The genetic diversity and population structure of 136 captive Thai elephants (Elephas maximus) with known region of origin were investigated by analysis of 14 highly polymorphic microsatellite loci. We did not detect significant indications of inbreeding and only a low differentiation of elephants from different regions. This is probably explained by the combined effects of isolation by distance and exchange between different regions or between captive and wild elephant populations. Estimates of effective population sizes were in the range of 90-240 individuals, which emphasizes the necessity to guard against inbreeding as caused by the current use of a restricted number of breeding bulls.

Numbers of the Asian elephants (Elephas maximus) population are declining due to poaching, human-elephant conflicts, capture of wild calves for tourism and export and habitat destruction, which also may cause inbreeding in fragmented populations. In order to contribute to a reversal of this trend, we have developed an identification and parentage test by evaluation and selection of markers from 43 microsatellite loci that have been previously described for Asian or African elephants. Testing these markers on a panel of 169 Asian elephants comprising the 23 mother-offspring, 13 father-offspring and 13 parents-offspring pairs yielded 26 polymorphic markers. However, only 14 of these were found to be suitable for an analysis of molecular diversity, 12 of which will be implemented for an identification and parentage test to control the capture of wild calves in Thailand and neighboring countries.