Rats get the shove at Rotopounamu
Date: 27 February 2008
Rats at Rotopounamu, a popular area of Tongariro National Park just south of Turangi, are less of a threat to native birds according to the latest monitoring results.
In January volunteers from the Tongariro Natural History Society, with support from staff at DOC's Turangi Taupo Area office, deployed a series of tracking tunnels around Rotopounamu on Mt Pihanga. Their aim was to assess the effectiveness of an Animal Health Board funded aerial pellet 1080 operation that had been carried out in November to prevent the spread of bovine TB.
"Rotopounamu rat numbers are at 4% which is a great result," says Angela Paget, a DOC biodiversity ranger based in Turangi. "The aim is to reduce the rat tracking index to 5% because at this level there is a successful breeding of vulnerable bird species."
Tracking tunnels are set at 50 metre intervals and results are recorded after one night. Results are expressed as a percentage of tracking. This means that if 50 tunnels are used and ten show rat tracks the result would be 20% tracking.
Tracking tunnels are a tool used to determine the density of small animals, such as rats, which can decimate native bird populations, particularly during their vulnerable breeding season. An ink pad in the middle of the tracking tunnel means that when small animals go through the tunnel they leave tell-tale prints at the other end, much the same as someone wearing muddy boots on a clean floor.
Ms Paget says that although tracking tunnels don't give an exact number of animals present at any site, they provide a useful indication of population levels.
"Ecosystems are extremely complex. Changes to any single component always lead to a number of other changes within the ecosystem - this can make ecosystem management a tricky business," she says.
The Mt Pihanga/Rotopounamu restoration project is a community focussed project set up to protect the native biodiversity of this area of Tongariro National Park. ENDS