Look around yourself. What do you notice? Without always realizing it, every piece of your life is deeply defined by culture. Our languages, music, relationships, and even how we share information are all rooted in culture. But culture is not just for us humans. Throughout the animal kingdom, different cultures are celebrated and even used as a tool for survival.
Feeding culture of whales and dolphins
Whales and dolphins are famous for their unique cultures. How they use their big brains to flourish continues to astound researchers. One of the best-known examples of these variations in cultures is the feeding patterns of bottlenose dolphins. They have seemingly mastered the art of teamwork and trickery to feed themselves in uncanny ways. From surrounding prey with a ring of mud to using sponges as tools to protect their noses, this species has cleverly innovated their hunting strategies.
And we’re willing to bet that you wouldn’t guess this sometimes involves dolphins swimming onto land for a bite. As impossible as this might sound, strand feeding is a documented fishing method in multiple species of dolphins, including even massive orcas. These variations in feeding tactics beautifully portray the extraordinary social structures, communication skills, and complexities of dolphin cultural variations.
What is strand feeding
Strand feeding is no simple feat. This sophisticated fishing style takes expert timing and often involves teamwork and communication. Under the surface, dolphins will usually work in small groups to herd fish tightly together. Then once they’ve corralled their prey, the dolphins form a line and accelerate to create a tidal wave that spooks their prey onto shore as they follow close behind and surge out of the water in unison. This is the exact reason why this tactic is called strand feeding, because the fish and dolphins are stranded on land together.
If successful, this creates an explosion of fish flopping in every direction on the beach. After the dolphins catch their fish in midair, they quickly proceed to thrash their bodies back into the safety of the surf. This is quite the orchestrated event, but in a splash, the whole frenzy is over in a matter of seconds.
Strand feeding in bottlenose dolphins is thought to have developed from hunting schools of fish in shallow waters against sandy banks. For decades scientists have studied the resident dolphins along the salty marshes and inlets off the coasts of Georgia and South Carolina. The most closely observed population of strand feeding dolphins resides in the waterways near Kiawah and Seabrook Island in South Carolina.
“Bottlenose dolphins are one of the most abundant marine mammals around the globe, yet a small, possibly only around 100 individuals in South Carolina, participate in this risky behavior,” says Lauren Rust, executive director of Lowcountry Marine Mammal Network, a nonprofit based in Charleston, South Carolina. “There are thousands of bottlenose dolphins along the Atlantic coast, but it takes a unique habitat and adaptation to support this special feeding.”
Dolphin mothers knows best
These traits grow from deep relationships between individuals. And complex cultural practices run throughout generations of bottlenose dolphins, some of which have been studied for nearly 40 years.
“These resident dolphins are some of the few in the world that strand feed, and will only do so if their mothers did, making it even rarer,” says Rust. “They spend years mastering this behavior with a small cohort of dolphins. For example, they are likely to strand feed with the same individuals they grew up learning alongside.”
Dolphins celebrate their unique cultures through a range of behaviors from communication to feeding techniques. But one of the most mesmerizing is their ability to transcend the surf onto shore for a momentary bite to eat.
Prime time and place to strand feed
Marine mammals are built for the surf, not the turf. While strand feeding might be effective, it’s a pretty dangerous game for the dolphins. Surging too far onto the sand means risking getting stuck. Just leaving the water makes them more vulnerable to injuries, even getting sunburnt. These risks mean finding the perfect time and place are vital for safe strand feeding.
By using the changing tide and the slope of the shoreline these resident dolphins have crafted the ideal window for strand feeding. Of course, they adjust their strategy as needed since this is just one of their many foraging techniques.
“These dolphins have adapted to living in a shallow water environment, which provides the best setting to strand feed,” says Rust.
Less water means less work in corralling schools of fish. To enhance their chances for success these dolphins typically strand feed during low tide, day or night. Primetime is during the two hours before the lowest tide and the two hours afterward. Given the constantly changing tidal patterns, this window shifts daily.
The dolphins are rightfully picky when it comes to where they’ll haul out. They are keen to avoid sharp oyster beds and even areas that are too flat and risky for getting stuck. This ‘Goldilocks mantra’ means feeding conditions need to be just right for strand feeding success. Cue Captain Sam’s Inlet – prime feeding grounds for these resident dolphins.
Captain Sam’s feeding grounds
This inlet is fed by the Kiawah River and separates the islands of Kiawah and Seabrook. The deep channel that leads to the Atlantic Ocean offers soft sloping banks with abundant schools of mullet each summer for the dolphins to eat. For the resident dolphins of this region, Captain Sam’s Inlet is a vital habitat for their unique culture of strand feeding.
“Risks at Captain Sam’s Inlet are on the rise,” says Rust. “I have spent the last five years observing the dolphins there. The small group of dolphins that spend a significant amount of time there is a hyper-local group that moves up and down the Kiawah River and comes to feed in the inlet several times a day or, sometimes, all day. Unfortunately, there’s little protection for the area.”
This increase in threats to Captain Sam’s Inlet was Rust’s motivation in creating the Lowcountry Marine Mammal Network back in 2017. Before her efforts, there was little signage or awareness of how to respect the local dolphins. Part of the mission of Lowcountry Marine Mammal Network is to educate beachgoers with these unique dolphins and encourage ethical viewing practices. That includes giving the dolphins space to strand feed, allowing 45 feet (15 yards) between yourself and the shores of the inlet.
If you arrive at the right time and remain patient, you might just be lucky and witness this incredible behavior yourself. One of the best examples of dolphin cunning cultural traits, stranding to survive.
