Funded by Auckland Zoo Conservation Fund
The Matukituki Valleys have been surveyed by the KCT since January 2016. To date, no nests or breeding activity has been recorded and only one fledgling sighted up until February 2019 when 6 fledglings were caught and banded. The reason for lack of documented breeding activity may be a result of high predator numbers re-invading the area.
Understanding how predators are impacting resident kea and breeding success is crucial for ongoing recruitment in the valley.
As such this project will aim to:
i) ascertain sub adult and adult kea survivorship in the Matukituki Valleys;
ii) monitor kea breeding success in the study area and
iii) understand predator interaction and risk to a population of kea, east of the main divide.
10-11th January 2020
Two days were spent in the Matukituki installing 15 camera traps (seven in the West Matukituki, eight in the East). The camera traps were set up using the same methodology used in the DOC Eastern Forests Project. One more camera is to be set up in the West Matukituki on the next trip, bringing the total to 16. Intentions are to place 16 more cameras in the field (eight more in each valley) next season.
A second January field trip will be conducted towards the end of the month. This will involve mortality checks of the adult kea with transmitters fitted, tracking of potentially nesting birds and catching and attaching more transmitters to adult kea where possible. The 15 installed camera traps will have the SD cards and batteries swapped and the meat removed for this round of monitoring. One more camera will be added to the West Matukituki to bring the total to sixteen.
29 Jan – 1 February 2020
All cat trail cameras had their SD cards swapped and were set to a ‘dry round’ of monitoring in the East and West Matukituki Valleys.
The weather allowed for four catch sessions on Cascade track and three catch sessions at French Ridge Hut. A total of 17 kea were caught on this trip (12 on the Cascade Saddle track and five at French Ridge Hut).
Eight transmitters were fitted to adult kea (five males and three females). Bands were fitted to all birds caught and samples and measurements were recorded for the database.
Next Steps – February – August
- All photos taken on the motion censor trail cameras need to be analysed for presence of cats and other species.
- Another trip to change SD cards is scheduled for the 15th to 17th of February. This will involve placing erayze and rabbit meat in the cages for another ‘meat round’ of monitoring.
- A 1080 drop is scheduled for Sunday 9th February (finishing Monday 10th February with Tuesday 11th as a backup). With 13 transmitter-fitted kea in the drop zones within the West and East Matukituki Valleys, there is an opportunity to monitor kea throughout and after the drop. This requires a number of Sky Ranger flights (one before the drop and two to three after the drop) to monitor kea mortality. Any mortality signals will be tracked on foot to determine their status (dropped transmitter or dead kea). Any mortalities will be taken in for post-mortem.
- Regular foot tracking and aerial flights are to take place throughout the year to check signal status of birds. A requirement for the cat study is that any dead kea are located as soon as possible for an accurate post-mortem.
- From August on, all adult kea can be tracked to locate any nests in the West and East Matukituki Valleys. This will go towards the nest survivorship study.
Monitoring outcomes of study kea through 1080 operation
A 1080 operation was carried out on the 10th-11th February 2020 by Department of Conservation. A skyranger (remote tracking) flight carried out just prior to the drop on the 9th, found 10 of the 13 kea fitted with transmitters in the drop zone. Signals from the other 3 transmitters were not picked up at that time. It was later confirmed that a further 2 kea were within the operation area and 1 kea had chewed off its transmitter prior to the drop taking place (this was recovered at a later date). As such 12 out of the original 13 kea were ultimately confirmed as present and able to be monitored throughout the operation.
Tracking outcomes: A skyranger flight carried out on Thursday 13th Feb found 2 transmitter signals had switched to mortality mode. As a result a person was sent in on the 14th and 15th to track down the signals to recover them to ascertain the birds status (i.e. whether dead or a ditched transmitter). At this time neither transmitter was located however a further 3 mortality signals were picked up. Four birds were confirmed alive at this time.
A full team was sent in during the next fine weather window (19th and 20th Feb) and 6 dead adult kea and 1 dropped transmitter were recovered. Five kea were confirmed alive (either a signal or sighting returned), however a signal could not be found for one female who had previously returned a signal on the 15th Feb. She was finally confirmed alive during an aerial tracking flight on the 18th Feb.
The recovered bodies were sent to Wildbase Hospital and Landcare Research for necropsy and toxicology testing. Results of testing confirm death from 1080 poisoning. All kea had previously been tested for lead and found to have low levels.
Where to from here?
1080 has been shown to benefit kea populations in some areas (particularly remote locations) by suppressing introduced mammals which kill nestlings however, if adult survival through 1080 operations is 56.8 % or lower, the cost is likely to exceed the benefits of increased nest productivity in subsequent years.
So why do some populations, such as the Matukituki Valley kea, seem more at risk to picking up 1080 than others?
At-risk populations may include those kea which are habituated to people (in particular, hut birds and those kea being fed by people), or which have high blood lead levels (which may make them more likely to scrounge due to impaired cognitive function impacting on ability to forage natural food sources). The Matukituki Valley birds fall into this first category. However, there may be other factors that put certain kea at higher risk (time of year, individual behaviour, cultural learning and food availability etc) and until these risk factors are identified, more funding and research needs to be focused to identify robust and cost-effective mitigation measures as well as ongoing monitoring of these populations through operations.
As such, we advocate the following measures urgently be adopted to minimise harm as follows:
- Review all current data to identify what makes a kea population at-risk;
- Identify and research other potential risk factors;
- Review all planned 1080 operations to identify which are likely to have at-risk kea populations.
For populations identified as at risk, operations should be postponed unless:
- Research and mitigation measures are researched and implemented;
- Survivorship is monitored and mitigation efficacy measured.
Trail camera outcomes
Two sets of camera data have been downloaded and are in the process of being viewed and results logged. Results will be posted as soon as they are received.