The other two whales were thought to have left the area — but one whale appeared to have gotten stuck in the river, home to a large number of saltwater crocodiles.
“The whale made its way out on the high tides of this weekend and we’re pleased it appeared to be in good condition and not suffering any ill effects,” Moyle added, thanking authorities on state, local and indigenous levels for collaborating on “this very unusual situation.”
Dr. Carol Palmer, a senior scientist for the state government, called the whale’s escape “great news.”
“It’s been fantastic working with staff at Kakadu as well as expert scientists to identify ways to assist the whale, but I’m very happy it has found its own way,” Palmer said in the park’s statement. “This is the very best outcome we could have hoped for.”
The whale had apparently gotten stranded after becoming confused during migration, said the national park. “As far as we’re aware, this is the first time this has happened,” it said in a statement last week.
The park said it had been concerned about a number of dangers — apart from the crocodiles, there was also the possibility of a boat colliding with the whale or inadvertently pushing it further up the river.
Saltwater crocodiles are ambush predators that have been known to attack and kill humans. Despite their name, they can also be found more than 100 miles (161 kilometers) up river from the coast in freshwater habitats.
According to the park’s guidelines to visitors, the crocodiles can stay hidden under water for long periods and can move with great stealth and camouflage. They are quick-acting and have been known to move at speeds of up to 40 feet (12.1 meters) per second when capturing prey over short distances.
CNN’s Lianne Kolirin contributed to this report.