An estimation of density and population size for Eld’s deer in the Xonnabouly Eld’s deer sanctuary, Lao PDR

Abstract

Abstract Eld’s deer (Rucervus eldi) was once thought to be extinct in the wild in Lao PDR. In early 2000, however, conservationists discovered that they still exist in Savannakhet Province. In 2004, the government of Lao PDR established the Xonnabouly Eld’s Deer Sanctuary with an area of about 93,000 ha. However, no population size estimates for this significant population are available for guiding conservation efforts of preserving this important species. In this study, we used the line transect method to assess the Eld’s deer density and abundance during the survey. During our surveys, we made 27 visual observations of Eld’s deer. We estimated the average detection probability to be 0.57 (CI: 0.45–0.72) and the average density to be 0.58 (CI: 0.33–1.01). We estimated the total number of Eld’s deer in the surveyed area of the Xonnabouly Eld’s Deer Sanctuary to be 173 (95% CI: 99–305). The population in the Xonnabouly Eld’s Deer Sanctuary seems to be the most important Eld’s deer population for R. e. siamensis subspecies as well as for the R. eldii, at least in the continental part of Asia. With the sharp decline of Eld’s deer populations in other protected areas (especially in Cambodia and Myanmar), we should pay special attention and give more priority on the conservation efforts of preserving the remaining population in Xonnabouly Eld’s Deer Sanctuary.