New Zealand, but the progeny are returned to their respective island. South Island whio are held and bred in captivity on the South Island only. All captives are kept by approved and permitted zoological and wildlife facilities as part of the national recovery plan. As part of this current ten-year plan (2009–2019) is the WHIONE program which works with specially trained nose dogs to locate nests. The eggs are removed, and the ducklings hatched and raised in captivity. Later they are conditioned for coordinated release. Blue ducks were presented to the International Waterfowl Association in the UK in the 1970s along with New Zealand shovelers, New Zealand scaup, and brown teal by The Wildlife Service of New Zealand. The species was maintained in the UK until at least 2012 before dying out; efforts to create the only captive breeding population outside of New Zealand with these ducks ultimately failed when the last two male ducks formed a same-sex relationship with each other instead of with the female that was assigned to them. They have not been known to be exported and maintained anywhere else internationally. Status The blue duck is classified as Endangered by the IUCN due to its highly fragmented and shrinking population, and it is listed as Nationally Endangered in the New Zealand Threat Classification System. A 2010 census estimated a total population size of 2,500–3,000 individuals, with a maximum of 1,200 pairs. The blue duck is a very localised species now threatened by predation from introduced mammals such as stoats, competition for its invertebrate food with introduced trout, and damming of mountain rivers for hydroelectric schemes. Early recovery efforts by scientists, field workers and volunteers have been summarised in a project sponsored by Genesis Energy, the Central North Island Blue Duck Charitable Conservation Trust and the Royal Forest and Bird Protection Society in 2006. In 2009 the New Zealand Department of Conservation started a ten-year recovery programme to protect the species at eight sites using predator control and then re-establish populations throughout their entire former range. Female whio are especially vulnerable to stoats while nesting, and some populations are now 70 percent male. In one study area, clutches of eggs lasted an average of nine days before being destroyed by stoats, and the one brood that hatched was killed the next day. In 2011 the New Zealand Department of Conservation and Genesis Energy started the Whio Forever