At night, somewhere in the wet subalpine scrub of northwest Nelson or the Paparoa Range, a large bird moves through the dark. Its face is pressed to the ground. It is not lost. It is hunting by smell. This is an unusual career choice for a bird. But the great spotted kiwi committed to this direction a very long time ago. It shows no signs of reconsidering. The forest floor is its domain. The air above is irrelevant. Roroa is the largest of New Zealand's five kiwi species. This distinction comes with a bill to match. The bill is long and ivory-pale. It carries the nostrils at its tip rather than its base. This anatomical decision raises questions until you understand the truth. It is a precision instrument. It detects earthworms through several centimetres of soil. The eyes are small. They are largely decorative. Eyesight is not the point here. Smell is everything. The bird trusts its nose more than its sight. It has to. On the ground, it moves with purposeful energy. It seems slightly aggrieved. It has decided the whole arrangement is reasonable enough. By day it retreats into a burrow. Sometimes it shares this space with a long-term partner. Roroa are monogamous. They are territorial. Their behaviour suggests a genuine investment in the arrangement. Pairs hold large territories. They defend them with a call that carries a long way through mountain forest after dark. The male emits a rapid ascending whistle. The female responds with a slower, lower trill. If you have walked the Heaphy Track at night and heard something urgent in the scrub, this was probably the source. The sound is distinctive. It does not blend in. The egg is the other thing worth remarking on. A female roroa produces a single egg. It can reach up to a quarter of her own body weight. This is a physiological commitment so extreme it sounds like a rounding error. She then largely hands it to the male. He incubates it for up to 85 days. Both parents share duties in the later stages. The chick, when it finally arrives, is immediately independent. It must begin foraging for itself within days. But independent does not mean safe. In a mast year, beech seeds flood the forest floor. Rat populations surge. Stoat numbers follow close behind. Most chicks do not survive their first year. The odds are stacked. The struggle is real. The rugged, wet, high-altitude terrain roroa prefers offers some natural insulation against predator pressure. This is why the species has fared better than most kiwi. But better is relative. Around 14,000 remain across four genetically distinct populations. The number edges down by roughly 1.6 per cent each year. At that rate, projections are not comfortable reading. Predator control keeps the trajectory from worsening faster. Specifically, the suppression of stoats across large areas during mast years. The roroa continues, for now. People are doing a great deal of work to ensure that it can.