A stochastic simulation model for Asian elephant Elephas maximus populations and the inheritance of tusks

Abstract

Tiedemann R. and Kurt F. 1995. A stochastic simulation model for Asian elephant Elephas maximus populations and the inheritance of tusks. [In: Ecological genetics in mammals II. G. B. Hartl and J. Markowski, eds]. Acta Theriologica, Suppl. 3: 111-124. In the framework of available historical data on population size and human impact on the Asian elephant Elephas maximus Linnaeus, 1758, we developed a stochastic simulation model for elephant populations, which simulates individual elephants and includes their geno-and phenotype regarding the tusk character. The model omits density dependence of reproduction parameters and mortality rates. The model pre-dicts female mortality and mean calving interval to be the paramount factors deter-mining the long-term population trend. For simulated female mortality rates of 5% and 5.5% a mean calving interval of 5.2 years and 4.4-4.5 years, respectively, leads to stable populations, which is in accordance with values derived from field ob-servations. Taking into account a higher mortality of tuskers due to human impact, frequencies of the tusk allele were simulated both for dominant and recessive in-heritance of the tusk character. The best accordance with census data was achieved, when the tusk allele was assumed to be dominant, combined with a slight reproductive advantage for tuskers. Since the model simulates population dynamics and tusk allele frequencies under various mortality schedules, it can be used to predict the effect of conservation efforts on populations of the Asian elephant.