Air Date: Week of November 8, 2002

The Hawaiian Islands Humpback Whale National Marine Sanctuary is the only sanctuary in the United States devoted to one species. It’s also the only place where humpbacks reproduce in this country. Dr. Jim Darling goes to the sanctuary every year to study the song of the humpback whale. As Heidi Chang reports, he’s made some unusual discoveries.

Transcript

CURWOOD: Each fall, thousands of north Pacific humpback whales migrate from their summer feeding grounds off Alaska to winter near Hawaii. The Hawaiian Islands Humpback Whale National Marine Sanctuary is the only place where humpbacks reproduce in the United States. The sanctuary covers 1,400 square miles of ocean, and scientists come here to do research. One of them is Jim Darling, who studies the humpback whales’ songs. Heidi Chang has this profile.

[BOAT MOTOR IDLING]

CHANG: It's early on a sunny and warm Hawaiian morning. Zoologist Jim Darling is at the helm of his research boat as he takes off from Lahaina Harbor. He's on a personal quest.

Jim Darling in his boat “Never Satisfied” in the waters off Maui.
(Photo courtesy of Whale Trust)

DARLING: We're going to go out and find some whales. Okay? Here we go.

[BOAT MOTOR REVVING]

CHANG: As Darling heads out to sea, the historic whaling town of Lahaina, Maui fades away in the distance. The town is a magnet for tourists during the peak of the whale mating season. Since 1997, these waters have been designated as the Hawaiian Islands Humpback Whale National Marine sanctuary. It's here the whales come to breed, calve, and nurse their young.

DARLING: There is no question that this is a special place. I mean, I don't think anybody who has been here, certainly who has been out in the water, would deny that this is one of the really special places in the world regarding whales.

[WATER SPLASHING AGAINST BOAT]

CHANG: The goal of the sanctuary is to help in the recovery of humpback whales that were once nearly hunted to extinction by the early 20th century. International laws now prohibit the hunting of humpbacks, and in the 1970's, the humpback whale was listed under the Endangered Species Act. Currently, scientists estimate there are 8,000 humpbacks in the North Pacific. Nearly two-thirds of that population migrate to Hawaii. The rest breed in Japan or Mexico. Recent studies show the humpback population in Hawaii has been increasing annually by seven percent.

DARLING: Almost certainly the conditions in Hawaii, the warm waters, clear waters, shallow banks, are conditions which are beneficial to the reproductive success of these whales.

CHANG: Jim Darling has been coming here for the past five years from Vancouver, Canada. He's leading a study of humpback whale song for Whale Trust, a non-profit research and education organization he co-founded on Maui. And there's plenty of action to observe.

[BOAT MOTOR AND WATER]

CHANG: On this morning, it's not long before a huge whale breaches nearby. It's twice the size of the 20-foot long research boat. Soon, Darling spots another whale in the distance and moves in closer to it.

[HYDROPHONE SPLASHING INTO WATER]

CHANG: Darling quickly tosses a hydrophone, an underwater microphone, into the water, and begins recording the whale's haunting song.

[WHALES SINGING]

DARLING: Oh, I don't think there is any question that the most unique thing about humpback whales is their song. You know, most other whales, I would say virtually all other whales, make different types of sounds, and indeed, some of them can be classified as songs. In other words, they're a series of sounds which are repeated, but none of them come close to the kind of loud, complex song of the humpback whales.

CHANG: While some people may try to compare humpback songs with human songs, even going so far as describing them as arias, Darling says there is no equation.

DARLING: Oh, I think they sound like a barnyard in the morning. [LAUGHS] You know, it depends, really. They sound incredibly beautiful often from a distance, and often if you're in deep water where they're echoing off canyons and things like that. I mean, they're remarkably beautiful things to listen to. When you're really close like we are, in other words, when you can virtually, not virtually, when you can actually see the singer below the boat, and the hydrophone is just a few feet away from it, they're pretty loud and screechy. I mean, they're sort of hard to listen to.

[WHALES SINGING]

CHANG: These giant creatures first captivated Darling while he was growing up in Canada, and began studying them in the 70's.

DARLING: I used to, you know, run charter boats and surf a lot on the west coast of Vancouver Island, and we'd see whales all the time, and take people out to look at whales, and they'd start to ask questions. And when I went back to libraries and so on and tried to find answers just so I could sort of provide some information, I found we really knew very little about the animals.

[SOUND OF WATER]

CHANG: Jim Darling is now one of the leading experts in whale song. While other researchers may study groups of whales from different regions and compare the differences and similarities in their song, Darling's approach is unique. He studies the day in the life of individual whales to better understand their behavior patterns and the function of song.

DARLING: I think, almost undoubtedly, the prevailing hypothesis has been that males sang to attract females. There is, unfortunately, virtually no proof for that.

[SOUNDS OF WHALES]

CHANG: Darling was one of the first scientists to discover that only males sing, apparently as part of their mating strategy. And he became the first scientist to propose that the male's song attracts other males.

DARLING: I think it's quite clear now that the song it at least and perhaps primarily a signal between males, and it doesn't repel them, it in fact attracts them. You know, males sing until they interact with another male.

CHANG: Darling thinks song could serve as some form of status display, or may help determine the social order of male whales.

[RADIO STATIC]

NICKLIN (ON RADIO): Hello?

CHANG: On this journey, as Darling follows a singing whale, he's assisted by National Geographic whale photographer Flip Nicklin who's on another research boat nearby.

NICKLIN (ON RADIO): Hello?

DARLING: Yes, are you still with that singer?

[SOUND OF WATER]

NICKLIN (ON RADIO): Yeah, we're still out with him.

DARLING: Okay. Well maybe we'll just sort of slowly drift down that way and take a look at it. Thanks.

[SOUND OF BOAT MOTOR]

CHANG: The boats stay in touch by two-way radio, and keep track of what happens when a singing whale is joined by another male. Each boat is prepared to follow a different whale once the whales split apart and head in different directions.

A typical whale stays under water about 10 to 15 minutes before surfacing to breathe, and its song can last anywhere from five to 25 minutes. But this particular singing whale turns out to be unpredictable. As it begins interacting with another whale, it becomes even more challenging to follow by boat. Both males are moving fast, traveling together at about five miles an hour. As their shiny black dorsal fins roll in and out of the waves, they blow as they surface for air.

[WHALE BLOWING]

CHANG: In the end, Darling loses track of the initial singer, as both whales go their separate ways. So calling it a day, he pulls into shore before sunset. Back on land, Darling listens to the day's recordings.

[WHALES SINGING]

DARLING: So, what you're hearing here is the first theme, or often it's the first theme after the whale dives, and that "woo, woo, woo, woo" is really what we're calling the first theme. And then that shifts into the second theme, which is sort of a long, drawn-out screech.

CHANG: Scientists don't know why the composition of whale song evolves from season to season. They've found a song can change completely over four to five years.
On this journey, Darling hears, what he believes are, some new sounds.

DARLING: This is a bit of a new set here, and it may be something which is going to become more common over the next few years, but we'll just have to wait and see.

CHANG: Do you have any idea what he's trying to communicate?

DARLING: [LAUGHS] None, not at all.

CHANG: Well at least not yet. Jim Darling will spend the rest of the year analyzing his latest observations about humpback whale behavior and their haunting songs.

[WHALES SINGING]

CHANG: For Living on Earth, I'm Heidi Chang in Lahaina, Maui.

[MUSIC: Herbie Hancock “Vein Melter,” HEADHUNTER (Columbia, 1973)]

 

Links

The Hawaiian Islands Humpback Whale National Marine Sanctuary