Coyotes and wolves are canids, sharing a common ancestor, but a new study examining their calls sheds new light on the history of interbreeding between the two varieties of animals. Candids are a family of animals which includes dogs, wolves, and jackals.
University of Cambridge researchers examined more than 2,000 howls produced by 13 species in the group, categorizing the sounds by 21 distinct vocal qualities, producing a "vocal fingerprints" for each type of animal.
Investigators found each species utilized distinctive styles of calls, and even subspecies of wolves have distinct vocal fingerprints.
Coywolves, hybrids of coyotes and wolves, are seeing a population explosion, particularly in the eastern half of North America. These canids are sometimes known as eastern coyotes. In the northeastern region of the continent, they are often referred to simply as coyotes.
Researchers discovered that wolves and coyotes were most likely to interbreed with companions who displayed similar howls. Red wolves were found to produce a high-pitched howl, similar to that of coyotes.
"The survival of red wolves in the wild is threatened by interbreeding with coyotes, and we found that the howling behaviour of the two species is very similar. This may be one reason why they are so likely to mate with each other, and perhaps we can take advantage of the subtle differences in howling behaviour we have now discovered to keep the populations apart," Arik Kershenbaum of the University of Cambridge, lead researcher on the study, said.
Study of the howling patterns of wolves and coyotes might also help shed light on the evolution of human speech. The vocal styles of humans are significantly more complex than those of even our closest living relatives, including chimpanzees. By studying the vocalization patterns of different species of animals, researchers are able determine data concerning the genetic history of the animals. The team even scoured YouTube for videos of domestic dogs howling, in order to collect sounds. The 6,000 samples collected included both wild and domestic animals.
Coywolves did not exist in any significant numbers until just about a century ago. Now, a rapid rise in the population of the animals has resulted in millions of the creatures spread throughout half a continent. Around 10 percent of the DNA of coywolves is from dogs, allowing the hybrids to thrive near urban environments.
Red wolves were hunted to the edge of extinction in the middle of the 20th Century, and a repopulation program was halted, in part, due to the large number of wolves mating with wild coyotes.
In Yellowstone Park, conservationists are recording howls of canids around the refuge, in an effort to better understand how population levels are changing over time.
Learning to identify the species of a particular canid by the sound of the animal's howl could also assist in conservation efforts. Once it is possible to reliably recreate howls used to mark territory, the artificial calls could be used to steer wild populations of animals away from farmland and other undesireable areas.
Examination of the calls of canids, and analysis of what the findings can tell us about the hybridization of coyotes and wolves was published in the journal Behavioural Processes.
Photo: Jitze Couperus | Flickr
