Studies of Florida’s Wild Dolphins Reveal Unique Social Feeding Behavior
Barbara Brunnick, Ph.D. Taras Oceanographic Foundation
I have been studying whales and dolphins most of my life. I was a naturalist on whale-watch boats as a teenager, and as an undergraduate, I worked with a team, to get the first underwater film of orcas in the wild. My graduate work involved investigating the social and acoustic behavior of dolphins and my doctoral thesis was based on years exploring the rich social lives dolphins enjoy in the wild. I also spent nearly 30 years performing necropsies to determine the cause of death of stranded dolphins.

I bring all my experience as a Ph.D biologist and behaviorist to my dolphin work everyday. For the last decade, the Taras Oceanographic Foundation, under a general authority of the National Marine Fisheries Service, has been conducting dolphin surveys in Palm Beach County.
Odyssey and her calf forage together along the coast of Palm Beach County. The Taras Oceanographic Foundation of Jupiter focuses on collecting important data concerning bottlenose dolphin abundance, distribution, and behavior in Florida waters.
We position our boat within three miles from shore, and travel at slow speed, until we see dolphins. We will then follow the dolphins long enough to photograph each dolphin and document their behavior.

And although I have studied wild dolphins for decades, I still find new and different behaviors that are remarkable. This year was no exception.

There are days when bait fish seem to fall from the sky. On those special days, when the seas are flat, we watch all kinds of fish jumping out of the water; some high in the air in a single arc, others low and repeatedly as they travel some distance.

Flying fish routinely glide, with ease, for several meters. Ballyhoo and Bonita will jump to avoid being eaten. Every once in awhile, a clever dolphin will take advantage of these jumping fish; a clever dolphin like Odyssey, and her offspring.

During one of our regular surveys, we encountered a resident dolphin we know as Odyssey, and her yearling calf. Apparently, it was time for weaning, and she was conducting a master class in the art of catching fish. And when I say ‘catching fish’ I mean CATCHING fish.

She was throwing a fish into the air, and artfully catching with in her mouth. She demonstrated the process a few times for her calf, and then did something remarkable.
Bottlenosed dolphins hunt baitfish, including this ballyhoo, for food. These fish must be swallowed head-first to avoid potiential injury or death from choking.
She bit off the head of the fish, before throwing the body in the air, for her calf to catch. We could not help but make the comparison of a mother cutting the crust off a sandwich, before serving it to her child. But it is more than that; she was keeping her calf safe.

For the significance of this simple act, we need to first examine the basic anatomy of a fish. Fish use gills to acquire oxygen from the water. These gills are located just at the base of the head. When a fish breathes, it draws in a mouthful of water and pulls the sides of its throat together, forcing the water through the gill openings, which expand away from the body.
To protect her calf from choking, Odyssey carefully removes the head of the fish.
Dolphins do not chew their food. It is imperative, therefore, for a dolphin to swallow their prey, head first.
If a fish were eaten tail first, it might expand its gills while passing through the throat of the dolphin, and become wedged. In all the necropsies I performed, I once found one dolphin with a fish caught in it’s throat. The fish was swallowed tail first, and the result was deadly.
Odyssey subdues and tosses baitfish in the air, then tosses them to her calf prepared to safely eat.
Back to Odyssey and her calf. She was biting the heads off the fish, so her calf would not catch the fish backwards and choke to death. She threw the fish body high in the air, and her calf made repeated attempts to make the catch. More likely motivated by the game than the food, the small dolphin was still nursing and probably not too hungry. Over the next few months, as this calf grows, Odyssey will insist it hunt down its own food. The catching strategies learned now, will be all the more important in the future.
Odyssey’s calf catches fish that she has prepared by skillfully removing the head and gills.
But even the best strategies and the most prepared youngster will not grow to be an adult unless there continues to be the abundance and variety of fish to eat.
We are currently living through the sixth mass extinction event this planet has experienced. In the past, these epic occurrences were the result of volcanic eruptions or asteroids striking the earth, but this time it are our own doing.

Why is it important to study dolphins? Sure they are cute and all, but why should anyone support such endeavors? Because, in many ways, we are alike. Dolphins eat the fish we eat. They raise their kids to be better citizens, and work every day to make a living and support their families. They are the masters of the ocean environment; a subject about which we are remarkably naïve. And the ocean is vital to the survival of us both.

Although we continue to harvest the resources the oceans provide, at un-sustainable rates, we could learn from the marine mammals how to find areas of highest productivity and hunt selectively. As we increase the noise in the ocean with our recreational watercraft, commercial ships and military exercises, we learn from the dolphins that in the deep ocean, it is by listening and hearing we can have the best vision. Marine mammals are the ocean canaries, warning us about the disastrous effects of pollution and habitat destruction, and they can be our guides to find answers, to questions we have not yet thought to ask about the ocean realm.

It is through the long-term studies like this one in Palm Beach, that dolphins teach us about the ocean, the world and ourselves. We just have to keep going to school.

Please support your local wild dolphin research and conservation team. Make a tax deductible donation, adopt a dolphin, or just find out more about us and our important research, at www.taras.org. Keep in touch by liking our Facebook pages (Palm Beach Dolphin Project and Coastal Dolphin Conservation). You may also call me at 561-762-5770.

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