Ducks Unlimited NZ

Displaying items by tag: Monitoring

Tuesday, 27 August 2019 21:01

Kiwi call monitoring at Tawharanui

In New Zealand we have our special icon, the Kiwi. This is the only country in the world where Kiwi live. They make their burrows in the undergrowth and enjoy running about searching for worms and spiders.

However, with such a lot of predators now, it is wise to have Kiwi either in a safely fenced or pest monitored area. At Tawharanui we have just that right situation, with the Predator Proof Fence across the Tokatu Point at the termination of Tawharanui Peninsular, giving freedom to all native creatures within.

Kiwi breed around Autumn each year, once they are old enough. This is about two years old. They like to call at twilight which is the two hours after the sun goes down. So Kiwi Call Monitoring  occurs when volunteers sit during those two hours usually 6 – 8pm, in June each year, silently listening for the calls.

Once the first call is heard then a count is  commenced, slowly, sometimes reaching to over 20 times. These are usually the male birds with their shrill high whistles. Then occasionally a  female will call with her lower guttural tones. Sometimes, all is then quiet. Perhaps they have found their mate!

Once the two hours is completed the volunteers collect together again at their base for supper and a chat about their evening event.

Sitting out in the dark at this time can be very cold in New Zealand. So good warm woolly and dry clothing is essential. Usually dry nights with little wind are chosen. The moon is rarely visible. Try it sometime – it’s a thrilling experience!

Patti Williams



Published in Issue 157
Tagged under
Tuesday, 27 August 2019 17:41

Operation Duck Pond

With about 90 percent of New Zealand’s wetland lost over the past 150 years, Fish & Game NZ realises there’s a compelling need to assess the role that ponds play in successfully managing waterfowl.

Ponds have been established across the New Zealand landscape for  various purposes including stock watering, irrigation, storm water  capture, effluent ponding, waterfowl habitat and simple aesthetic values. Currently, there’s little scientific information on what, and how big a role these ponds play as habitat for waterfowl populations.

The aim of this ‘citizen science’ project is to determine what pond habitat features provide good breeding for waterfowl, and promote good pond management practices for breeding these birds. Fish & Game has launched an appeal for people who want to monitor waterfowl  populations on ponds around their area. The aim is to establish a network of ponds to be closely monitored over the breeding season.

You don’t have to be a scientist! All volunteers will be given a set of simple instructions on how to go about monitoring. Fish & Game will supply a manual with simple instructions on how to run their surveys – so everyone round the country is tackling the project the same way, and volunteers gather the best data possible.

If you’re keen to help with collection of data and are prepared to monitor a pond, a fun and fulfilling project that will help New Zealand’s waterfowl and other native water dependant birds, this project is for you. Don’t forget – we are keen to hear from a wide range of people,  including youngsters. Kids – depending on your age, you may need to line up support from mum and dad, a friend or relation.

Your help in this project will not only provide data to drive management decisions, but will give waterfowl enthusiasts, hunters and landowners a unique opportunity to get involved and make a real hands on  contribution to our efforts to manage waterfowl – and keep their numbers up!


To get involved please contact: This email address is being protected from spambots. You need JavaScript enabled to view it.
Nathan Burkepile, Fish and Game Officer, Northland Fish and Game
Published in Issue 158
Sunday, 31 March 2019 21:35

DU director takes up DOC role

DU director and bittern expert Emma Williams’ workload has become a whole lot busier after she was appointed science advisor (wetland birds) for the Department of Conservation in October.

A fulltime job for four years, her main task is to deliver the national bittern research plan. The role also involves work with other wetland birds such as spotless crakes and marsh crakes with the aim of setting up new collaborations with organisations to try to fill some of the knowledge gaps about cryptic and native wetland birds.

Projects include working with Stephen Hartley and students at Victoria University in Wairarapa Moana. One of the current projects involves putting out artificial bittern nests in several study sites, including Wairio, to determine what predators are targeting bitterns.

