The Associated Press reported that several sightings of humpback whales in waters within a mile New York City, which borders the Atlantic Ocean. Humpback whales are an endangered species, but since 2010 sightings of the animal have become increasingly frequent.

“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,” Howard Rosenbaum, director of the Wildlife Conservation Society’s Ocean Giants program, said, according to FOX News.

Over the past year there were 87 sightings from boats, as reported by The Washington Post. Using markings and other physical traits, naturalists determined a total of 19 different whales. ABC News stated that the International Whaling Commission has estimated a worldwide population of 150,000. The 19 who are making their appearances around New York City tend to stay away from New York Harbor, in the area beyond where Rockaway Peninsula in New York and Sandy Hook in New Jersey meet.

“It was pretty slim pickings at first, actually,” Paul Sieswerda, founder of Gotham Whale, said about documenting the then purported sightings. “We went on many cruises and had three sightings totaling five whales in 2011.”

The Associated Press reported that the spike in sightings is most likely due to a change in their habits rather than an increase in numbers. Another possibility is that a greater amount of menhaden, a favorite food of humpback whales, is available closer to the city. This would mean that the water is cleaner, including the Hudson River, and making a safer environment for the whales to inhabit.

“One would like to think that some of this has been triggered by an improved environmental ethic,” Rosenbaum said. “We have the clean air and clean water acts, the Marine Mammal Protection Act and associated state laws. It’s hard to make the link for sure but there’s certainly been a behavioral change toward the natural environment.”