Every three months a contractor employed by ES completes a round of monitoring by tracking tunnels. The contractor secures an inked cardboard strip into each tunnel. A dab of peanut butter is placed at each end. These are left in the tunnel over one fine night and collected the next day. Any pest running through the tunnel will leave inky footprints on the strip of card. These cards are examined and foot prints counted by a qualified operator.
Each tracking tunnel line consists of ten tunnels placed at 50m intervals. We have six of these lines, they remain in the same place permanently. So if one tunnel out of ten shows rat foot prints that is a 10% result for that line. If nine tunnels show rat foot prints that is a 90% result and so on. All six lines are added together and an average is calculated to give a result for the whole block.
Results can vary seasonally or sometimes for no apparent reason but they do give an indication of population trends and therefore the effectiveness of our pest control work.
If we had the man power we could use the tracking tunnels on a monthly or even fortnightly basis. This would give us a much more accurate and up to date picture of population trends, allowing us to concentrate pest control in specified areas.
For three non consecutive days in Dec of each year, an experienced person stops at predesignated points within the DOC reserve and listens to bird calls for five minutes. They record the number and species of birds that they hear. This has been happening for a decade.
This method shows annually trends but is only an indicator. Birds are highly mobile creatures they fly wherever they please. Sometime our bush is full of their song other times it is not. Recent (2020) bird counts show a marked increase in the numbers of Red Crested Kakariki. This is confirmed by our ongoing observations. These birds are relatively rare so this is a pleasing result.
The bird count is funded by ES.
For those of us working on the project, living or spending time here, we see trends emerging. This summer (2020-2021) we are seeing flocks of up to twenty Kereru here. We are seeing and hearing larger groups of Kakariki in the reserves.
We are hoping to expand on our Chirp network as described.
As development of Chirp continues we expect it to be an accurate measure of kill numbers this will provide data and show us areas that need extra traps. We can then shift them to where they are needed most.