Emma says new bittern monitoring projects in South Kaipara, Auckland region, Tauranga and Turangi are expanding DOC’s national monitoring reach. The goal is to identify where bittern strongholds and hot spots are and inform where new projects are needed to try to reverse bittern declines.

Published in Issue 176
Sunday, 20 January 2019 16:35

Hunt for the puweto

The spotless crake or puweto is only half the size of a blackbird and extremely shy but Dr Emma Williams and DOC ranger Rose Graham are experts at getting them to reveal themselves. Emma and Rose teamed up this year on a project to monitor spotless crakes in Waikato’s peat lakes Rotomanuka, Ruatuna and Areare where restoration work is being carried out by DOC and Fonterra’s partnership, Living Water.
DOC’s Arawai kakariki restoration programme has been investigating whether the species is a suitable indicator species for wetland restoration. Spotless crakes are thought to be suitable because they have large clutch sizes of up to five eggs – sometimes producing two clutches per season. They’re also very vulnerable, with nests and chicks being easy prey for a range of wetland predators. 
The crakes need specific plants and good water quality for their habitat and food to survive. Theoretically, these specific requirements suggest crake numbers will increase quickly (within a few generations) at any sites that have good predator/weed control and have been restored with the right plantings. As long as wetland restoration efforts cover their home ranges adequately, more crakes should tell you that your restoration efforts have been a success.
Monitoring so far suggests this is true. To date, all three Waikato peat lakes have had three years of management and crake monitoring. During this time, the number of birds detected at listening stations (areas where puweto calls are played) have increased from 11 per cent to 42 per cent of the time. Crakes also rely on habitat that is important for other endangered species, such as the nationally critical Australasian bittern (matuku), suggesting their presence can indicate conditions are good for these species too. 
Spotless crakes are a challenge to work with though. Many crake and rail species are difficult to sex as males and females often look similar puweto are no exception. So little is known about the species, even attempts to sex them using their DNA is a challenge. This is because there is no baseline information to confirm which DNA testing methods are most appropriate to use. Unless you have a known male and female to test your DNA methods on, then you can’t tell whether the results you get are true or not. 
To help with this, Arawai kakariki and Massey University are taking DNA samples from dead crakes found in museums or DOC freezers. The sex of these samples is known because internally the reproductive organs of male and female birds are distinct, and this information is recorded during the autopsy. The DNA test results from these samples can then be used to interpret DNA results taken from the live crakes captured in 2017 and 2018.
To monitor crakes, observers sit out and listened for 10 minutes at each station, three times each summer, in the morning or early evening. Each observer plays local puweto calls intermittently and records any sightings or sounds  heard. They are shy so are rarely seen during surveys but are often heard calling back in response to calls.
To radio-track the crakes, Emma and Rose first had to catch them. To do this they trialled cage traps and a hinaki-type net (also known as a fyke net).
The net is usually suspended in water to catch fish. It has a series of funnelshaped openings, which makes it hard for fish or birds to escape.
However, to catch puweto on land, the net must be properly suspended above the water by using twisty ties, string, and stakes. Placed in naturally occurring tunnels among the raupo, and channelled with weed matting, this style of trap has  proven the most successful to date,  having caught four so far.
Once a bird has been caught, Emma  bands it and attaches a transmitter to the bird’s back. They are so small that only tiny transmitters (the size of a jelly-bean) can be used – each lasting been four to seven weeks, and weighing less than a gram. Once the transmitter is attached, the bird can be released. 
After that, Rose and Mark Lammas use the signal from the transmitter to refind birds. They follow each bird carefully for three hours a day in all weather conditions every day until the battery life on the transmitter has expired. To refind birds, Rose and Mark listen to the signal produced by the transmitter  using a hand-held radio antenna. 
Often the tracker gets  within 10 to 15 metres of the bird, which usually stays out of sight in the dense lakeside vegetation. “It would appear one of the survival techniques of crake is that you can be right next to them and never know they are there. They can sneak across  small open spaces without you seeing them at all,” says Rose. 
The project was funded by the Living Water partnership (DOCFonterra).
Transmitters were purchased  by DOC’s Arawai kakariki restoration  fund.


