The Humpback FAQ |
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Family stories Why is the humpback whale called a humpback whale? What special characteristics do humpback whales have? How long do humpback whales live? How large do humpback whales become? How many humpback whales exist? What threats are endangering the humpback whale? Can we find humpback whales in all seas? Why do the humpback whales migrate? Do humpback whales always return to Hawaii? How long are the humpback whales on their journey? Do humpback whales migrate alone or in pods? What kind of social bonds do humpback whales exhibit? What is the difference between the populations of North and South Pacific? Are the populations of North and South Pacific mixing together? How long do the humpback whales stay in Hawaii waters? How can one identify an individual humpback whale? How do humpback whales reproduce? How do humpback whales sing? What is known about their singing? Why do humpback whales sing? What can we learn or use from their singing? How long does a whale's song last? Do humpback whales sing the same song everywhere? How far do the songs travel under water? Why do humpback whales breach? How good can humpback whales see? Can humpback whales see in color? How long can humpback whales dive? What is a spout? Do humpback whales sleep? What do humpback whales feed on? Do humpback whales eat the oceans empty? How do humpback whales hunt it's prey? What are baleen plates? The order of cetaceans is distinguished between two suborders: toothed whales (orcas, sperm whales) and baleen whales, the group to which the humpback whale belongs. In this family of whales, the humpback whale has five siblings: the Blue -, Fin -, Sei -, Bryde's and Minke whales. Altogether there are approximately 80 kinds of whales, and the baleen group contains both the largest (Blue whale) and the smallest (Minke whale). The Blue whale is the largest animal that ever lived on our planet: it can grow more than 90 feet long and weigh up to 180 tons. Its heart is as large as a small car! The Minke whale grows “only” to about 27 feet long... At Whalesong, we concentrate on the largest and most famous cetacean to the waters around Hawaii, the humpback whale: Class: Mammals (Mammalia) Order: Sea mammals (Cetacea)Subordination: Baleen whales (Mysticeti) Family: Rorquals (Balaenopteridae)Kind: Humpback whales (Megaptera novaeangliae) Why is the humpback whale called a humpback whale? The humpback whale probably got its name from early whalers that designated the whales based on their observations. When diving into the deep, the whales make what appears like a “hump” coming out of the water, a characteristic which differentiates them from other whales. There were also theories which attributed the name to dents at their pectoral fins and at the head. These dents contain hair bellows, or pores from which hair grows. What special characteristics do humpback whales have? Although humpback whales differ from their other family members in many ways, one characteristic that is the same with all six family members is the way the throat grooves, or ventral pleats, are situated. All of the baleen whales have 14 to 35 throat grooves which run from the chin to the navel. The main difference between the humpback and the other whales is that their flippers are unusually long - up to approximately 15 feet, which is up to a third of their whole body length. Therefore, they also have the scientific name Megaptera novaeangliae, which means "Great Wing of New England." The reason the flipper is so long is still a mystery, as well as the fact that sometimes the whales lie on their side and lift one flipper into the air for hours, as if they were waving to someone. This behavior can mainly be observed in the breeding areas. How long do humpback whales live? Scientists estimate a life expectancy of up to 50 years, maybe even longer. The age of a humpback can be estimated by analyzing its waxy ear plug, which prevents water from pouring in. This ear plug consists of different layers, similar to the yearly rings of trees. The different layers come from their stays in Hawaii and Alaska. The ear wax they build up in Alaska is usually darker than the build-up from their time in Hawaii. The number of layers gives information regarding the age of a whale, although it is not 100% accurate because the whales are not traveling every year. For example, a female trying to avoid getting pregnant again will just stay in Alaska, and therefore not build up another layer of wax. How large do humpback whales become? Humpback whales are already up to 15 feet long and weigh about 1 ton at birth. A full grown humpback whale (at the age of 12) could grow up to 45 feet long and weigh up to 40 tons, with the females usually being longer and heavier than the males. Their fluke grows to be nearly 15 feet wide - as long as their pectoral fins are. 40% of their weight are muscles! How many humpback whales exist? The estimations of the current population vary widely: some speak of 5,000-7,000 animals, and others of 12,000-14,000 animals. Even if there were 14,000 animals, that would only be a fraction of the originally estimated population of approximately 115,000 animals. The humpback whale's existence is, therefore, considered extremely endangered. They received full protection by the International Whaling Commission (IWC) in 1963. What threats are endangering the humpback whale? The humpback has two natural threats: the killer whale and the shark. But the most dangerous threat for these creatures is human beings: Commercial whaling: Although there are international restrictions, Norway and (mainly) Japan are killing whales for so-called scientific reasons. But the meat is often found in restaurants or, as a recent plan of the Japanese government suggests, in school cafeterias. The question that one must ask is how all this is related to research. Ocean pollution: Analysis of blubber has shown traces of POP's (Persistent Organic Pollutants). A stranded sperm whale at the German coast of the North Sea had to be treated as dangerous waste because the body had been so polluted. These POP's also affect the reproduction of the whales. Noise pollution: Increasing noise pollution, in the form of underwater explorations for oil or gas, ships, air guns or newly developed underwater sonar systems, is affecting the navigational abilities of the whales. The “LFAS” (low frequency active sonar) is able to detect quiet vessels and therefore it produces extremely loud sound waves (up to 180 db!). All this could be linked to the increasing number of marine mammal strandings. Marine debris: Lost or dumped equipment from the fishing industry is an increasing danger to the whales. They are not able to see these nylon nets and if they become entangled, they will drown. More and more whales, dolphins, porpoises, sharks and other marine mammals suffocate painful deaths from entanglement. Global warming: Global warming has an influence on the whale's food chain. There will be less krill if the ice crust of Antarctica is melting, which means Blue whales would have to cover a much greater area to find enough food, leaving less food for the humpbacks. Over-fishing Several commercially used fish species are vastly over-fished, which means their population is endangered because they don't have enough time to reproduce. It's a disruption to the whale's food supply and, unfortunately, the steps to a sustainable fishing industry (with a fixed catch quota, for example) are taken very hesitantly. Can we find humpback whales in all seas? Humpback whales exist worldwide - the National Marine Sanctuary has identified 6 different populations. Whalesong concentrates on the population of the North Pacific. The majority of the population (approx. 