A recent survey of the Wangapeka/Fyfe whio security site in Kahurangi National Park found 43 breeding pairs of blue duck/whio, with several kilometres of waterway still to be surveyed. This is up from 29 pairs in 2012/13 when the last dog-assisted census was carried out.
Ten pairs were found on 10 km of the Fyfe River which is the best whio habitat within the security site; an increase from two pairs in 2006. At one pair per kilometre, this is almost full capacity for the fiercely territorial whio.
Kate Steffens, DOC Senior Ranger Biodiversity, attributes the rapid increase in whio numbers to aerial 1080 operations across the entire whio security site in 2011, 2014 and 2016, combined with intensified trapping and Whio Operation Nest Egg (WHIONE) with the support of Genesis Energy.
“Whio are highly sensitive to stoat predation. Monitoring has shown that up to 90% of nests fail, 60% of fledged young are killed and around 50% of adult females can be killed during the moult period (when they are flightless) in areas where these predators are not controlled.
“Spikes in the number of ducklings produced in 2011, 2014 and 2016 clearly show the positive impact of aerial 1080 predator control on nesting success.
“There were 48 ducklings recorded in 2011 following an OSPRI aerial 1080 operation. DOC’s Battle for our Birds operations in 2014 and 2016 also resulted in high duckling numbers of 65 and 40 respectively. Numbers for the intervening years were 21, 18 and 23.”
The whio security site, centred on the Wangapeka and Fyfe river catchments, is one of eight nationally, which aim to ensure whio survive in the wild through DOC’s partnership with Genesis Energy in the Whio Forever Project.
The whio security site was first launched in 2003 when one pair of whio was found across 10 km of waterway, and the first 3.6 km of trap-line was installed.
Genesis Energy has supported the Whio Forever programme in the Wangapeka/Fyfe since 2011. Funding has been used for the Whio Operation Nest Egg (WHIONE) programme, more regular trap checks and replacement of the entire trap network from single-sets to double-sets. There are now 1054 traps across 83.4 km of waterways at the site.
The objective of the Wangapeka/Fyfe whio security site is to maintain a sustainable population of at least 50 pairs, which is within sight of being achieved.
Local volunteers from Tapawera community maintain the front-country trap-lines in the Wangapeka catchment, while DOC staff and contractors manage the back-country trap-lines.