Musth cases in two captive male Asian elephants (Elephas maximus) in Korea.

Importance: When male elephants reach sexual maturity, they exhibit excessive sexual behaviors called musths. The musth period is important in the management of elephant herds. However, the timing of the musth and the effect of musth elephants on non-musth elephants in Korea have not been clearly analyzed.

Case presentation: In our observations, one male elephant (Koshik), who had been alone with a female, was observed to be on musth from age 15, while another young male elephant (Udara), who joined the group later, was not observed to be on musth at age 15, moreover the male elephants that were found to be on musth earlier had a longer duration of musth after the introduction of the other male. Furthermore, we also found that Koshik's testosterone levels increased approximately 200-fold during musth (the lowest level was 0.93 ng/mL) compared to before musth (the highest level was 214 ng/mL).

Conclusions and relevance: We found that the duration and behavior of musth in captive male elephants were affected by the introduction of other growing male elephants.