Contraceptive injections are being given to Kaimanawa wild horses to curb herd growth and take pressure off the rehoming programme.
Musters have been held every one or two years to keep numbers in check with hundreds of horses being found suitable owners - but that created an enormous workload for the volunteers and the Department of Conservation.
But the Animal Ethics Committee recently approved the use of an injectable contraceptive and already about 60 mares have been given it.
Sue Rivers from Kaimanawa Heritage Horses Welfare Trust talks to Lisa Owen.
