Department of Conservation | Te Papa Atawhai
https://www.doc.govt.nz/
Survey of the distribution and abundance of blue duck (whio) in Kahurangi National Park 2009
Blue duck/whio are nationally endangered. This 2010 survey compares data to a previous one done over the summer of 1999/2000 to estimate the population in a number of the rivers in the north west catchments of Kahurangi National Park.