At 7:30 one late March morning, the sun glinted off the ocean like a field of diamonds. Three minutes outside the Lahaina Harbor off Maui, Captain Karl of Maui Adventure Cruises nosed the boat northwest. He had already spotted our first humpback whales of the morning. Thar she blows.
From a couple miles away, we could see the action. A competitive group of male whales vied for one female’s attention. The guys tail slapped. They pec slapped. And they threw their peduncles* every which way. This was serious business.
Another captain with us, Gary, said that scientists feel these explosive behaviors—some ending in bloody wounds—represent a form of communication. Like these 45-foot, 45-ton behemoths are saying, “Don’t cut in on me, buster, I was here first.” Or, “She’s mine, matie.” And, “Back off, dude, I am bigger than you are.”
Male Humpback Whales Migrate to Hawaii to Breed
When humpback whales migrate 3,500 miles from their feeding grounds of Alaska to Hawaii each year, the males do so to mate. The need to breed is so strong, they face up to four months without food to do so. As the season winds down, Captain Gary quipped, “It’s like the big stomach says, ‘I am hungry,’ and the Little Man says, ‘But I have need to breed.’” Eventually, one of two things happens: Hunger wins out, or all the females leave. Either way, the males turn north.
In February, according to Gary, in order for Maui Adventure Cruises to traverse across the Au’au Channel to Lana’i for their dolphin snorkel cruises, they have to dodge groups of whales to get there. That’s the reason I hesitated before signing up for a whalewatching tour. A month-and-a-half earlier, I participated in the necropsy of a humpback whale calf. A mere four weeks old, this 17-foot calf washed ashore on a west side Kaua’i beach. We performed the necropsy carefully, as there had been reports of a whale and boat collision a few days before.
This time of year, though, the number of whales in Hawaii decreases by about one-third, per Gary, and that eased my fears of harming one of these endangered cetaceans. Since there are fewer females, though, the fighting for who earns the rights to continue their gene pool gets ferocious. “Much more goes on below water than above,” said Karl, who volunteers his captain’s duties to a research boat one day a week. Like one whale t-boning another in the genital regions.
Humpback Females Calve in Hawaiian Waters
Silly me. I knew very little about the mating behavior—and violence—practiced by whales in Hawaii. My thoughts veered more toward the birthing rather than the breeding. I found facts like these fascinating: 1) the humpback whale calf measure 15 feet in length when it is born, and during a few short months, it grows to 30 feet by the time it departs for Alaska; 2) the calf consumes on average 100 gallons of milk per day and gains on average 100 pounds of weight per day; and 3) mom loses one-third her body weight between the time she leaves her feeding grounds in Alaska and when she returns some five months later. But my focus on the mom and calf might be easily explained. I am female.
Humpback whales are not sexually active until they are 12 or 13. That doesn’t mean they’re not interested, though. Males start fighting with other males when they are half that age. Until then, “It’s like a sex education class,” said Gary. And teen dating.
Captain Karl turned out boat around when three other whalewatching vessels approached, and we started jockeying for position. If we weren’t careful, we’d be head butting and tail slapping each other for a view of the action. Plus, we’d found ourselves sideways to the waves jumbled up by the tradewinds whipping around the island. The boat rocked. “Let’s find some whales in calm water,” said Karl.
Male Humpback Whale Competition Continues Under Water
And we did. We spent most of the next—and last—hour of our whalewatching tour observing five adult whales—we never did spot a calf in this group. They behaved much more civil. Maybe they were older. Maybe all the action was going on underwater. At times, we spotted “footprints” on the water—calm areas created by tail flicks, pec slaps and other movement just below the water. One male kept lunging above with his head above water and taking big gulps of water. Karl said the water would inflate his pleats and make him look bigger to the other males.
We also followed the direction of the whales below the surface of the water by scanning the horizon for moving blocks of turquoise color. Once, deep below us, a whale swam under our boat. All I could make of it, though, was the discoloration of the water column.
A depth gauge revealed the water inside the triangle of Maui, Lana’i and Molokini is shallower on average than anywhere else around the Hawaiian Islands. I could see clear to the bottom, some 120 feet down. The water shimmered an inviting cobalt blue. No microorganisms floated in the water giving it such excellent visibility. It looked pretty to me, but it also explains why humpback whales only migrate to Hawaii, rather than move permanently.
The mid-Pacific Ocean is nutrient poor. Its warm waters do not produce the zooplankton that whales like to eat. While humpbacks—with scientific names of Megaptera novaeangliae, which means "Big wings of New England”—lose weight because they do not eat while they are here, they also drop about 2,000 pounds of barnacles. Barnacles, like zooplankton, cannot survive in the mid-Pacific waters. That means a visit to Hawaii is like going to the spa for a micro-derm abrasion treatment.
Humpback Whale Song: Woos or Warnings?
Gary and Karl dropped a hydrophone in the water, hoping to hear some singing. In the breeding grounds of Hawaii, male whales tilt their heads down in the water, spread their long pectoral fins and emit a sequence of groans, snores, sighs and chirps over and over. Throughout the season, the song grows and evolves and can be heard as far away as 100 miles. Next season, the males create a new song. Scientists don’t really know why the big guys sing, but because the songs are belted out exclusively in the mating grounds by only the males, scientists expect the obvious: Singing and mating go together. But whether the whales are wooing their lovers like Frank Sinatra or are beating their chests to claim king of the jungle status, we don’t know.
We listened as the hydrophone picked up some faint strains of song. Someone was floating in an inverted cross position somewhere, but it wasn’t the whales 100 yards away. They may have been lunging and head-butting, but they weren’t singing. At least, then.
I arrived on Maui wondering whether I could enjoy the amazing wonder of whales without having to step foot on a boat—without having to disturb their world, without risking injury to them by a boat strike. I departed Maui feeling two things: 1) No land-based whalewatching I have ever experienced compares to that from a boat; and 2) Maui truly is no ka oi when it comes to whales. Still, I wonder whether there shouldn’t be some limitation on how many boats can ply the whale’s world during peak season and in population-dense areas.
*According to Captain Karl, the caudal peduncle—the area behind the whale’s dorsal fin—is the strongest muscle in the animal kingdom.