Gadget is a dog with a job.
The Jack Russell – fox terrier cross is a certified rodent detector dog, and her job is to track down unwanted rats and mice on New Zealand’s conservation islands.
Sandy King has trained 6 ½ year old Gadget since she was a puppy, and she says that the advantage of dogs is their extraordinary sense of small.
”Whereas we can see things, like rodent chewing or droppings, the dog will pick up things that we can't see, just through the scent."
“[The dogs] must wonder sometimes, why on earth we can't detect something which is like an enormous flashing beacon to them,” says Sandy.
A lot of Sandy and Gadget’s work is routine surveillance, confirming that islands have remained rodent-free.
On a recent trip to pest-free Whenua Hou – Codfish Island, for example, Gadget and Sandy had a week to check out as much of the island as they could.
Sandy and Gadget began at the hut, and then widened their search to include areas near where boats moor and where it is most likely a rodent might get ashore.
Sandy says the hut is most likely place to find rodents which might arrive on an island in luggage, as a stowaway on a boat or other vehicle, or by swimming or rafting from the nearby mainland.
“Rats and mice just tend to gravitate towards where people are. Quite often I think they're looking for a place to nest rather than food,” says Sandy.
Sandy says there are definite advantages to having a small dog. The food bill is small, and so is the amount of poop that Sandy has to pick up (and yes, when working on an island like Whenua Hou, Sandy has to collect every piece of dog poop and remove it from the island).
“And she's very easy to transport,” says Sandy. “She sits on my lap in the helicopter or plane … [and] she's really easy just to lift up and put up ahead of me if it's a really steep track, for example. If she was a 30 kilo Labrador, I think I'd be really struggling.”
When Gadget was a pup, Sandy says she would carry her around the house holding her over her head, and get other people to do the same, so Gadget would be relaxed about being lifted and passed from person to person, for example when getting off a boat.
“I taught her to indicate for rats and mice by playing with dead ones that I had caught. I’d tie them to a piece of string and drag it along and … she wanted to chase it and catch it. It's just a big game to start off like that,” says Sandy. Then she would hide the rat and encourage and reward Gadget for searching for it and trying to dig it out.
Sandy says that a food reward always works well with Gadget, who also enjoys a game with her ball as a treat.
As well as training Gadget to identify the smell of rats and mice, Sandy says she had to train the dog to ignore other scents. She says that, of course, the dog smells everything, but the trick is to teach her that other scents are boring.
She uses habituation to teach Gadget to ignore scents.
‘I would take her, and just go and sit there amongst a penguin or seabird colony and eat my lunch,” says Sandy. “And she would have to sit there and be bored.”
Sandy says that “having the dog is a ticket to places that I probably wouldn't be invited to go otherwise.’ The work has taken her – and her dogs – to Campbell Island in the subantarctic, Rangitoto in the Hauraki Gulf to the north, out east to the Chatham Islands and many islands in between.
At home on Stewart Island, Sandy and Gadget can often be seen checking boats down at the wharf, and meeting school groups heading over to Ulva Island for a day trip. She says the dog is a good way to trach people about the importance of biosecurity and preventing pests from reaching islands.
Sandy says that a rodent detector dog alone is not enough.
“The dog is a very useful tool, and it's a tool that can do things that a lot of the other tools can't,” says Sandy. “But it's not the only tool. We need a combination of traps and tracking tunnels, human eyes and vigilance, and the dog's nose to give a place a really thorough going over and ensure that if anything does arrive, we detect that as soon as possible.”
Gadget is one of a growing number of conservation dogs that are specially certified as part of the Department of Conservation’s conservation dogs programme. As well as pest detector dogs, there are species dogs trained to help rangers locate rare birds such as kākāpō, takahē and whio.