Maybe they want to sing on Broadway.
Humpback whales, the gigantic, endangered mammals known for their haunting underwater songs, have been approaching New York City in greater numbers.
Naturalists aboard whale-watching boats have seen humpbacks in the Atlantic Ocean within a mile of the Rockaway peninsula. That is part of New York's borough of Queens, within sight of Manhattan's skyscrapers.
"It is truly remarkable, within miles of the Empire State Building, to have one of the largest and most charismatic species ever to be on this planet," said Howard Rosenbaum. He is director of the Ocean Giants program at the Wildlife Conservation Society.
Humpbacks were spotted 87 times from the boats this year. By cataloging the whales' markings, at least 19 different humpbacks have been identified in the waters off the city.
Paul Sieswerda is founder of Gotham Whale. The organization documents the marine mammal population around New York. It said reports of humpbacks in the New York Bight, where the city's harbor meets the Atlantic, began to pick up around 2010 from surprised fishermen and other veterans on the water. Gotham Whale then partnered with the American Princess whale-watching boat, providing naturalists who could document the sightings.
The naturalists also do an educational presentation on the boat and answer customers' questions, said Tom Paladino, the boat's captain.
"It was pretty slim pickings at first, actually," Sieswerda said. "We went on many cruises and had three sightings totaling five whales in 2011."
But in 2012, there were 15 sightings. In 2013, there were 33. This year there were 87 sightings totaling 106 humpbacks.
Many whales were sighted more than once. By comparing flukes the distinctive shapes and markings of their tails 19 different humpbacks have been documented near the city so far. Customers on the whale-watching tours are asked to share any photos they get of such markings for the "New York City Humpback Whale Catalog."
"This is the way they've been doing it in Maine and Massachusetts, the recognized way to keep track of these whales, study their behavior," Sieswerda said.
It's not clear why humpbacks, which can be 50 feet long and weigh 40 tons, are returning to New York's shores. They were abundant before they and other whale species were nearly destroyed by whaling.
Rosenbaum said the humpbacks' reappearance could be simply a shift in their habits. A greater abundance of menhaden, one of the humpbacks' favorite foods, could have attracted them from farther out in the ocean.
That might be because the water is cleaner.
Sieswerda agreed that various factors are in play but said, "I think it all begins with cleaner water," including the improved Hudson River.
Whatever the cause, humpback populations worldwide are increasing. Counting whales is difficult. But the International Whaling Commission says its latest estimates put the worldwide population at about 150,000. About 11,600 of those are in the Western North Atlantic. The area includes the New York Bight off New York City. There might have been just hundreds before whale protection laws were passed.
New Yorkers shouldn't expect to see humpbacks frolicking around the Statue of Liberty. Except for the occasional disoriented calf, the whales generally stay well outside the harbor.
Critical thinking challenge: Why doesn't the International Whaling Commission know precisely how many whales there are worldwide?