Great white sharks, also known as white sharks, are typically solitary and fierce predators at the top of the ocean’s food chain, said Robert Hueter, the chief scientist at OCEARCH, a Utah nonprofit that studies marine life. But Hueter, who has studied sharks since the 1970s, said he had never seen white sharks travel similar routes at the same time for months.

The male sharks near Canada, whom scientists named Jekyll and Simon, swam about 4,000 miles and were last tracked together in July off Quebec’s eastern coast.

Hueter, 71, doesn’t know why the sharks are traveling together, but he said he’s awaiting blood sample results to determine if Jekyll and Simon are related.

White sharks “were already more complex than we used to think they were,” Hueter told The Washington Post. “Now this adds a whole new element of sort of a familial and social component to migration.”

OCEARCH, based in Park City, Utah, began tracking sharks in the Atlantic Ocean in 2012. Scientists catch white sharks and collect their blood, mucus, feces and urine samples. They measure their bodies and eyes and give ultrasound exams to female adults. Then they place three tracking devices on the sharks: in their abdomen and on their skin and dorsal fin. Within 20 minutes, scientists are able to release the sharks back into the ocean.

By monitoring white sharks, the scientists hope to learn where they live, breed, eat and migrate to identify areas where the vulnerable species needs protection.

To date, OCEARCH has tracked 92 white sharks, including Simon and Jekyll. Simon, who’s 9½ feet long and 434 pounds, was caught near St. Simons Island, Ga., on Dec. 4. Jekyll was caught five days later near Jekyll Island, Ga., and was measured to be 8-foot-8 and 395 pounds. Hueter said the two sharks are between 10 and 15 years old.

In April, Jekyll and Simon began swimming up the Atlantic Coast, passing Ocracoke, N.C., Virginia Beach and Atlantic City at similar times. While none of the other tracked white sharks have moved in pairs, Hueter said Jekyll and Simon have stayed between 10 and 100 miles of each other.

Sharks sometimes spend time in the same areas to mate and eat, Hueter said, but they typically migrate alone — to the north in the summer and to the south in the winter. Other animals, including birds, salmon and caribou, migrate in groups.

“Social behavior in sharks is something that’s not particularly well-known,” Hueter said. “And it’s not thought to be something that they have much of, except in maybe isolated cases of certain species.”

On July 4, Hueter raised new questions about sharks’ migration patterns when he saw Jekyll and Simon arrive near Nova Scotia’s southern coast. He wondered whether their shared sex or their similar physical dimensions drove them to travel similar paths. He’s also curious if they’re siblings. If Jekyll and Simon are related, that might show that sharks are closer to their families than previously thought, Hueter said.

Both sharks have since swam past Halifax — Nova Scotia’s capital — and around the Gulf of Saint Lawrence. Jekyll’s tracking device last reported him on Quebec’s eastern coast — near Chandler — on July 18. Simon was in that area on the same date.

Simon’s sensor last pinged on Aug. 11 on the northeastern coast of the New Brunswick province. When Jekyll’s tracking device pings again, Hueter looks forward to seeing if he joined Simon there.