1 Department of Geography, National University of Singapore, 1 Arts Link, 117570, Singapore. Electronic address: dan.friess@nus.edu.sg.
2 Australian Rivers Institute and School of Environment, Griffith University, Southport, Qld 4222, Australia. Electronic address: joe.lee@griffith.edu.au.
3 Conservation Programmes, Zoological Society of London-Philippines, 43-E Burgos Street, Barangay Magdalo, La Paz, 5000 Iloilo City, Philippines. Electronic address: jurgenne.primavera@zsl.org.