Humpback whales undertake a great journey, about 3500 miles one way. The waters around Hawaii are relatively warm and thus offer ideal conditions to the whales in order to reproduce. Although scientists disagree humpback calves would not survive in colder waters since they are born without a blubber layer, others argue that seals, porpoise and other mammals' young do survive. One argument that does hold merit is the fact that the orca, a strong presence in the colder waters and the one main predator to whales, does not exist in large numbers in the breeding grounds. Warm waters, however, have the disadvantage that there is hardly enough food for the whales there so they must head back to Alaska, since the cooler waters offer a "richly covered table" for the humpback whales there. During the time between the end of October and the beginning of May, the whales are on a "diet" and it is said that a full-grown humpback whale loses several tons of weight during the time it spends around Hawaii. A nursing mother may even lose a third of her weight! Researchers are also aware that not all humpbacks migrate. Humpback whales are seen off Alaska and Canada all year around. Several years ago a new baby was spotted off Prince Rupert with its mother!

We don't know for sure! Some scientists believe that at the beginning of the 19th century the humpback whales wasn't known in Hawaiian waters. However some Hawaiian chants of ancient origin refer to the "kohola lele" (the jumping humpback whale) in Hawaiian waters. It would be the only known case where whales changed their migration routes. Today, about 9000 humpbacks per year can be found in the waters around Hawaii. That is about 60% of the whole humpback population of the North Pacific. The largest concentration is found in Maui County. Here, the water is fairly shallow (less than 1.000 feet) making humpback communication more easily heard.

With the help of transmitters and satellite monitoring systems, scientists have already been able to determine the duration of their migration. Through observations of individual humpback whales, scientists estimate that they travel a distance of approximately 3500 miles between their breeding and feeding grounds in 30 to 39 days. The National Marine Sanctuary identified an individual humpback via photo-ID in Alaska and in Maui only 28 days later, which means that this particular whale traveled 3500 miles in less than a month! Humpbacks travel at an average speed of approximately 3 to 6 miles per hour, but are able to reach up to 20 mph for a short time.

Humpbacks usually aren't gregarious animals – they rarely appear in groups or so-called pods. The humpbacks do not all migrate at one time, and not all migrate. Most of the humpbacks head to Hawaii alone or a small collection, and they probably meet with other whales on the way. Scientists tell us that a collection of humpbacks is called a group. They have decided that the word ‘pod' is to be used for structured groupings, such as the families of dolphins, orca, sperm whales, and others.

There are different opinions. Dr. Jim Darling suggests an average stay of just two weeks in Hawaii waters before heading back to Alaska, others think it could be longer, but they all agree that the duration of their stay depends on different circumstances: a recently impregnated female will head back right away (a female had been identified via photo-ID on the way back after just 21 days in Hawaiian waters); a mother who has given birth will stay longer until the calf is strong enough to make the long, dangerous journey. According to Dr. Darling, the longest stay researchers are aware of is 2 months with a mother/calf pair.