Both the fieldwork and analytical work was supported by grants from the National Geographic Society and the Knickerbocker Foundation. The Department of Environment and Tourism of Namibia granted permission to carry out the work in Etosha National Park and made facilities available at Namutoni and the Mushara water hole. We wish to express our gratitude and thanks to these organizations for their support.
The field work could not have been carried out without the extensive support given the project and ourselves by Ginger Mauney. Elsabé Garstang, Helen Mohrmann, and Gwen Spicer were full partners in carrying out the field measurements. Johannes Kappies and other National Park personnel assisted with many of the field operations. Logistical and administrative support as well as preparation of the manuscript was provided by Mary Morris. Acoustic data analysis was provided by Dimitri Ponirakis and Melissa Fowler. Katharine Garstang provided graphics assistance. We wish to express our heartfelt thanks to all of these individuals for their help.
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