[1] Australian Natl Univ, Sch Resource Management & Environm Sci, Canberra, ACT 0200, Australia
[2] Wildlife Management Int Pty Ltd, Sanderson, NT 0812, Australia
[3] Dept Lands Planning & Environm, Palmerston, NT 0831, Australia
[4] Trop Savannas CRC, Pk & Wildlife Commiss, Palmerston, NT 0831, Australia
[5] Australian Natl Univ, Stat Consulting Unit, Canberra, ACT 0200, Australia