The early days of #CitSciNZ: crowdsourcing stoat data in our national parks (Post 1)

Stoat. Photo: Charlie Marshall_Flickr

This is the first part of a 2-part post about engaging the public in stoat research in 1970s New Zealand. Future posts in the early days of #CitSciNZ series will explore other novel projects investigating e.g., wasps and birds considered novel for their time. 

A few weeks ago, I met with Dr Carolyn (Kim) King, one of NZ’s foremost experts on the ecology of mammalian pest species. She alerted me to a project she developed in the 1970s, working with the public to collect data on stoats in our national parks, and queried whether it was citizen science. The term has been in use for less than a decade here (and we don’t have a nationally recognised, formal definition), but the project has many important citizen science characteristics.

The plagues begin…

Rabbit holes in the arid Central Otago region cause wind erosion and consequent loss of farming productivity. See

In the 1970s, Kim worked at the Department of Scientific and Industrial Research (DSIR). Her focus on understanding population dynamics of stoats and not just developing new methods of control is central to current effective and efficient control policies. In the late 1880’s tens of thousands of stoats, ferrets, stoats and weasels were released to control rabbits, which had reached plague levels denuding landscapes and causing massive erosion. Conservationists fiercely opposed these releases at the time, but were ignored by the Colonial Government. More than a century later, stoats (along with rats and possums), remain one of the top predators of our native fauna. And we still have a rabbit problem.   

The mast years

In 1976 and 1979 our native beeches (Family Nothofagaceae) bore heavy seed loads – these were mast years. The food bonanza typically results in an explosion of rats and mice… and stoats. However, once the seeds are gone, the rodent populations decrease, and stoats instead turn to native birds for their nourishment. Kim explained that:

…if you want to control a population artificially, you first need to know how to control it naturally… I wanted to know how stoat populations work, so that’s what I did for the whole of the 1970s

So, from Dec 1976 – November 1978 Kim enlisted the public to help gather information about stoat ecology across 10 of our national parks. These locations were a strategic choice – they guaranteed a ready flow of public observers, and staffed visitor’s centres where the study could be advertised through posters, pest animal exhibitions and public presentations. Stoat sightings cards could be picked up, filled in and dropped off. As for the ability of the public to identify stoats, Kim highlighted:

You don’t see them every day, so if you do see one, you remember it, and they’re different enough from other animals so you don’t confuse them.

The observations 

Over the 2-year study period 1779 cards were completed, most of which provided useable data. Alarmingly, stoats were seen in all 10 parks. Highly adaptable, they were spotted in nearly all habitats: snowy alpine tops and grassy ridges above the treeline, forest, at (or in) rivers and lakes and at beaches. Being largely unconcerned with human activity, other locations also included rubbish bins, campsites, on roads, under buildings, in hen houses and on lawns. 

Some observations (13%) mentioned prey. Native and exotic birds, rabbits, hares and possums (including roadkill) formed important food sources, although gut analyses carried out by Kim and a colleague also included rubbish bin spoils: newspaper, tinfoil, paper and plastic.

Overall, the cards have given an interestingly different view of the life of stoats compared… with dissecting dead ones. They also tell us something about the attitude toward stoats of many people in New Zealand… a surprising number of observers (17%) tried to kill the stoat they saw.

Observations documented on the cards of interactions between the stoat and its prey along with details on stoat behaviour e.g., ‘fighting’ or ‘playing’ with one another made for compelling reading. Although Kim described some of the observations as meriting publication as field notes, she also noted that few of the observers would think of writing them up.

Carrying stoat traps into the Orua (Manawatu) for protecting the whio (blue duck) – see Photo: Department of Conservation_Flickr

#CitSciNZ now: reframing science, engagement and communication

Technological advances aside, the stoat project would have been designed and delivered differently today. Framing a project as citizen science today means allowing for a much broader set of considerations, particularly around participants’ roles. Project or programme outcomes are often both scientific and social. What is clear, however, is that citizen science is a distinct research method, and one that can complement traditional science.

References and further reading

King, C.M. & Moody, J.E. 1982 The biology of the stoat (Mustela erminea) in the National Parks of New Zealand V. Moult and colour change. A suite of papers in New Zealand Journal of Zoology 9:49-144. Available:

King, C.M. 2019. Invasive Predators in NZ: Disaster on Four Small Paws (e-Book & Hardcover). Available:

King, C.M., Gaukrodger, D.J., & Ritchie, N. (Eds.) 2015. The Drama of Conservation: The History of Pureora Forest, New Zealand. Available:

Grue HE, King CM. 1984. Evaluation of age criteria in New Zealand stoats (Mustela erminea) of known age. NZ Journal of Zoology. 11:437-443.

Demonstration stoat trap on the Kepler Trap Photo: Adam_Flickr


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