Although perhaps not as jolting as an alarm clock, a cat’s “soliciting purr” can still pry its owner from sleep. And, when sufficiently annoying, the sound may actually coerce them from bed to fill a food bowl.



This particular meow mix—an embedding of her cat’s high-frequency natural cry within a more pleasant, low-frequency purr—often awakens Karen McComb, a behavioral ecologist at the University of Sussex in the U.K. and lead author of a paper about that sound published today in Current Biology.



“Solicitation purring is probably more acceptable to humans than overt meowing, which is likely to get cats ejected from the bedroom,” McComb said in a statement.



To understand just how cats vocally manipulate owners, including herself, McComb and her team set up a series of experiments. First they recorded the purrs of 10 cats; some were recorded when a cat was actively soliciting food and others in a non-solicitation setting. Fifty people then listened to the sounds at the same volume. Individuals judged pleading purrs as more urgent and less pleasant than normal purrs. When the researchers played the purrs re-synthesized to exclude the hungry cries, leaving all else the same, the volunteers perceived the purrs as far less urgent.



McComb suggests that cats may be cashing in on human's naturally nurturing response to a baby’s cry. Previous studies have shown the cat’s embedded cry shares a similar frequency.



Like babies, domestic cats are “completely dependent on us for their survival,” says C. A. Tony Buffington, a professor of veterinary medicine at The Ohio State University, who was not involved in the study. “Any time an animal is in that situation, they are going to be scrutinizing their caregivers for any response to any signal they are sending out. Whatever works, they’re going to do it—whether that’s changing a purr, or doing figure eights between their owner's feet.”



Buffington sees potential in applying the findings at his veterinary hospital to decipher what a cat is experiencing and what it needs. “Here’s something that everyone’s probably observed, but no one has paid attention to,” Buffington says. “Now, we can look at it in much deeper way.”



Photo by Andres Rueda via Flickr