The threat of Kaimanawa horses
Renunculus recens
(Moawhango buttercup)
What impacts are feral horses causing?
At the time of the 1997 muster, the horse population was estimated at about 1700. This number of horses took a heavy toll on the environment through grazing and trampling. Fragile and unique wetlands and tussocklands and many special plants were under threat. Much of the area where the horses live has not been farmed for decades or ever converted to pasture. It therefore contains many native plants and plant communities that have now been lost elsewhere.
The area is also geologically and climatically unusual. As a result it has many special plants, including at least 16 species which are threatened. Eleven species are known only in the wild horse range in the North Island. One was discovered in 1996 and others might yet be waiting to be found.
Unlike the horses this environment is unique to New Zealand, being found nowhere else in the world. Managing the horses is just one activity aimed at maintaining this unique landscape.
What about animal welfare?
Horse welfare issues remain paramount. A key objective in the Kaimanawa Wild Horses Plan (1996) is that treatment of the horses is humane and that horses must not suffer undue physical or behavioural trauma.
The essence of ethics (or welfare) is almost always a matter of doing what will have the best consequences, given the existing constraints. On this basis, the ethics of using (or not using) a particular control method depends on what the alternatives are and the consequences of not using any method for controlling the population. For feral animals this may involve significant suffering if no control is practised.
Without natural predators the horse population would continue to increase until they starved. Horses taken from the range in the early musters were in very poor condition. Since the herd was reduced the condition of the horses has improved resulting in more births.