2024 FOCUS
- Measure baseline seedling ratio and faecal pellet indices in other areas of interest across the CNI sika landscape to gauge habitat condition and relative deer abundance. There is no “one size fits all”. Different habitat, stress and hunting pressures exists at a range of levels across the landscape.
- Maintain the downward pressure on the reproductive output of the herd in the Rangitikei Remote Experience Zone (REZ_MU), with a hind focused thermal assisted aerial operation in November.
VEGETATION MONITORING
The Clement’s Mill Road (CLE_MU), Kaweka North (KWN_MU) and Kaimanawa East (KME_MU) Management Units (MU’s) received base line vegetation monitoring this year.
Clement’s Mill Road receives intense recreational hunter pressure year-round resulting in less vegetation impact and improved herd health indicators (skeletal size, reproductive status, condition) in comparison with other locations across the CNI sika range.
The KWN_MU encompasses the Kaweka Mountain Beech Project area were deer management operations ceased in 2017. With poor herd health indicators increasingly observed, the Sika Foundation has concerns around deer abundance the associated impact on the habitat.
Enabled by further funding from DOC a third MU for the year was able to be measured (KME_MU). This captures a more “in between” scenario where a range of hunting pressures exist, with some stress in more isolated parts of the MU.
Management units (MU) scheduled for monitoring 2024 and 2025
DEER MANAGEMENT
Previous operations in the REZ have tested various methods and technology available for reducing female deer densities ranging from ground hunting with indicating dogs, thermal drones, long-range shooting techniques and to aerial (helicopter-based) operations (thermal assisted and conventional).
The most efficient and cost-effective method for maintaining the downward pressure on the hinds and their family groups (who live in discreet home ranges impacting mountain beech habitat) is thermal assisted aerial control. This method is also very effective in areas of mountain beech canopy collapse is occurring (die back).
There have been areas of substantial die back observed in some southern Kaimanawa mountain beech habitat in the REZ and neighbouring Waipakihi valley since 2019. These large areas of die back are naturally occurring and become highly desirable sites for sika deer. Collapsing stems smash down vegetation from the browse tier, increased sunlight and rotting vegetation provides nutrients creating habitat that sika deer favour. Managing sika deer impact, and monitoring forest trajectory at these sites is critical to ensure sika deer impacts are managed and canopy replacement occurs.
In November 2024, 35 hours of thermal assisted aerial control was undertaken across the entire REZ. The Sika foundation contributed one hour of helicopter time to recover carcasses that were logistically retrievable and safe to do so. 14 carcasses were able to be recovered for autopsy, and the meat donation to local iwi and the mince for foodbanks programme.
The 2024 operation removed 275 hinds/yearlings, 42 stags of poor quality, leaving 24 stags of good quality – working towards a more sustainable system, with a better-quality sika hunting resource more in balance with the habitat.
From 2017 to late 2019, 316 deer were removed from the REZ as a part of southern Kaimanawa TB survey. Since 2017; 1405 deer have been removed from the REZ (1089 as a part of SF ADM&R plan).
NOV 2024 thermal capabilities, REZ family group that was removed (top) and a stag that was left (bottom):
SUMMARY
The 2017 to 2019 TB survey provided a baseline sample of 213 hinds from the REZ, showing almost half (48%) of the breeding age hinds were barren and 76% were in average to poor condition.
Autopsy data collected from 195 hinds of breeding age during the 2022 – 2024 deer management operations, show an increase in reproductive rates to 72%, with an average condition score of 2.7 out of 5.
Although herd health improves quickly, habitat health is a far slower process that is dependent on maintaining deer densities at appropriate levels over time.
A good conditioned young REZ Sika stag (Dec 2024)
TECHNICAL REPORTS
The REZ is scheduled for a its first remeasure in 2025, along with baseline monitoring in the neighbouring Waipakihi management unit (WPK_MU), where there is some similar mountain beech die back habitat observed. The Sika Foundation is working with DOC who will construct a technical report in 2025 with the data that has been collected for all MU’s measured over the sika range during the course of the project inclusive of the REZ remeasure.
This will provide valuable insights into the difference of relative deer abundance and response in habitat to management efforts, assisting in management decisions moving forward.
A pulse of red beech and mountain beech
Seedlings in the southern now REZ now surviving the browse tier (Dec 2024)