March 2010 is Whio Awareness Month on the Tongariro River

Date:  03 March 2010

Whio on the Tongariro River

March 2010 is Whio Awareness Month. The whio, or blue duck, is one of New Zealand’s most endangered birds. There are only approximately 2500 whio left in New Zealand – a lot less than the number of kiwi.

The awareness month aims to increase public knowledge about the whio’s plight. It is an initiative of the Central North Island Blue Duck Charitable Trust (CNIBDCT), which was established in 2002 to enhance, protect and promote the whio.

About the whio

Whio Pair on the Whakapapa River

Whio are endemic to New Zealand, which means this is the only country they are found, and one of only four torrent ducks in the world.

They are adapted to living in one of the most challenging environments - a fast flowing river. "Ducklings are born to surf, able to negotiate white water almost straight out of the shell," says Kim Turia, Department of Conservation.

They have several unique physical features which are adaptations to this fast flowing environment. Their webbed feet collapse like a folded umbrella to create less drag, which allows the ducks to pull themselves forward through fast water. They also have a special soft lip on the end of their bill, which acts a bit like the head on a vacuum cleaner and allows them to scrape off insect larvae that cling to rocks.

Whio can be found in the central North Island. They are generally nesting between August and October and can lay 4 - 9 creamy white eggs at a time. The female incubates the eggs for 35 days, and after hatching both parents look after the young until they fledge at around 70 days old. By then the ducklings have learned to fly and will then leave their parents to find a mate and territory of their own. Whio can defend territories up to 1km long on the river and are with the same partner right throughout the year – some even mate for life. They are very aggressive and have even been known to tackle Canada geese that stray into their territory.

If you’re looking for whio they are most active during early morning or late evening. They have unique calls and are definitely not quackers, says Kim. "Instead the girls growl at the guys and the guys whistle at the girls. Sound familiar?"

Threats to the whio

Loss of habitat through changing land and water use has been a major threat to Whio over the years. They also nest in burrows and caves along the river bank which make them highly vulnerable to flooding. However, their biggest threat is introduced predators, and in particular the stoat.

Monitoring of whio on the Tongariro

Monitoring of whio on the Tongariro began late 2009 and is part of a five year monitoring plan, supported by CNIBDCT and Genesis Energy.

"Whio can’t live in just any old waterway," says Kim. "They need fast-flowing, high water quality, plants along the bank and lots of invertebrates. Fortunately, whio are increasingly making the Tongariro River their home. With Whio living on such an accessible river, anglers and other river users have the opportunity to see this rare and threatened native species close up in the urban and semi-urban surrounds of Turangi."

Advice for the public

"Whio may seem tame and unafraid, but for their safety we would be grateful if people would give them space and watch the birds from a distance, particularly when walking their dog," says Kim. "Dogs find the scent of ducks quite attractive, and can easily disturb a nest. Keeping your dog on a lead particularly during the breeding season is an excellent step towards helping this threatened bird."

Whio sightings

Sightings this season on the Tongariro River have been in the Fence Pool, Major Jones Pool, Boulder Pool, Blue Pool, between Kutai Street and the Major Jones Bridge. Ducklings have been seen at the Boulder Pool and the Blue Pool.

Recent projects

In 2008 local business people set up the Blue Duck Project Charitable Trust (Trust) to protect Whio on the Tongariro. Lead by Garth Oaken of Tongariro River Rafting and Craig Morey of Parklands Motel, their goal was to set traps the entire length of the river from the Poutu intake to Turangi Township, which they have just completed.

"Stage one involved setting 160 DOC200 traps which comprise of a strong steel trap in a wooden box along both sides of the river from the Major Jones footbridge to the fence pool" says Garth. "Volunteers check the traps regularly, and send the data back to me. To date they have accounted for over 270 pests including rats, stoats, weasels, hedgehogs and even a couple of wild cats. Stage two included the installation of traps from the Fence Pool to the Poutu Intake."

"Funding for this stage was received from the Waikato Catchment Ecological Enhancement Trust, which enabled us to purchase more than 60 new ‘Henry’ self setting traps," says Garth. "The advantage of the self-setting traps is that it traps, kills and releases the predator and then re-sets automatically. They are powered by a small CO2 cartridge which will enable a minimum of 12 kills before it needs to be replaced. The Henry will be able to be installed further upstream in the river gorge area where access is particularly difficult and will only need to be checked twice a year."

The Trust has been very pleased with the results so far and would like to acknowledge the Pharazan Trust, Turangi New World, founding trust member Nick Singers who was instrumental in getting the project off the ground and various other local businesses for their help.

The Department of Conservation is a big supporter of this programme, says Kim. “Without community involvement like this the work often won’t happen. It’s important to acknowledge their persistence, hard work and dedication they put into this project which has the objective of protecting the values of this important river.”

If you are interested in clearing and setting some of the traps, please contact Garth at www.trr.co.nz.

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