Rodent-hunting dogs Occi and Moss and their handler Miriam Ritchie have had a busy season on Department of Conservation reserves.
The team is part of Conservation Dogs New Zealand which has dogs trained to find certain species of wildlife and pests. Some dogs find kiwi, tuatara and brown teal; and others are trained to hunt goats, pigs and deer.
Ms Ritchie travels all over the country with the dogs, which are trained to indicate the presence of rats or mice on rodent-free islands or behind predator-proof fences on the mainland. "It never ceases to surprise me how hard they work and how determined they are. They're the best workmates you could possibly have," said Ms Ritchie. Based at the Whangarei Area Office, the team has been as far south as Stewart Island and as far north as Hen and Chicken Islands in recent weeks.
Trips to the Hauraki Gulf and Hawkes Bay are on the schedule.
"It's definitely the season," Ms Ritchie said. "In late summer and autumn, rodents are on the move as numbers explode after summer breeding. Animals are looking for new food sources and territories, and are willing to take bigger risks to find them."
Rats are likely to jump onto a boat and become accidental passengers transported to off-shore islands. When they sense land, or hear birdsong, they can abandon ship and swim more than 1 kilometre. Rats can be devastating on a pest-free island. Not only do they eat precious food needed for native birds, such as berries, seeds and invertebrates, they also eat eggs, chicks and even adult birds on the nest.
Mice are less destructive but still have a big effect, potentially reaching plague proportions in the absence of predators and out-competing birds for food resources.
Ms Ritchie urges boaties to be extra vigilant at this time of year.