Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 

Pest-free exclosure more prison than paradise

Pest-free exclosure more prison than paradise for rats

Click for big version

Research in which rats were released into a pest-free area has shown they pose less of a threat than first thought.

Ship rats fitted with transmitters were released into a 65 hectare area on Maungatautari near Cambridge during April to September. The area is surrounded by a pest exclusion fence that keeps mammalian predators out, but not in. Once the entire mountain is made pest-free, the area will become part of a 3400 hectare sanctuary planned by the Maungatautari Ecological Island Trust. Landcare Research scientists aimed to find out how rats would behave if they invaded the area, to help design the best defence systems.

Six male rats were caught near the perimeter fence and released inside the sanctuary, one at a time. Only male rats were selected, to prevent breeding.

Four rats climbed back out over the fence, two within 24 hours. The remaining two stayed close to the release point for 3 days, often running around the top of the fence. They then wandered over increasing distances inside the cell. Both were eventually poisoned (after 8 and 28 days).

Landcare Research scientist John Innes says the sanctuary was not exactly a candy store for the rats.

“We thought they would be busting to get in, because there’s ample food and no predators, and that once they did get in, they’d be hard to catch, and do a great deal of damage.

“But in fact, the rats apparently did not want to be there. They would have had to find new den sites and feeding places, and they had no social contacts.”

Mr Innes says although the fences are effective, pests can still invade via trees falling over near the fence, floods or vandalism. However, the research has turned up several key findings for sanctuary managers to combat any rat-related risk.

“We recommend that the Trust place traps on the rim of the fence top as well as inside the exclosure. Also, the knowledge that any rats invading the exclosure first linger within scent of home provides a window of opportunity to catch them when they first arrive.

“After 3 days rats move quite large distances, much larger than their usual territorial range. This is an important clue as to how rats behave at low population densities.

“Given the large distances they cover, male and female rats in that situation could probably find each other quite easily and establish a new population, so it really is important to catch them early.”

Maungatautari Ecological Island Trust Chief Executive Jim Mylchreest says the information gained is of vital importance in managing the project, as it provides factual information to establish the search area and ship rat detection techniques required after a fence breach occurs.

ENDS

© Scoop Media

 
 
 
Business Headlines | Sci-Tech Headlines

 


Serious Fraud Office: Commences Enquiries Into Allegations Of COVID-19 Wage Subsidy Fraud
The Serious Fraud Office has commenced a number of enquiries into alleged abuse of the Government’s COVID-19 Wage Subsidy. Director Julie Read said the allegations relate to multiple complex cases of potential fraud that have been referred to the agency following extensive investigations ... More>>



Environment: Preliminary Environmental Data On New Zealand’s Air Quality Released Today

The Ministry for the Environment and Stats NZ have published the Our air 2021: preliminary data release today. We are currently working to revise the Our air 2021 report to incorporate analysis of the World Health Organization (WHO) 2021 air quality guidelines that were released on 23 September 2021... More>>


Statistics: Food Prices Rise For Sixth Consecutive Month
Food prices rose 0.5 percent in September 2021 compared with August 2021, mainly influenced by higher prices for grocery food and meat, poultry, and fish, Stats NZ said today. September’s movement is the sixth consecutive monthly rise. After adjusting for seasonality, prices rose 0.9 percent... More>>



Reserve Bank: Robust Balance Sheets Yield Faster Economic Recovery

Stronger balance sheets for households, businesses, financial institutions and the government going into the pandemic contributed towards maintaining a sound financial system and yielding a faster economic recovery than following previous deep recessions... More>>


Transpower: Releases Independent Report Into Events Of August 9
Transpower’s Chief Executive Alison Andrew has today released an independent report into the grid emergency of August 9 when insufficient generation was available to meet demand, leading to some customers being disconnected... More>>

Bayleys: Latest Lockdown Adds Further Fuel To Industrial Property Market

The recent construction shutdown resulting from Auckland’s Covid 19’s lockdown restrictions has put additional pressure on an industrial property market that is already struggling to keep pace with demand... More>>