Because of their small stature, harbor seals may make a different sound than imagined.
Is this connected to their vocal abilities or the result of an anatomical adaptation?
An international team has now studied the vocal tracts of harbor seals, which are the same size as their bodies.
This suggested that harbor seals can learn new sounds using their minds rather than their bodies.
Harbor seals' learning in calls
EVA HAMBACH/AFP via Getty Images
The majority of animals make sounds that are proportional to their bodily size. Because a larger animal's vocal tract, the air-filled pipe that makes and screens sounds, is longer, it will sound lower-pitched.
However, harbor seals may not always sound as they seem.
They may sound larger perhaps to impress a rival or smaller perhaps to get attention from their mothers.
According to ScienceDaily, Koen de Reus, a Ph.D. student, and senior scientist Andrea Ravignani from the MPI partnered with researchers from Sealcentre Pieterburen.
The scientists examined the vocal tracts and body size of juvenile harbor seals.
The measurements were collected from 68 dead juvenile seals (up to twelve months old).
The researchers also re-analyzed previously collected harbor seal vocalizations to validate the animals' amazing vocal versatility.
The overall thickness of harbor seal vocal tracts matched to their body size, according to De Reus and Ravignani.
Their vocal abilities have no physical explanation. Rather, the researchers contend that only voice memory can describe why harbor seals may not always sound the same way they appear.
Vocal learners will sound vary depending on their physical size, but their vocal tracts will be the same size.
The results from auditory and anatomic data, as per de Reus, might allow researchers to discover greater vocal learners.
The study of various vocal learners may aid in the discovery of the biological foundation of vocal learning as well as give information on the evolution of complicated communication systems such as speech.
Harbor seals are among the most numerous marine animals in the United States.
They are frequently spotted resting on rocks and beaches along the coast, as well as on floating ice in glacial fjords, with their head and rear flippers lifted in a "banana-like" stance.
Harbor seals were historically pursued by state-funded bounty hunters in Alaska, Washington, Oregon, Massachusetts, and Maine because they have been considered rivals of fishermen.
This hunting campaign came to an end in 1960.
The Marine Mammal Protection Act protects harbor seals, as well as all other marine animals.
NOAA Fisheries has documented 16 harbor seal populations in the United States.
Twelve of such populations are in Alaska, while the remaining four are in California, Oregon-Washington coastal waters, Washington interior waters, and the western North Atlantic.
The Aleutian Islands, Pribilof Islands, Bristol Bay, North Kodiak, South Kodiak, Prince William Sound, Cook Inlet/Shelikof Strait, Glacier Bay/Icy Strait, Lynn Canal/Stephens Passage, Sitka/Chatham Strait, Dixon/Cape Decision, and Clarence Strait stocks are all located in Alaska.
A tiny population of freshwater harbor seals lives in Iliamna Lake in Southcentral Alaska, which is part of the Bristol Bay stock.
