The aerial survey of wildlife, including elephants, in Southern National Park using the aerial sample count i.e. systematic aerial assessment. The survey was carried out during the dry season (January to February) of 2007.
Source:Fay, M., Elkan, P., Marjan, M. and Grossmann F. (2007). 'Aerial surveys of wildlife , livestock and human activity in and around existing and proposed protected areas of Southern Sudan, dry season 2007, phase I'. Juba, South Sudan: Wildlife Conservation Society.