A team of scientists have completed the largest ever quantitative study of wolf howling using computer algorithms. The findings uncovered 21 different howl types or “dialects” with each species having its own distinctive use of various howl types.
Results show that each species and subspecies have their own distinctive repertoire of howling types, revealing a kind of vocal fingerprint. Different howling types are used with varying regularity depending on the species. The findings were published in the journal Behavioural Processes.
Scientists gathered recorded howls from around the world, in both captive and wild animals, thanks to cooperative efforts from scientists in the United Kingdom, United States, Spain and India. The team, who was lead by Dr. Arik Kershenbaum from the University of Cambridge, built a database of approximately 6,000 howls, which was eventually cut down to the best 2,000 for the study. Not only did they ask zoologists and biologists for howls, they also searched YouTube videos.
Machine learning algorithms then identified the 21 distinctive howl types from the group of 2000. The data also allowed researchers to uncover different repertoires of howling types and there usage for each species. The study examined the howls of 13 “canid” species.
Despite the results, researchers still know very little about the meaning behind each type of howl and what they’re trying to communicate. Like dolphins, wolves are one of the smartest and most social animals on Earth – and they are almost impossible to track and study for long periods of time in the wild.
“You don’t observe natural wolf behaviour in zoos, only in the wild, and you need to know where the animals are when howling before you can really begin to try and discern meanings. But, as with dolphin pods, physically following a wild wolf pack is virtually impossible,” said Kershenbaum.
“As well as being intelligent and cooperative species, wolves and dolphins have remarkably similar vocal characteristics. If you slow a dolphin whistle down about 30 times it sounds just like a wolf howl, something I often do in my lectures.”
“We are currently working on research in Yellowstone National Park in the US using multiple recording devices and triangulation technology to try and pick up howl sounds and location. In this way we might be able to tell whether certain calls relate to distance communication or pack warnings, for example.”
“The presence of complex referential communication in species that must communicate to survive was probably a crucial step in the evolution of language. I think we can shed a lot of light on early evolution of our own use of language by studying the vocalization of animals that are socially and behaviourally similar to us, if not necessarily taxonomically closely related.”