Imagine this: a chill Halloween night in Western Massachusetts, a cloud cutting across the full moon like a razor. Frost brightens the sky, and the trees in the apple orchards are decrepit, tortured skeletons of their daylight selves, holding the moonlight like a tulle veil. And from just beyond the trees, a howl rises like the fresh dead; a terrible, pipe-organ howl, voices sliding into each other on black-key notes, a chorus of the damned.
It was neither wolves, which have long been banished from New England, nor coyotes. It was the pack of New Guinea Singing Dogs kept at the farm on my college campus. I was a freshman then, the year we sold the Singing Dogs to a zoo because of noise complaints. They were a pet of two professors: one, an expert on canid evolution, and the other, a professor of animal behavior and bioacoustics. The mysterious and rarely-seen New Guinea Singing Dog is a fascinating species that is slowly helping scientists understand one of the most blood-curdling sounds in Animalia, and the reasons behind why, and how, we howl.
The New Guinea Singing Dog is not a distinct species but, like its close cousin the dingo, is likely an ancient and wild breed of the domestic dog, Canis familiaris. Some scientists believe its was brought to Papua New Guinea during the Stone Age, and has lived since then only in the cloud forests atop the highest mountains of the island. However, it’s not 100% certain it was ever domesticated — Canis is an unusually plastic genus in which all species may produce fertile offspring with each other, making their genetic history hard to trace. Whether it was ever exiled from the hearth and abandoned to the wilderness, or was always feral, it is very friendly towards humans — I’ve had my hand licked by one. Singing Dogs are even bred and kept as pets nowadays. But don’t let their easygoing nature around humans fool you: they remain clever, fierce, expert hunters, and can display savage aggression towards each other. I spoke of my college’s NGSD as a “pack,” but they are not believed to be pack animals; the ten dogs were separated by chain link fences to keep them from killing one another. Those fences were also ten feet high, because this collie-sized dog can jump high enough to slam dunk a basketball from a standstill. The original fences were only eight feet high, and on the very first day of their college experience, a female singing dog jumped over it, ran into the pasture, and ripped out a sheep’s throat with its teeth.
It’s that jumping ability, combined with its extremely high intelligence and its incredibly flexible spines and leg joints, that has led researchers to believe that this dog is semi-arboreal. The montane cloud forests of Papua New Guinea are full of felled giants and stout trees with low branches, and the ability to climb trees and jump between them would give it the advantage of being able to raid birds’ nests. The tapetums of its eyes are extraordinarily reflective, giving it a superior night vision which is common to cats and very rare in canids. But what sets it apart from any other animal is its distinctive choral howl.
For the singing dogs at the farm, it would usually start like this: the oldest female would initiate the howl, and often within milliseconds, too close for the human ear to differentiate, the rest would join in perfect harmony. (Click here to listen.) Each dog’s contribution to the group howl lasts 3 to 5 seconds as they braid their voices together like a wreath. The near-simultaneity of the howl is one of its most perplexing aspects, because, as I stated, the dogs are believed to be solitary. Social dogs like wolves or coyotes howl to bond the pack or family group; if one member is lost or separated, a choral howl will unite them. If a hunt is about to begin, a howl will ready them. But because NGSD have never shown much sociability, we do not know for sure how such a beautiful and complex choral howl evolved, or exactly what it’s used for.
Canids are not the only animals that howl. Primates, too, communicate over long distances of forest using choral howling. In Africa, gibbons start their morning by taking a family trip to the highest nearby tree and advertising their presence and numbers with loud and expressive songs. In South America, the howler monkey has evolved to possess an enlarged hyoid bone, giving it the loudest and most powerful voice of any land animal. Its barbaric yawp can carry over three miles, and sends a message to other families and clans: This territory is ours, and our tribe is large enough to defend it. This vocal sabre-rattling helps the monkeys maintain territories large enough to sustain their numbers, while avoiding actual physical conflict.
STOP YELLING AT MEEEEEE!
Could the NGSD’s howl be primarily territorial? Certainly it is used to communicate boundaries, but the complexity of their harmonies suggest that’s not the only reason. There is certainly a sexual aspect to the howl, which we ascertain from the fact that choral howls are always begun by mature females. For an animal that seems, in captivity, either unable or unwilling to cooperate with others of its kind, it seems to have a social hierarchy that is reinforced in song: an “alpha” female acts as the prima donna while other females play second-chair sopranos with a chorus of male altos and tenors. Perhaps individuals are advertising their age and virility to each other in a sexual display while they check each others’ distances. It’s more than likely that these dogs do have some social organization even more complex and nuanced than that of wolves.
But we do not know, and may never know, because New Guinea Singing Dogs have never been studied in the wild. They are too elusive, in their misty mountain forest, and too shy, and too rare: due to the destruction of its forest habitat, the NGSD is the most endangered canid in the world. Even the Papuans who will occasionally kill and eat them say they have never seen them in the jungles, only when they come into the village to steal chickens. But they hear them every night, calling to each other from their mountaintops in an eerie opera of cloud and blood. The howl of the New Guinea Singing Dog is the music of a ghost, one that is vanishing in a dying forest, and some day may never be heard again.