The elimination strategy hasn't worked. In 20 years, the cullers have shot perhaps 10% of the deer. It's time to up the ante.

By the early fifties, it's become apparent that the deer elimination strategy isn't working. One report estimates that in 20 years the cullers have shot just 10% of the deer.

So, in 1956, the well-funded Forest Service takes over the deer control programme building a network of huts (the basis of today's backcountry huts) and wire bridges across rivers.

Now, in theory, a hunter is never more than four hours walk away from a basic hut with bunks, a fireplace, billies, and often a food cupboard. Trial airdrops of food are carried out, not always successfully. Kea get into some while others land in the river or on tree tops.

However, successful drops provide a greater variety of tinned foods and basics, no longer having to be carried in on the cullers' backs. Some shooters explain how they're forced to live off just the deer they shoot when floods cut off their airdropped food supply. Others tell of coping with injuries or isolation, with some becoming virtual recluses.

Yet with the new huts, better food, some tracks and some wire bridges, hopes are now high that cullers can make more of a dent in the deer population.

Go to this episode on rnz.co.nz for more details