DUNEDIN, New Zealand — Only a keen-eyed observer can spot the rare yellow-eyed penguin in the impenetrable forest hills that hug New Zealand’s South Island beaches.

Native to this region, the birds mostly lurk under a canopy of thick shrubs, trees and branches, dashing for hiding places as soon as a human approaches.

Incredibly shy, the yellow-eyed penguin is truly odd. Measuring about 65 centimeters, or just over two feet tall, with striking yellow eyes and a yellow band across its head, it is the rarest species of penguin, nesting in the forest and returning to it. It is also severely endangered.

Despite various measures deployed in recent years to protect this penguin’s flocks, the outlook remains bleak. On average, only 18 of 100 penguin chicks survive their first year at sea. A decade ago, the population was estimated at 6,000. Today conservationists reckon that only 2,000 yellow-eyed penguins are alive.