You have heard it. Almost certainly, if you have spent a night anywhere near New Zealand bush, you know the double call. It is low and clear. It drifts out of the dark. More-pork. Ruru. The same sound rendered two ways. Both are accurate. It is said to be the most common native animal sound heard at night in New Zealand. Most people who know it well have never properly seen the bird making it. The mystery is part of the appeal. The morepork is 26 to 29 centimetres long. It weighs around 175 grams. This is smaller than you probably imagine from the authority of the call. The plumage is dark brown and speckled. Large yellow eyes sit in a facial disc. This disc funnels sound toward ears positioned asymmetrically in the skull. One ear is slightly higher than the other. This allows it to locate prey in three dimensions by sound alone. It can detect rodents or insects hidden under leaf litter without seeing them at all. Its feathers are softened at the edges. This ensures it flies in near-silence. It is not just to approach prey undetected. It is so that the noise of its own wings does not drown out what it is listening for. The mechanics are precise. It eats large insects, small birds, and small mammals. Wētā, huhu beetles, cicadas, and large moths are favoured. It is not the gentle creature of children's books. One observer watched a pair visit the nests of three starlings. These starlings had made the mistake of nesting in the same tree as the owls. The owls ferried seven chicks back to their nest in fifteen minutes. Efficient. Unhurried. Completely businesslike. The predation is effective. The starlings do not recover. In Māori tradition, the ruru was a watchful guardian. It was associated with the spirit world. The familiar double call was a good sign. The high, piercing yelp was less often heard. It was more often remembered. It was an omen of bad news. A morepork seen flying ahead on a path was a protector. One that entered a house signified something else entirely. The same bird delivered two different messages. It depended entirely on what it did. The interpretation was contextual. It is New Zealand's only surviving native owl. The laughing owl was larger and stranger. It went extinct in the early twentieth century. The ruru persists. It lives in native forest, plantation forest, urban parks, and suburban gardens. It needs enough trees and enough dark. Most people will hear it tonight, from somewhere, without thinking much about it. The call floats in through an open window. It disappears into the dark again. The bird itself remains invisible. It turns its head 270 degrees through the night. It listens to everything. It carries on.