It’s again that time of year when people living on the mainland brace for frigid temperatures and snow days. But in Hawai’i, it’s the season where residents give their warmest welcome to their favorite visitors: humpback whales. 

Each year, an estimated 11,000 humpback whales migrate to Hawai’i from colder waters in the northern part of the Pacific Ocean to mate, give birth and nurse their young. This year, the first official sighting on Maui happened on Oct. 9 in the ʻAuʻau Channel between Maui and Lānaʻi, according to the Pacific Whale Foundation. It came just a few days after a tour boat in Kaua’i reported the first sighting in Hawaiian waters. 

About 60 percent of all North Pacific humpbacks make the nearly 6,000-mile round trip to the islands, where about 80 percent will choose the waters of the Au’Au Channel, between Maui and Lanai, as their wintertime home, according to the Keiki Kohola Project, a nonprofit that works to protect humpback whales in the islands. The whales usually start the journey in late fall to early winter, then return to the chillier North Pacific waters in the spring. Then, they make their way to Alaska for the summer to feed.

After more than 45 years of being classified as an endangered species in the U.S., the federal government in 2016 removed most humpback whales from the list, saying their populations had recovered. However, they’re still protected by other federal and state rules, which limit ships and other watercraft from approaching humpback whales within 100 yards.

But just because most humpbacks have been taken off the endangered species list doesn’t mean they aren’t still in need of conservation. Last year, researchers met to discuss a significant drop in the number of humpback sightings in Aloha State, the Associated Press reported. Their fear: The disappearance could be linked to climate change and warmer ocean temperatures — and their effect of the whale’s food supply. The news outlet reported the decrease over the last four years is estimated between 50 and 80 percent.

Want to learn more about Hawai’i’s humpback whales, including ways to help them? Visit the Keiki Kohola Project’s website by visiting CaringForCalves.org.