by Johanna Kent

Created on: January 06, 2009

Traveling back and forth from the polar regions of the world, where big weather and food abounds, to tropical climates with gentle breezes and calm waters, humpback whales lead a nomadic lifestyle that many humans would envy.

However far their travels seem to take the whales, these impressive creatures live a very regular and cyclic life. How the cycle continues is due to motivations that prompt the whales to travel huge distances every year. Humpbacks manage to navigate thousands of miles between destinations, and their behaviors observed at each location indicate an animal completely adapted to life in the ocean.

At the end of the summer months, humpback whales begin their journey towards the equator. The algae bloom in the nutrient-rich waters of the polar regions that sparked an incredible growth in plankton is over, unraveling the base of the food chain, and ending the abundance of food for the whales.

Harsh weather will begin soon. While adult humpbacks would not be overly troubled by monster storms and washing-machine-waves, a newborn calf with weak muscles would struggle to remain with its mother, trying to time its breathing precisely between waves.

A percentage of the females heading back to the tropics are pregnant and due within a few months, and many of the other females will be ready to mate soon. Like many mammals, mating requires a significant amount of interaction between adult humpbacks. These interactions would be largely impossible in high sea conditions and at the very least, not very romantic.

Perhaps most important, the whales are heading to locations that have far less predators in waters that are considerably less deep. To a mother and her newborn calf, the safety of shallow, crystal-clear water from predators that may rise from the deep (specifically orcas or "killer whales") are a top priority, and sightings of orcas in tropical waters are rare.

The migration to warmer waters takes about six-eight weeks. Humpbacks tend to be solitary travelers, sometimes seen in pairs, but not usually for long. The only exception to this are mother and calf, and then only as they return from the tropical birth place. A yearling is almost never seen in the company of its mother.

Biologists aren't sure how the whales navigate such a long journey. No one underestimates the possibility of long memories in these whales, so one common theory is recognition of key coastal landmarks on the ocean floor. Other theories relate to the supreme eyesight of whales, both

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