Kaimanawa horses

neW tools brought to management oF kaimanaWa horses

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Photo: Amanda Trayes kaiManaWa heriTage hOrSeS SOcieTy

Kaimanawa wild horses, released following immuno-contraceptive treatment Photo: Michelle Clarke

The Kaimanawa wild horses are descended from domestic releases from the late 1800s onward and occupy a large parcel of the Waiouru Military Training Area.

This herd has long had a place in New Zealanders’ hearts, and in 1981 a protected area was established. Horse numbers surged, with overpopulation threatening the fragile ecological balance, as well as the health of the horses. Management since then has involved a number of partners working together to implement an agreed ideal herd number. Most often the public hears about this with the annual or biennial horse musters.

The Kaimanawa horse musters have involved careful monitoring, rounding up horses, and considered rehoming through organisations such as the Kaimanawa Heritage Horses Welfare Society (KHH).

The long-term strategy has been, and remains, to protect both biodiversity values and the health and heritage of the Kaimanawa wild horses.

Changes to the long-term strategy toward managing the wild Kaimanawa herd

The Kaimanawa Wild Horse Muster of 2022 marked the beginning of a new era in Kaimanawa wild horse management with the introduction of an immunocontraception program following the re-homing muster. It is hoped the introduction of this program will assist in the stabilisation of herd numbers and

The range of the Kaimanawa wild horses – blue striped area – showing management zones. Map: DOC

Helicopters muster the horses over large areas and difficult terrain. Photo: Michelle Clarke

help see a decrease in the necessity to conduct annual re-homing musters.

Wild horse management throughout the world has made significant strides in the last decade – developments keenly watched by partners in management of the Kaimanawa herd. With recognition that an alternative method for controlling population growth was necessary, the volunteer team at Kaimanawa Heritage Horses Welfare Society (KHH) have spent the time advocating for the immunecontraceptive method as a complementary option to re-homing.

With resource-intensive musters being held annually or biennially for two decades the need for an alternative option to help reduce re-homing requirements has long been required. The introduction of a controlled immuno-contraception strategy alongside re-homing will start to bring that change. Extensive research and collaboration with overseas experts informed the decision on which drug to implement with the Kaimanawa wild herd, and consultation with members of the Kaimanawa Wild Horse Advisory Group to work through application logistics began several years ago.

There were a range of factors to consider with regard to how to administer the immuno-contraception drug, with minimal interference of the horses being forefront in decisions. Finding a balance between drug efficiency and frequency of application was a priority consideration, along with the number of mares that would need to be treated in order to reduce population increase.

There is no intention of eradicating the horses nor suppressing the breeding ability of all mares remaining in the wild herd. The addition of contraception as an alternative management option will remain alongside re-homing for the foreseeable future until a greater understanding is in place of the effects of

Kaimanawa horses receiving the immuno-contraceptive treatment. Photos: Michelle Clarke

The existing yards, with horses under observation following treatment. Photo: Michelle Clarke contraception on the wild herd and their breeding rate. The ideal scenario would be to reduce the need for re-homing musters to occur annually and instead become the secondary management option that is utilised as and when required to maintain the agreed herd size. As we progress through the coming years, we will be in a better position to understand the effects of the addition of contraception and hope to find a balance that enables re-homing musters to coincide with the subsequent revaccination of previously treated mares. Monitoring of the wild herd will remain in place through aerial surveys, extensive photography programmes and ongoing data collection to ensure the correct approach can be applied in the future.

The focus now shifts towards improving facilities to ensure the contraception option can be utilised in a greater number of horses. The geographical nature and vastness of the area limits the ability to treat horses who live in the areas further away from the existing yards. Horses travelling from these more farreaching areas are usually committed to the one-way journey of re-homing. This is mainly to ensure their welfare is not compromised through issues related to the long-distance travel associated with returning them to their established area of the ranges once treatment is complete.

Once funding can be secured and new yards can be built in the southern end of the management area, the contraception program can be extended, and we can be closer to achieving the goal of reducing the need and frequency of re-homing musters.

To see the addition of contraception as a combined tool toward maintaining a healthy and sustainable wild herd was an exciting achievement and culmination of much work. The committed partnerships between Kaimanawa Heritage Horses Welfare Society (KHH), The Department of Conservation, and the Kaimanawa Wild Horse Advisory Group will remain focused on seeing it applied throughout future years.

The collaborative approach applied to the management of the wild Kaimanawa horses with a willingness from all parties involved to see the best outcome for the herd and their environment has received praise from wild horse groups and advocates from around the world. As we move into the future of Kaimanawa wild horse management, we go forward knowing that the relationships built over the previous years have proven a balance can be found for the benefit of all and with the welfare of the horses paramount in all decisions.

Further information can be found at www.kaimanawaheritagehorses.org

Kaimanawa wild horses being rounded up into the yards. Photo: Michelle Clarke