Can you tell where someone is from based on how they speak? Not all the time. But, sometimes, regional accents are easy to identify. Someone from London speaks differently than someone from Boston. Someone from Australia sounds distinct from someone who lives in the southern United States.​

Humans are not the only ones to have regional accents. Localized dialects have been reported among European cows, Asian gibbons, and African hyraxes. Dolphins have also been shown to develop distinct patterns of speech depending on where they live. ​

​Scientists doing research with bottlenose dolphins in New Zealand have documented accents in groups of dolphins living on opposite sides of the island. The dolphins in the north have different-sounding whistles from the dolphins in the south. ​

Dolphins are very talkative. They use their language to find food, recognize each other, and coordinate behavior. Dolphins communicate with three different types of sound, but in this study, the scientists focused on whistles. ​

​Dolphin whistles have frequencies between 3,000 and 36,000 Hz. They can last up to four seconds. Generally, dolphins who live in deeper water have lower-sounding whistles. Dolphins living on the coast use higher-frequency sounds.​​

Interestingly, researchers found that the dolphins living in the north of New Zealand have lower whistles even though they live in shallower water. The dolphins in the south have higher frequency whistles although they dive deep. Scientists hypothesize that the southern dolphins are imitating the high-pitched sounds of boats in their popular tourist home.

In addition to the frequency, dolphins in the north and south have different lengths and contours to their whistles. The dolphins in the south have a longer whistle with more ups and downs. The whistles are so different that the researchers could predict which population a whistle came from with ninety percent accuracy.​

Scientists don’t know if dolphins from the north can understand the dolphins from the south. They suspect that the dolphins may have trouble deciphering the meaning of each other’s whistles. This difficulty might keep the populations more isolated, reinforcing their distinct-sounding songs. ​

So, the next time that you meet someone from a different place and have trouble understanding what they are saying, remember the dolphins and know you’re not alone!