Humpback Whales often "sing," vocalizing a long series of repeated phrases; the vocal patterns are apparently specific to separate populations of whales but may vary from year to year. It is possible that individual animals can be recognized by some of their sounds. Songs can last up to 10 to 12 minutes and can be repeated continuously for hours. Scientists believe that only male humpbacks sing, but they aren't sure of the purpose. The whales appear only to sing in their reproductive habitat, so the songs may play a role in reproduction. The songs may serve to attract females or to maintain distance between males. Preliminary data show that the songs are louder at night, which may indicate that there is more reproductive activity at this time. Other humpback vocalizations consist mostly of groans and grunts, and scientists haven't determined meanings for most of these sounds. Since humpback whales do so much audio communication, noise pollution in the ocean can really affect them. Observers have seen humpbacks move away from bothersome sounds, change their breathing and diving patterns and display seemingly aggressive behavior in response to these noises.
Humpbacks sometimes leap clear of the water and may be seen slapping their flukes or a flipper on the surface. They are the only large whale that regularly breaches, rolls, then comes crashing down.
Mother whales are pregnant for one year. They give birth to one baby, and that baby can be 16 feet long at birth. The babies are born in the tropics, but they must migrate north with their mother. They stay with their mothers for one year. In four to six years, they are sexually mature. Humpback whales can produce a baby once every two to three years.
Males appear to compete for females. They hit each other with body parts, hit each other with their heads ("head slaps") and slap their tails against the water. In some cases, they fill their mouths with water — possibly to make their heads heavier — and then head slap each other. Sometimes a male blows bubbles to create an underwater screen. As the female swims through the wall of bubbles, she briefly disappears from view. The male uses this moment to divert her direction and shake his competitors from her path.
Mothers teach calves about whale communication. For example, a mother humpback do a big breach and then watch her calf follow with a sloppy little breach. The calf will breach again and again, as if it is practicing the behavior.
Every year, they migrate from cold, polar feeding areas to warm breeding, calving, and resting areas. Humpbacks don't feed when they are in warmer regions, which are nutrient poor compared to northern regions.
Scientists believe that whales sleep half a brain at a time. Whales are "voluntary breathers," which means they need to tell themselves to take each breath of air. If they were totally unconscious, they wouldn't be able to think about coming to the surface and breathing.
The average dive is 5-15 minutes, but only three to five minutes
for calves. Humpbacks can hold their breath for 45 minutes, but long dives
are unusual. Whales have very efficient lungs. Humans exchange only 15-20
percent of the air within our lungs with each breath. Whales exchange more
than 90 percent. A humpback's lungs are the size of a compact car!