Spot­ting the rare whio

Taupo & Turangi Weekender - - Front Page - Lau­rilee McMichael

It’s rare, shy, elu­sive, en­dan­gered… and if you’re lucky, you might be able to stand on the side of State High­way One and spot it.

It’s New Zealand’s na­tive blue duck, the whio, which lives in clear, fast-mov­ing moun­tain streams and eats mayflies, stone­flies and cad­dis flies, us­ing its unique lip to scrape food off rocks. With its habi­tat threat­ened by en­vi­ron­men­tal pol­lu­tion and its pop­u­la­tion dec­i­mated by pests, the ducks have been re­treat­ing into the back coun­try for decades.

But a na­tional pro­gramme to save the whio, partly based out of the Ton­gariro Na­tional Trout Cen­tre, and pest-trap­ping to re­duce the num­bers of preda­tors prey­ing on the ducks is pay­ing div­i­dends in the Cen­tral Plateau. To many peo­ple’s ex­cite­ment, whio have been reg­u­larly spot­ted on the Ton­gariro River just un­der the main road river bridge.

The news is also good on the west­ern side of Mt Ton­gariro where an an­nual whio sur­vey of the Whaka­papa, Man­gatepopo and Whanganui rivers found that the whio pop­u­la­tion has soared from 30 pairs in 1998 to 130 pairs and 252 duck­lings counted last De­cem­ber, largely thanks to sta­ble river flows dur­ing nest­ing and brood rear­ing and ef­fec­tive preda­tor con­trol.

Blue duck typ­i­cally in­habit clean, fast-flow­ing streams in forested up­per catch­ments of rivers and their big­gest en­emy is the stoat, which at­tacks fe­males on the nest, steals eggs and takes young duck­lings. They are also vul­ner­a­ble to feral cats, do­mes­tic dogs and fer­rets, with rats and pos­sums also con­sid­ered a threat.

Dave ‘Didymo Dave’ Cade, first spot­ted whio near the main road bridge on the Ton­gariro River a cou­ple of years ago but says they have been show­ing up more reg­u­larly over re­cent weeks. First he saw a sin­gle one and then last week ago he spot­ted a pair, and says lo­cal fish­er­men have seen more.

He says that’s not only great for the ducks, which are clas­si­fied ‘na­tion­ally vul­ner­a­ble — threat­ened’ but great for peo­ple too, who may have the op­por­tu­nity to spot these rare birds for them­selves.

“I just find it in­cred­i­ble that peo­ple can go down there and stand on the banks and see them be­cause they have al­ways tra­di­tion­ally been back coun­try and you couldn’t get to them.

“Even an 80 year old could walk to those places and see whio and we’ve never seen that be­fore. I don’t know of any other lo­ca­tions in New Zealand you can see whio from State High­way 1.” Whio have also been spot­ted on the Hine­ma­iaia Stream near the main road bridge, Dave says.

While the whio’s suc­cess story is due to sev­eral fac­tors and num­bers have been ris­ing over the en­tire cen­tral North Is­land over the last 14 years, whio on the Ton­gariro River have had a team of lo­cals look­ing out for them. Ton­gariro River Raft­ing owner Garth Oak­den set up the Blue Duck Project Char­i­ta­ble Trust nine years ago. It now has traps from Tree Trunk Gorge to the main road bridge as well as on the Whaka­papa and Man­ganui-o-teAo rivers. When the project be­gan there were three pairs on the Ton­gariro, and now there are around 30, Garth says.

“I couldn’t be prouder of what we’ve achieved but we couldn’t do it with­out our vol­un­teers, they’re key to the whole thing.”

He said with the whio now mov­ing into ar­eas where there were also peo­ple, dogs must be kept un­der con­trol near the river.

Cam Speedy, a trustee on the Cen­tral North Is­land Blue Duck Trust, says see­ing whio on the lower Ton­gariro River mir­rors a gen­eral re­gion-wide ex­pan­sion of whio in the area which has seen the birds find­ing new ter­ri­to­ries.

In one case, a bird banded on the Whaka­papa River in 2007 was later found with a mate liv­ing on the head­wa­ters of the Ran­gi­tikei River in the Kaimanawas, 64km away.

Re­gion-wide con­ser­va­tion ef­forts, in­clud­ing the Blue Duck Project Char­i­ta­ble Trust on the Ton­gariro, the Con­ser­va­tion Depart­ment and Gen­e­sis En­ergy’s Whio For­ever part­ner­ship, be­gun on the Ton­gariro River in 2004 and spread na­tion­wide, con­ser­va­tion by lo­cal hapūr Ngāti Hikairo, the Sika Foun­da­tion Whio Ini­tia­tive and work by ecol­o­gist Nick Singers on the Waimarino River head­wa­ters, had all con­trib­uted to the pop­u­la­tion thriv­ing, Cam said.

Photo / File

Con­ser­va­tion work and preda­tor con­trol is help­ing whio re­turn to Cen­tral Plateau rivers.

Photo / Dave Cade.

A pair of whio un­der the State High­way One bridge over the Ton­gariro River in Tu¯rangi.

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