Calling all stoats - your flight is about to depart

By Peter Russell

Ferrets, stoats and weasels belong to the mustelid family. All have characteristic long, slim bodies, short legs and sharp pointed faces. The colours of all three animals vary, with generally blackish-brown upper bodies and creamy, white underparts (as opposed to a draft version of the 1996 Waikato Regional Pest Management Strategy, which stated that they had .... creamy white underpants!) So, how do you tell naked mustelids apart? One’s ‘weasily distinguished’, the other, ‘stoatally different’...but you’ll need to ferret out the difference for yourself!

To enable a new research project to start in late 2012, Dr Carolyn (Kim) King from the University of Waikato needed to obtain some captive stoats. She had hoped to purchase freshly captured animals from local trappers and contractors, but that proved to be too difficult. She learnt of a study that had just concluded at Landcare Research at Lincoln using captive stoats for behavioural observations. By January 2013 the project had finished and the stoats were no longer needed. Maintaining them in captivity for no specific purpose was becoming expensive so they were about to be euthanased. Fortunately, Kim heard about this before the deed was done.

Kim was especially keen to buy the Lincoln stoats that would otherwise have no future. Landcare Research for their part were willing to hand them over. But then the question arose, how could they be transported from Lincoln to Hamilton? Driving down to collect them and bring them back, two days each way, was out of the question, and not only because of the expense. Imagine turning up at a motel in Picton, asking for overnight accommodation for two adults and ten stoats.

Fortunately, Landcare knew all about this problem and how to deal with it. When they needed stoats they brought them from trappers around the South Island. A system of secure transport had evolved for them. Each stoat was put in a separate metal carry box with one mesh side, a sliding door, lots of bedding and a chunk of rabbit meat. Three of these boxes fitted into one cardboard box, unmistakably labelled “LIVE ANIMALS”.

Landcare had an arrangement with Air New Zealand for transport of these boxes in the same manner as shipping dogs or cats in carry cages. The stoats cannot see out and people cannot see in, and freak out at the notion of such unusual travelling companions. Landcare were willing to box up the stoats and deliver them to Christchurch airport. The only remaining hurdle was that Waikato University was to pay the air fares. However, the University was rigidly required to buy air tickets through a travel agent in Hamilton .... they had never been asked for air tickets for stoats before! They simply didn’t have a box to tick that their computer would recognise or understand.

In the end, Landcare Research paid the fares themselves and claimed back the costs. Reimbursements, the University could handle. Ten e-tickets for un-named, four-footed, furry passengers with aggressive tendencies, no. With thanks to the Lincoln team, the stoats arrived safely, the research work was done and the results duly submitted for publication. Gladly, they did not live happily ever after, ..... along with badger, moley and rat. Their tickets were strictly one-way.

Epilogue: The stoats were studied to further understand their swimming abilities, particularly finding out how far they might be able to swim. They were quickly put to work and ‘invited’ to swim in long water tanks with currents of water set at various speeds. Their swimming actions, body and paw positioning and stamina were observed, measured and filmed to simulate a made up passage to a fictitious, offshore island teeming with native birds. One female swam non-stop for almost 2 hours in a valiant effort. Swimming is natural to stoats, even their paws are partially webbed to get maximum go-forward in water. Interestingly, Waikato University were keen to use real stoats and fit them with radio tracking collars and trial them under real marine conditions. Alas, DOC red tape meant that idea stayed dead in the water, just like the stoats would have been had they looked like getting away.


Exciting new opportunity for biological control of wasps

By Ronny Groenteman, Landcare research, Lincoln

Wasps are now widespread throughout New Zealand and in some habitats they are among the most common insects encountered. As a result, wasps have detrimental impacts on native ecosystems, economic impacts on our primary industries, give rise to human health issues, and cause disruption to recreational activities.

Current control options do not provide satisfactory relief, and biological control is thought to be a useful option to explore. When successful, biological control provides long-term, cost-effective solution, covering large scales and difficult terrains. This is especially important when the pest is as widespread as wasps are in natural habitats that are vast and impractical to cover by more intensive control methods.

Biological control against wasps in New Zealand was attempted in the late 1980s, but the first agents to be introduced either failed to establish, or produced insufficient levels of control. Although there were other potential agents to explore, the programme was abruptly discontinued.

At Landcare Research we have recently been thinking that the time was right for re-visiting the programme for biological control of wasps. Not surprisingly then, we were excited to hear about the serendipitous discovery of a seemingly devastating mite in wasp nests in New Zealand.

The mite was discovered by Dr Bob Brown, at the time a PhD student. Bob was working on chemical ecology of wasps, as part of a collaboration between Auckland University and Plant & Food Research at Lincoln. He was seriously upset when some wasp colonies he collected for his study started collapsing in the lab. When he examined the wasps under a microscope, he discovered they were heavily infested with mites. The mites were not easy to identify, and are likely to be a new, yet un-described species. An association between such mites and Vespula wasps has never been recorded anywhere.

