Genetic Variation and Differentiation among Insular Populations of the Small Indian Mongoose (Herpestes javanicus)

Abstract

The small Indian mongoose ( Herpestes javanicus ) was introduced onto many islands of the Caribbean and the major Hawaiian islands between 1877 and 1890. A Jamaican population (derived from India in 1872) was the source of animals for most introductions, and sizes of founder colonies ranged from about four to 300 individuals. Protein electrophoresis indicated that genetic isolation of mongoose populations on Jamaica, Saint Croix, Hawaii, and Oahu for ca. 100 years has been accompanied by relatively minor genetic changes. All alleles detected in the Jamaican population were detected in populations on Saint Croix and Hawaii, and 93% of the Jamaican alleles were detected in populations on Oahu and Puerto Rico. Allelic frequencies were similar among insular populations and resulted in little genetic divergence (D = 0.005). Levels of mean heterozygosity (H = 0.035) were comparable to those for mammals and were not significantly different among populations. Although the initial founding of the Jamaican population likely did not contain all of the alleles present in native populations of the small Indian mongoose, further reduction in genetic variation due to additional founding events was not evident. Rapid population growth is proposed as the mechanism responsible for the absence of reduced genetic variation among subsequent populations of the small Indian mongoose founded by small numbers of individuals.