'Monster rats' in Wellington the size of small possums

Monday, 24 June 2019

Conservationists warn some species could be lost in a rat population boom. (First published 18/06/19)

Rats are so huge in Wellington the term 'monster rat' is catching on.

Some rats, up to 50cm long, are shocking Wellington trappers during the mega mast year - forest seeding is higher this year, and rats are enjoying an abundance of sustaining snacks.

Predator Free Wellington director James Willcocks said there had been an increase in rats, and they were big.

'We have received reports of some huge rats being caught which we haven't necessarily noticed previously.'

Ian Robertson of Predator Free Mt Victoria caught this rat a couple of weeks ago. It's 50cm from nose to tail, weighing 500 grams.

* Rat 'invasion' in Auckland as pest control experts report surge

* $30.5 million hit planned for 'mega mast'**

Norway rats were being caught, including one which was the biggest rat he'd ever seen, Willcocks said.

This rat the ''size of a small possum'' was caught in Aro Valley, Wellington, this month.

The higher-than-normal catch rate could be indicative of abundant food sources through the mega mast event, but it also reflected the number of trappers coming on board across Wellington.

In Wellington the term 'monster rat' is being used to share images of chunky catches on social media.

A rat caught in Aro Valley was described as the size of a 'small possum' - typically, adult possums are 65 to 95 centimetres long and weigh 1.5 to 5 kilograms.

But Miramar was different, and Predator Free Wellington's annual chew card operation in Miramar revealed a slight drop in terms of rat abundance from 17 per cent in 2018 to 12 per cent in 2019.

'If people weren't doing this we would have expected rat numbers to have grown substantially in line with international research indicating that rats are becoming more abundant in cities.'

Predator Free Mount Victoria leader Ian Robertson said his largest catch weighed 500 grams and was 50cm long.

The 'absolute monster' was the first Norway rat he'd ever caught in the traps he checked, all the others had been ship rats, he said.

Predator Free Miramar leader Dan Henry said where traps were checked regularly the rats were less than a year old, smaller and cuter.

'The big ones, like Ian's, are the refugees that have been in hiding for many years.'

Forest and Bird spokeswoman Megan Hubscher said the mega mast year was a matter of life and death for native species.

'These mast events are going to become more frequent and that's something we need to be looking at,' she said.