Who are these mites? Where have they come from? How long have they been in New Zealand? Are they widespread? Do they actually harm wasps, or are they simply hitching a ride? Can they cause wasps colonies to collapse out in the wild as they seem to have done in the lab? Do they only use wasps as their host, or can they transfer to other insects (honeybees, bumble bees, native bees)? These are only some of the important questions we need to explore in order to determine if these mites can be suitable biocontrol agents against wasps. Luckily now that Bob had completed his PhD on wasp chemical ecology, he no longer views the mites as a nuisance, and is excited about the opportunity to explore their beneficial potential.

To be able to assess the mite as a biocontrol agent, the recently-formed community group V-BAG (Vespula Biocontrol Action Group) will be applying to MPI’s Sustainable Farming Fund in November 2013. V-BAG is based at the Top of the South, and currently includes mainly conservation and restoration volunteer groups, along with Nelson and Central Otago winegrowers. Soon, we hope to see more industries (forestry, apiarists) and more regions represented. Sustainable Farming Fund provides grants for projects of up to thre years, and we hope to get this project funded to commence in the coming financial year (July 2014).

We are currently seeking to increase the support base for this project. So, if you would like to find out more please get in touch on: (03) 321 9904 or This e-mail address is being protected from spambots. You need JavaScript enabled to view it .


Auckland Biosecurity forum a success

Contributed by Jenny Taylor, The New Zealand Institute of Agricultural and Horticultural Science

The New Zealand Institute of Agricultural and Horticultural Science held a successful Biosecurity Forum at the University of Auckland in early July with an attendance of 113 people from a range of organisations. The mix of speakers and different viewpoints on biosecurity that were presented did expand our understanding of this topic. Interesting that we did not disagree on the importance of biosecurity but yet there is still room to sort out how best we approach it. The forum did meet the aim of bringing different groups together and promoting discussion and we received feedback that as an independent organisation, NZIAHS was playing a useful role here. "

NZIAHS represents over 600 members covering all aspects of the primary sector including crown research institutes, universities, primary industry companies involved with the meat, wool, dairy, fertiliser and horticultural sectors.

More detail will be available at the NIAHS website at:


Something fishy about sheep leg

Questions were asked in Parliament in early September about the testing of a possible animal part which arrived in New Zealand with a shipment of palm kernel feed.

The limb was discovered in May on a Bay of Plenty dairy farm. It was originally identified as most likely being that of a small deer or goat species not present in New Zealand.

By June 26, MPI announced, following DNA testing by Landcare Research, it was confident the leg was from a New Zealand sheep despite of one of the four DNA samples indicating it was from a snapper.

Science team leader at Landcare Research, Lynley Hayes said Landcare Research did not extract the DNA but only tested the material that was sent.
"As you can see from the 99 per cent score, we are confident that that was most likely snapper.”

"How that vial came to be, and was sent to us, is something that we don't know - we just tested what we were given," Ms Hayes said.
Labour spokesman for primary industries, biosecurity and food safety Damien O'Connor, believes human error may have been at play prompting him to bring the matter to the attention of Parliament

Adapted from an article published by Fairfax media on September 3, 2013


Pest seeds spilled

More than 2000 seeds of a feared invasive weed have spilt from the back of a truck making the 40-kilometre journey from Ashburton to Methven.

The seeds of black grass, or meadow foxtail, an invader of winter crops in Britain and Europe, were found in a 16.3-tonne consignment of red fescue grass seed imported from Denmark and were being taken to a containment centre.

But according to the Ministry for Primary Industries, the importer did not follow instructions to keep the load safe.

Now Foundation for Arable Research scientists and ministry, Federated Farmers and Environment Canterbury staff are working to identify where the seed may have spilt.

Black grass is resistant to many herbicides and is difficult to control in several crops. It competes for nutrients, light, water and space, out-competing crops and reducing yields.

However, the ministry believes only a few seeds will germinate.

MPI response manager David Yard said the seeds were "fairly immature".

"There might be three or four germinate in the first year and one or two in the second year."

He estimated 28 kilograms of red fescue had spilt during the trip. Included in that would have been about 2100 black grass seeds – enough to fill an eggcup.

He would not name the importer, who was under investigation, and prosecution was a possibility.

MPI would also be taking up the matter of the contaminated cargo with Danish authorities. The red fescue consignment had been rejected and would shortly be shipped back to Denmark.

The spill had occurred in July, a month after the consignment arrived at Lyttelton. MPI was alerting the public now as a possible germination date approached.

FAR chief executive Nick Pyke said that given the potential economic impact of the weed establishing itself, it was vital all reasonable steps were taken to prevent this.

"Early reporting is vital. Farmers can assist by keeping an eye out for any sign of the pest and if found report it immediately," he said.

The likely period to see the black grass would be November to April. The seed heads are usually reddish-purple in colour, giving the appearance from a distance of black grass.

Information on the plant and a photograph is available at:

Adapted from an article in The Press by John Morgan on September 5, 2013.


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