Monitoring Results and Next Steps
We’ve recently ramped up our monitoring efforts in Tamahere, and the June 2024 findings have been really illuminating. Here’s a snapshot of what we’ve learned and where we’re headed next.
Tamahere Quarry Reserve (Mangaone Stream)
We've been running a weekly volunteer trapline in this 4HA reserve, targeting possums, rats, mice, and mustelids, for the last two years, and our trap numbers show a steady influx of rodents every month or so. This busy public reserve faces ongoing dumping and littering, which attracts rats. Pest control had also temporarily stopped on a neighbouring gully property recently, adding to our challenge.
Most authorities suggest that, to give native bird and bat species a chance, we need to keep rat tracking rates below 5%. So if we put out 20 inked cards in our tracking tunnels for one night, we are looking to get prints in only one tunnel (or none). For rats, it is well known this is hard to achieve with trapping alone.
Monitoring RTI Results June 2024:
Rats: inked card RTI of 20% (target is less than 5% during nesting season)
Mice: RTI of 50%
Insects: 0%
We also trapped a weasel in a DOC200, correlating with high mice numbers. While we’ve had success in trapping a spate of possums in early June and then no bites on the monitoring wax tags, we’ve had re-invasion since last month’s monitoring, with possums recently spotted on our trail cameras.
Rodent Prints: Evidence of Rat and Mice Activity in Tamahere Reserve
Private Gully (Mangaharakeke stream)
This private section of the Mangaharakeke Stream gully system, extending for almost one kilometer downstream from the Allan Turner Bridge, has several local residents actively involved in ongoing pest control and gully restoration. Access to this area is by permission only. It was included in our recent monitoring survey for comparison with our public reserve trapping efforts.
RTI results
Rats: 10%
Mice: 20%
Insects: 30%
Possum numbers are low too, based on camera footage and wax tags. While a few possum incursions continue, the rat numbers are encouragingly low, even though not all gully neighbours are actively involved in pest control yet. Also, 30% of inked cards showed ground wētā, which is a positive sign.
Ground Wētā Tracks: encouraging signs of ecosystem health in the Mangaharakeke Gully
Waikato DC Bilsthorpe Lane Esplanade (Mangaharakeke stream)
Our gully pest control activities along this esplanade strip are temporarily on hold due to extensive vegetation clearance and ongoing new planting. The removal of a large area of gully habitat and food sources explains the temporarily low rodent levels.
RTI results:
Rats: 0%
Mice: 20%
Insects: 10%
However, there’s still significant possum activity noted on nearby wax tags, with incursions coming from nearby un-trapped bush areas.
Key Takeaways
Our monitoring has shown mixed results. Gully areas with higher community involvement in pest control, like the private gully sections mentioned above, and also the Tamahere Eventide private gully and its neighouring properties, have lower rodent activity and positive indicators like ground wētā. However, public access areas with inconsistent pest control on neighbouring properties and affected by rubbish tipping have higher rat numbers, highlighting the need for more intensive efforts.
Moving Forward
We need to address ongoing possum incursions and achieve our target RTI of less than 5% for rats in key areas, especially during the nesting/breeding season.
Increase Community Involvement: Encouraging more neighbour involvement in pest control will help replicate the successes seen in other private gully areas.
Targeted Pulse Baiting: We are discussing the implementation of targeted pulse (intermittent) baiting for rats in public reserves with the Waikato District Council to help reduce rat numbers more effectively, especially around areas with rubbish tipping.
Continuous Monitoring: We’ll keep a close eye on trap results and adapt our strategies based on the data. Much still to be done!
