"Certainly there's evidence for courtship. It seems to certainly be a courtship display that facilitates mating interactions with females," he said.
Smith said the characteristics of the song were possibly being used by the females to assess the singing males.
"The way they structure the songs, perhaps using particular elements like higher or lower frequencies ... how well they do that could reflect attributes of that male, such as his fitness, maybe his age," he said.
He said the songs — made up of chirps, moans and barks — were repetitive but structured and could be detected as far as 20 kilometers (12 miles) away.
"The singing can last as long as 10, 15, 20 minutes to as long as 23 hours. On average, we are looking at three hours," Smith said.
Smith has worked with a team of scientists and volunteers to track whales off the eastern Australian coast for three years as the sea-dwellers migrate south from their breeding areas near the Great Barrier Reef.
"We've still got such a long way to understanding the humpback whales and the social systems involved," he said.
Name: Humpback Whale (
Megaptera novaeangliae)
Primary Classification: Mysticeti (Baleen Whales)
Location: Worldwide oceans.
Habitat: Polar to tropical oceans.
Diet: Plankton and small schooling fish.
Size: Up to 46 ft in length and 33 tons in weight.
Description: Dark blue-black above; pale or white patches below; several throat grooves or pleats; very long flippers with knobs or tubercles on leading edge; fatty pad at base of dorsal fin; slight ridge from dorsal fin to tail; very long tail flukes.
Cool Facts: Of all the baleen whales it is the most likely to accumulate parasites, such as whale lice and barnacles, because of its leisurely swimming speed. Males sing unique songs during the mating season that can last up to 20 minutes and are often repeated for several hours.
Conservation Status: Vulnerable
Major Threats: Entanglement in fishing gear, pollution and collisions with ship traffic.
What Can I Do?: Visit
The Whale and Dolphin Conservation Society,
Ocean Alliance and
The Ocean Conservancy for information on how you can help.
