Asian Elephants Are Not Self-sustaining in North America
Publication Type: |
Journal Article |
Year of Publication: |
2000 |
Authors: |
Robert J. Wiese |
Publication/Journal: |
Zoo Biology |
Keywords: |
declining population, demography, elephant, elephas maximus, fecundity, mortality |
Abstract:
Demographic analysis of the captive Asian elephants in North America indicates that the population is not self-sustaining. First year mortality is nearly 30%, but perhaps more important, the fecundity is extremely low (Mx = 0.01–0.02) throughout the prime reproductive years. Without continued importation or a drastic increase in birth rates, the Asian elephant population in North America will drop to approximately 10 elephants in 50 years and be demographically extinct. Model mortality and fecundity curves needed to establish a self-sustaining Asian elephant population in North America show that fecundity must increase four to eight times the historical rates. Emerging techniques such as artificial insemination may assist in making the goal of a self-sustaining population more realizable by allowing reproduction by the numerous females that do not have access to a male, but other obstacles exist as well. A self-sustaining population will present challenges such as maintaining the significant number of male offspring that will be produced. Importation of young females from documented self-sustaining populations overseas is one option that would alleviate the need for a self-sustaining Asian elephant population in North America and the number of imports per year would be minimal.