Published in Issue 175
Roof Cams
Two “roof cams”, one on a ‘selfie-stick’ beside, and another built inside an extended grey teal nest box lid showed a myna bird carefully checking the coast was clear, then repeatedly over several weeks trying to add paper, plastic and other litter to cover up the resident grey teals eggs as the duck deposited them each day.

The myna also frequently pulled nesting material from below over the teal eggs to try to bury them so it could take over the box for itself. Once the teal began sitting on the eggs full-time to incubate them, the myna gave up and the teal eventually successfully hatched the whole clutch. Game cameras have invisible infra-red capability and this can tell us what is happening at any hour of the day or night at times and places we could previously only speculate about.

This same problem also exists in the US where wood duck nest box complexes can get taken over by introduced starlings. Researchers have tried all manner of deterrents including mirrors inside the nest boxes and even flashing lights. Neither seems to dissuade the starlings from displacing the wood ducks. Starlings cover up duck eggs with fine grass and similar material. However starlings like to nest in a dark corner of the box. Cutting a 100x100mm hole in the lid and adding a diffuser skylight that transmits 80-89% of light thwarted this desire by lighting up the nest box corners too. The wood ducks however don’t seem to mind this new accessory. This is now being trialled in NZ to see if myna birds are similarly deterred and grey teal not.

When starlings adopt a wood duck nest box, they intimidate and even attack the resident wood duck trying to get back in. Another successful ruse used to defeat the starlings is to use their own biology to best advantage.
Starlings that are nesting will defend the immediate area around them from other starlings. So US researchers placed a smaller and more desirable, (to starlings), starling nest box onto the larger wood duck nest box. The starlings chose this in preference then kept away other starlings from the wood duck nest box too, but not the wood ducks themselves.

This has also been trialled in NZ with native grey teal and our own introduced starlings. Lacking a proper study it might be premature to call it a success, but starlings have certainly used the smaller starling boxes and when they do they have not been found inside the larger teal box. However on one occasion the two species shared the same plain nest box and, a bit like cats trying to avoid fight perhaps, they each looked and faced the other way as they incubated side by side, the starling in the corner, the teal in the middle.

Roof cam
The “roof cam” inside the afore mentioned teal box took no less than 7,587 photos of a wriggly restless grey teal which suggests that the myna bird may have left more than just rubbish. Both mynas and starlings are host to bird mites. As many as 5000 of these can infest a nest box and come out at night to suck the birds blood. Pulling back the nesting material will reveal a grey mass of eggs in corners and the mites themselves will live in creaks in the structure.

The latter can be avoided at box building time by putting PVA glue in all the joints. About $30 worth of quaternary ammonia will make up 32-litres and this actually dissolves the mites if any are present. So this might be a useful thing to do when servicing nest boxes, (they need old nesting material removed and new added each year. (This also, incidentally, stops parasite build up in the nest).
However the extent to which mites are a problem to box nesting ducks remains to be seen. One simple technique used for establishing if mites were present in a NZ study of starling nest box use was to leave a hand on the nest for 5 seconds and then inspect - and then brush them off smartly if there were! Starling nest boxes with entry holes 42mm in diameter will let in starlings but not mynas. Myna birds need a 70mm diameter entrance hole. So it would be easy enough to study the effects of added nest boxes for either species, comparing the adjoining grey teal nest box use with and without. Likewise testing skylights.

Sounds like a great MSc study to me as grey teal do not readily desert nests so obtaining data should be straight forward. When grey teal nest boxes are serviced each year in March/April, the sheer amount of rubbish left in them by mynas and to a lessor extent starlings is hard to credit and often more than one clutch of grey teal eggs lies buried somewhere in the middle.

So sorting out starling and myna problems can potentially make grey teal nest box complexes even more productive than currently.

A new article on best practice for grey teal nest box construction and maintenance has recently been added to the NZ Fish & Game website.

By John Dyer,
Auckland/Waikato Fish & Game Council
Published in Issue 174