An ongoing Cedar Key dolphin project is revealing a few new discoveries and, as a result, is leading to more questions, according to Stefanie Gazda, a University of Massachusetts doctoral candidate in charge of the study.
Gazda, who has been intermittently studying the unique feeding behavior of the dolphins since 2001, gave an update on the project to about 60 audience members at the Cedar Key Public Library last week.
The dolphins’ capacity to drive fish in a sort of cooperative hunting expedition is what brought researchers to the area more than a dozen years ago. Cedar Key dolphins have a version of “driving” where a dolphin swims in a circular fashion, causing schools of fish to become airborne and, ultimately, easy pickens’ for other dolphins waiting nearby. Similar behavior has been seen in other areas, Gazda said, but Cedar Key dolphins have a unique brand of the practice.
But scientists are still working to understand the complexities involved in dolphin life in Cedar Key, she said, and the slippery mammal’s relatively long life span, estimated to be past 40 years in some animals, presents a good opportunity to do that.
One area the study is focusing on is how individual behavior affects the group dynamic, Gazda said. While the dolphins sometimes hunt fish together, they don’t necessarily forage for other food together.
“The dolphins have different levels of how they associate,” she said.
Researchers in Cedar Key want to know why. It could be because they are competitive, she said, or simply “because they can” because of a lack of area predators such as tiger sharks, which are known to attack dolphins.
Dolphins, as a group, have typical ways of going about business, she said. Male and females tend to pair or group with the same sex during much of the year, but that’s not the case with two Cedar Key dolphins known as Moon and Oval.
“They’re always together,” Gazda said. “They act like a male/male pair.” But Moon is a female and Oval is a male. “This is slightly unusual.” Oval could be Moon’s calf, but if so, Gazda referred to him as a “momma’s boy” because he has stayed with the female longer than the time most young dolphins break away from their mothers. “There seems to be a very long-term bond between the two.”
The case has led Gazda to question how the role of gender relates to social structure.
Another dolphin, a creature known as Tall Fin, is helping Gazda understand the relationship between group feeding behavior and individual performance.
Early in the study, Tall Fin, a dolphin well versed in the art of mullet driving, was always seen exhibiting the behavior with two other dolphins. Year later, it was just Tall Fin and one other dolphin, and now, as of 2010, Tall Fin drives by himself.
“There’s been a breakdown of the group from three to two to one,” Gazda said, which, again, is unique to Cedar Key. The project aims to understand how this will affect the dolphin.
For now, she said, “It looks like he’s not affected by the loss of his companions.” Did the others leave him because “he’s not very good?” she asked. “We don’t know.” Gazda said she wants to determine if the feeding behavior is instinctual or a skill that is learned.
“Tall Fins genes may help determine that,” Gazda said, referring to skin and blubber samples taken in 2010 by a number of dolphins. The data, though collected, has not been looked at, yet.
The driving behavior itself has spread out, too, she said, moving to areas beyond the two main locations –Seahorse Key and Corrigan Reef—where it was first studied.
“It’s hard to keep track,” she said, encouraging future community involvement in observation of the animals. “They are world-famous Cedar Key dolphins.”
Another question being looked at is how fish populations correlate with the use of particular habitats. Gazda said the project is in part relying of fish population data from the Florida Fish and Wildlife Conservation Commission.
“There clearly is much to do here,” she said. “Years and years of research.”
Gazda also told the audience that the project could benefit from donations, stating that there’s not a lot of money going into dolphin research.
For more information about the project, visit cedarkeydolphinproject.org or contact Gazda at email@example.com.