New analysis of archived calls of North Atlantic right whales reveals distinctive traits

May 18, 2015, Acoustical Society of America
Surface active group of right whales. Credit: Jenny Tennessen/Syracuse University

Human beings have unique voices—from the deep, resonating bass of James Earl Jones to the raspy melodies sung by Broadway star Carol Channing—and we routinely recognize individuals based solely on the way they sound, for example over the telephone, on a music CD or in an animated film.

The same theory that explains individual differences in human speech has recently been applied to other members of the animal kingdom, including dogs and deer. Now researchers from Syracuse University in New York are working to understand whether individually distinctive vocal characteristics of North Atlantic right could be used to identify and track individuals—a potentially useful tool for studying an that spends much of its life hidden under the water.

In an initial study, the scientists were able to correctly distinguish 13 different individual whales based on a combination of vocal characteristics, including length of the calls and the fundamental and . The team will present their results at the 169th meeting of the Acoustical Society of America, held May 18-22, 2015 in Pittsburgh.

North Atlantic right whales feed on tiny zooplankton in shallow waters off the east coast of the United States and Canada. For centuries whalers hunted the animals, and even after achieving some measures of protection in the 1930s, the population has remained critically endangered. Current estimates put the number of North Atlantic right whales at around 450 individuals.

Right whales make about a half-dozen different types of calls. The Syracuse researchers looked specifically at the characteristics of the "upcall," a vocalization that lasts about 1-2 seconds and rises in frequency from around 100 Hz to 400 Hz, at the low end of frequencies audible to human ears. The upcall is the most commonly produced call among all ages and sexes of right whales. The whales likely use the calls to announce their presence and "touch base" with other whales.

Jessica McCordic, a masters student in the biology department at Syracuse University, along with her advisor, biology professor Susan Parks, analyzed more than a decade of archived acoustic data gathered from suction cup sensors attached to the backs of individual right whales in Cape Cod Bay, off Massachusetts; the Bay of Fundy, in Canada; and along the southeast coast of the United States.

Based on the characteristics that distinguish human voices, McCordic initially thought the emphasized harmonic frequencies of the upcalls, called formants, would best distinguish individual whales.

"What I found was that there actually wasn't much difference in the formants, but one of the variables that came out as most important in discriminating the individuals was the duration of the call," McCordic said.

In the end, the team found that analyzing a combination of variables, including the formant, the duration of the calls, and the rate of the fundamental frequency change, could distinguish between the upcalls of the 13 individual whales identified in the archival data set.

"The analysis classified the whales well above chance levels, so that was really exciting," McCordic said.

McCordic said the next step in the research is to see whether the same analytic approach can tell individual apart in the wild using stationary hydrophones installed across their habitat range—a monitoring technique that could yield valuable data to help protect the endangered species.

Explore further: A few dozen sei whales beached along south Chilean coast

More information: Presentation 1aAB1, "Individually distinctive parameters in the upcall of the North Atlantic right whale" by Jessica A. McCordic and Susan E. Parks, is at 8:30 a.m. on Monday, May 18 in the Rivers room. The abstract can be found by searching for the presentation number here:

Related Stories

Nine whales die after Australia stranding

March 23, 2015

Nine whales died on Monday after stranding themselves against a rocky breakwater on Australia's east coast, with experts working to herd the rest of their group out to sea.

Lone whales shout to overcome noise (w/ Video)

July 7, 2010

Just like people in a bar or other noisy location, North American right whales increase the volume of their calls as environmental noise increases; and just like humans, at a certain point, it may become too costly to continue ...

Recommended for you

Scientists ID another possible threat to orcas: pink salmon

January 19, 2019

Over the years, scientists have identified dams, pollution and vessel noise as causes of the troubling decline of the Pacific Northwest's resident killer whales. Now, they may have found a new and more surprising culprit: ...

Researchers come face to face with huge great white shark

January 18, 2019

Two shark researchers who came face to face with what could be one of the largest great whites ever recorded are using their encounter as an opportunity to push for legislation that would protect sharks in Hawaii.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.