Along the Georgia and South Carolina coasts, bottlenose dolphins are exhibiting a very distinct and noteworthy behavior: strand feeding.
Also known by their Latin name, Tursiops truncatus, bottlenose dolphins will work together to herd fish in a small area and create a wave that washes the fish out of the water onto the shore bank. The mammals will then strand themselves onto the shore for mealtime before wiggling their way back into the water, according to Allison Williford, a senior educator at Tybee Island Marine Science Center.
“It is not a hunting strategy they have instinctively,” Williford said. “For reasons unknown, dolphins that strand feed always lay on the right side of their bodies when on the bank. For this reason, when teeth are collected during a dolphin necropsy, scientists can determine if the dolphin used strand feeding as a foraging method because the teeth on the right side of the body would be more worn.”
A combination of muddy banks and large tidal swing make the Georgia and South Carolina coasts ideal for strand feeding. Williford describes the ritual as a cooperative and learned behavior, meaning the dolphins exhibiting the behavior had to have seen other animals exhibiting this same behavior.
Williford also works in the Marine Science Center’s animal husbandry department. The center, which is located just a few yards from the Tybee Island Pier, hosts educational walks, camps and live wildlife exhibits, among other educational ventures.
Williford’s passion for marine wildlife education traces back to her years studying marine science at Savannah State University. During her time as a student, she was an intern in the Savannah State University Dolphin Sciences lab.
“As an intern, I would help conduct dolphin surveys, which included everything from recording data to taking pictures of dolphins’ dorsal fins as they moved through the water,” Williford said. “The data and pictures collected allowed the SSUDS lab to learn more about the populations and social structures of bottlenose dolphin around Savannah, Georgia.”
Working in the SSUDS lab greatly influenced Williford’s ability to identify the difference between strand feeding and a dolphin in distress.
“If the dolphin is out of the water but has a fish in its mouth and is actively feeding, the dolphin is strand feeding,” Williford explained. “A dolphin in distress would most likely not be feeding. A stranded dolphin that is in distress may be motionless or very lethargic. Other signs may include, but are not limited to, boat scars, entanglement, rolling in the surf, and disorientation.”
Another behavior bottlenose dolphins exhibit in the Savannah area is begging, Williford said. This is when a dolphin comes within 1 meter of a boat and sticks its heads out of the water in search of a “handout.”
“This behavior most likely started when dolphins learned that shrimpers around Savannah would discard their (unwanted catch) overboard, giving the dolphins an easy meal,” Williford said. “Dolphins, however, do not just try to get free food from shrimp trawlers, but will also try to beg from recreational boaters as well.”
Though the begging behavior may be a hard for visitors to resist, Williford insists it is in the best interest of the dolphins. Dolphins can sustain injuries from boat propellers if they get too close to watercraft. Like strand feeding, begging is a learned trait, which means young dolphins may learn from their mothers to beg as opposed to foraging independently. Such practice can lead to malnutrition and eventual death if young dolphins never learn how to hunt on their own.
“If beachgoers or boaters ever come across bottlenose dolphins exhibiting either of these behaviors, it is best to watch from a distance,” Williford advised. “It is illegal to harass, feed, or even attempt to feed these wild animals. It is also illegal to come within 50 yards of any marine mammal in the wild. The goal is to keep nature natural.”
Williford advises beachgoers and boaters who think they see a dolphin in distress to contact the state Department of Natural Resources (1-800-2-SAVE-ME) or the Marine Mammal Health and Stranding Response Program of NOAA (1-877-WHALE-HELP).
https://www.youtube.com/watch?v=FE49xEU_z7g
Written by Emilie Kefalas.
