In mid-1907, David was invited to join Ernest Shackleton's Antarctic "Nimrod" Expedition, and, in December, won Australian government funding for the expedition. The same month he left for New Zealand with Leo Cotton and Douglas Mawson, two of his former students. David was nearly 50 years of age and it was intended that he would stay only until April 1908, but en route to Antarctica on the he altered his plans and decided to stay for the entire duration of the expedition.