Reproductive Performance of the Captive Asian Elephants in Large Camps

Abstract

In Thailand, many elephants are used in tourism, with populations sustained by captive breeding. Many camps have breeding programs, but not all are successful. This study summarizes reproductive performance of elephants at seven tourist camps based on 4 to 21 years of breeding records. Age pyramid structures varied across camps, skewing older or younger, indicating differences in breeding success. Reproductive rates averaged 24.5 ± 8.9% and varied significantly across camps (2.8 – 69.2%). Based on parity, 76.5% of elephants were nulliparous, 8.2% produced one calf, and 15.2% were multiparous, with significant camp differences. Camps reported 1.10 ± 0.46 (range, 0.03-3.55) births per year, with a total of 19.6 ± 9.3 (range, 1-71) calves per camp. The age at first calving was 19.2 ± 1.1 (range, 8 – 40) years, mean inter-birth interval was 4.4 ± 0.2 (range, 1.8 – 7.9) years, and average gestation length was 653.9 ± 6.9 (range, 578 – 743) years. Birth sex ratio of all camps combined skewed slightly towards males - 1:0.75 (79 males: 60 females). Rates of abortions/stillbirths averaged 13.6%, and ranged from 3.5 – 75%. There were no obvious differences in management (e.g., number of bulls, estrous detection methods, work activities) that explained the range in breeding success, although lack of bull interest was a concern. This information can guide future studies to determine how specific practices affect reproductive performance, and emphasized the importance of breeding records to aid population management of captive elephants in Thailand.