Dolphin research could be crucial to their survival
You wanted to know
"Will scientists ever find out what dolphins are talking about?" asked a young patron at Schaumburg Township District Library's Summer Science program.
Sleek, social and extremely playful, dolphins, also called cetaceans (an order which includes dolphins, whales and porpoises), communicate with a combination of echolocating, whistles, eyesight, hearing and body posturing to draw the pod together for a feast, for fun or to signal danger.
They are extremely smart, according to Rita Stacy, curator of marine mammals at the Brookfield Zoo, where she's in charge of the zoo's pinniped collection, which includes harbor seals and gray seals and dolphins.
"Dolphins are so fascinating; they have individual personalities," Stacey explained, describing a dolphin's signature whistle which is as distinct as a person's name.
"It's an announcement that they've arrived. Scientists are investigating to better understand how and what it means."
The challenge is that they live in water, Stacey said, so it's difficult to isolate the sounds, and sound travels much faster in water. Without visual clues, scientists struggle to understand which dolphin is communicating, how and why.
"Sometimes they let out bubbles when they whistle so we can know who's communicating," she said.
Dolphins whistle when feeding, and a calf and mother dolphin will whistle to each other. Dolphins can repeat another dolphin's signature whistle.
That bump on top of a dolphin's head is called a melon. Located between its nose and blowhole, the inner tissues focus sound and assist in the process of echolocation, the dolphin's call and response sonar communication system.
Sounds produced return at different times to each ear and information is gathered on the time difference. The skull and air sacs around the melon also support echolocation. Toothed whales, dolphins and some bats use echolocation to communicate.
Brookfield Zoo has eight common bottlenose dolphins matched with 10 full-time animal care staff, plus seasonal staff. These gray, sleek mammals have pinkish bellies and unique coloration that make them easy to identify.
Dolphins use pectoral flippers, a dorsal fin and a tail fluke for propulsion, moving their tails up and down to speed through the water unlike fish, which propel themselves by moving their tails side-to-side.
The zoo dolphins all wear Fitbit-like-data tags, what Stacey calls "D" tags, to monitor activity and record sound. Hydrophones installed in the three exhibit pools help researchers recognize the dolphins in each location. Video cameras also supply information.
Stacey describes what researchers might learn by understanding dolphin communication.
"We want to learn as much as possible. Dolphins are a sentinel species in our oceans and we need to know how we affect them, either with sounds or environmental conditions. We're doing a lot of changing to our planet. Ocean temperatures are changing. Learning about communication will let us know how to better survive in this environment. All the research ties together for all animals."
Dolphins have playful body language like pats and eyeball rolls, head wags and hand (fin) holding. Stacey says she's truly enjoyed her 20-plus years working with these animals and facilitating research that can improve conditions in the wild.
People with a bachelor's degree in biology, zoology or psychology can be well-suited for the job, so long as they hold a scuba certification.
Stacey advises, "As stewards of the Earth, we need to find out all we can about the animals on Earth to make sure we are taking good care of them."
Check it out
The Schaumburg Township District Library suggests these titles on dolphins:
• "Everything Dolphins" by Elizabeth Carney
• "Dolphins" by Josh Gregory
• "Dolphins" by Scott Ingram
• "Dolphins and Sharks: A Nonfiction Companion to Dolphins at Daybreak" by Mary Pope Osborne
• "Animal Behavior: Animal Communication" by Stephen Tomecek