinction of the bulk of the island’s unique vertebrate fauna, and in the destruction of its indigenous vegetation. Some of them have gone so far as to suggest that in view of their depredations the macaques should be eradicated from Mauritius. However, studies of the behavior and ecology of the macaques in both degraded savanna and native forest habitats, supplemented by surveys around the island, cast doubt upon this putative destructive role. Macaque population densities in Mauritius range from a maximum of around 1.3 individuals/ha in degraded savanna formations, to a minimum of approximately 0.33 individuals/ha in indigenous forest, and reflect a clear preference among these primates for secondary environments. Thus the long-tailed macaques in Mauritius, as in their southeast Asian homeland, best fit the profile of a ‘weed’ species that has simply exploited the disturbance by humans of the indigenous vegetation. They do not at the present time appear to pose a major threat to what remains of the remarkable indigenous vertebrate fauna of Mauritius, although they may help to disperse the seeds of invading exotic plant species in what remains of the indigenous forests.

Unusually High Frequency MHC Class I Alleles in Mauritian Origin Cynomolgus Macaques

“…Anthropological and historical evidence suggests that the macaques were introduced to the island ϳ400 years ago by European seafarers (60). mtDNA analysis of Mauritian origin macaques supports the existence of a population bottleneck at the time of introduction; in fact, the founding population may have included only a single female (61).…”

“…Additionally, the blood samples were obtained on two different occasions, further increasing the likelihood that the results are extensible to the general population of Mauritian macaques. Cynomolgus macaques, as a species, are highly adaptable and can thrive in a variety of ecological niches, particularly those disrupted by human activity (60). Mauritius is Ͻ2000 km (2), with unequal monkey distribution throughout the small island.…”

Simian Immunodeficiency Virus SIVmac239 Infection of Major Histocompatibility Complex-Identical Cynomolgus Macaques from Mauritius

“…The limited MHC repertoire of MCM may reflect selective advantages of these haplotypes for the Mauritian environment. It appears more likely that the limited MHC diversity described here is the result of a classic population bottleneck or founder effect (22,30,36; A. J. Tosi and C. S. Coke, submitted for publication). Consequently, there is little reason to assume that the relative genetic homogeneity of MCM is restricted to the MHC.…”

“…Remarkably, both MHC-identical animals exhibited mutations in these regions, though the affected amino acids were distinct in each animal. With the exception of the Tat [26][27][28][29][30][31][32][33][34][35][36] region, strong CTL responses were detected at 3 weeks postinfection in at least one of the two animals (data not shown), strongly suggesting that the shared variability results from immune escape.…”

“…Historical records suggest that European seafarers introduced cynomolgus macaques to the small Indian Ocean island of Mauritius within the last 500 years (36). Mitochondrial and Y chromosome DNA analyses indicate that the current MCM population of between 25,000 and 35,000 monkeys descended from a very small founder population that is most likely to have originated from Sumatra and has remained isolated for approximately 80 to 100 generations (22; A. J. Tosi and C. S. Coke, submitted for publication).…”