60%) migrates into the warmer waters around Hawaii during winter time. Approximately 30% migrate to the coast of Mexico or Baja California, or to the southern islands of Japan, and the remaining 10% stay up in Alaska. They are found frequently in proximity to the coast in relatively shallow water. That gives us the possibility of being able to observe the whales well - in Hawaii you can often see the whales from the beach! They are, however, not around Hawaii throughout the entire year. The first whales come to their breeding ground in the warmer waters at the end of October, at which time they give birth to the new generation. At the beginning of May, they make their way back again to their feeding grounds around Alaska, together with the newborn generation. Why do the humpback whales migrate? Humpback whales undertake the vastest migration of all the whales. The waters around Hawaii are relatively warm and thus offer ideal conditions to the whales in order to reproduce. The newborn humpbacks would probably have no chance of survival in the cold waters around Alaska. 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 "rich 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 its weight! Do humpback whales always return to Hawaii? 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 3500 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 majority are found close to the southern and western coasts of Maui. Here, the water is shallow and the nearby islands of Lanai, Molokai and Kaho'olawe offer additional protection against heavy winds. How long are the humpback whales on their journey? 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 m/h for a short time. Do humpback whales migrate alone or in pods? Humpbacks usually aren't gregarious animals – they rarely appear in groups or so called pods. The humpbacks do not all migrate at one time. Most of the humpbacks head to Hawaii alone, although they probably meet with other whales on the way. What kind of social bonds do humpback whales exhibit? Our knowledge about the social bonds of the humpbacks is not yet distinctive. We assume that most of the bonds are only short term – the longest and most intense bond being between mother and calf, since they are inseparable for at least a year. There are assumptions of a deeper complexity which deserve study. Males could cooperate, as well as compete, with each other. For example, in their breeding grounds they compete for the best place next to a receptive female. Most of the humpbacks are hunting and feeding on their own, but about 25% get together in pods and cooperate in the foraging, though they may travel alone the rest of the year. What is the difference between the populations of North and South Pacific? The humpbacks of the North Pacific (Alaska, Hawaii, Japan, Mexico) are usually a little darker on the underside of their fluke, their pectoral fins and their throat grooves compared to the population of the South Pacific (Antarctica, Australia, South Pacific Islands). While the humpbacks sing head down in Hawaii, it's the opposite in the South Pacific. Are the populations of North and South Pacific mixing together? Usually the two populations do not mix together. Since the seasons of the year are opposite in each hemisphere, the humpbacks of the North Pacific are migrating towards Alaska in May at the same time the humpbacks of the South Pacific are migrating from Antarctica to Australia and the South Pacific Islands. In October, it just goes the other way round. But there is an exception to every rule: One season, researchers in the northern hemisphere noticed a whale with a fluke that was plain white on the underside. They couldn't find the whale in their photo-ID database and sent the photo to researchers in the southern hemisphere. Australia called right away, "Hey, this is our whale!" How long do the humpback whales stay in Hawaii waters? There are different opinions. Dr. Jim Darling suggests an average stay of just two weeks in Hawaii waters before heading back to Alaska, but the Pacific Whale Foundation believes it is more like four weeks. 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 Hawaiia waters); a mother who has given birth will stay longer until the calf is strong enough to cope with the long journey; a female which guides the yearling to Hawaii the next year to split from it will head back quickly if she doesn't want to get pregnant again. How can one identify an individual humpback whale? The underside of the tail (called a fluke) is always unique, and is a distinguishing characteristic comparable to a human fingerprint. The fluke could be differently patterned in black and white, and it may have scars from a shark attack or a collision with a boat. Flukes are being photographed and researchers have access to a special database in which all the photographs are archived. This is called photo-identification. That gives us the opportunity to gather revealing information about a whale's preferred feeding grounds, migration routes, and behavior within a pod. How do humpback whales reproduce? Sexual maturity After approximately 5 to 8 years and after they have reached a length of approximately 35-40 feet, females as well as males are considered to have reached sexual maturity. Females are able to mate every 1-3 years after reaching their sexual maturity, but males reach their actual sexual maturity years later when they are strong enough to prevail over competitors. Gestation period After a gestation period of approximately 12 months, female humpbacks give birth, fluke first, to a calf nearly 14 feet long and 1 ton of weight. Calves are born into shallow, warmer waters around Hawaii, and a mother will carry her calf on her back to the surface to make its first spout right after birth. Nursing The mother nurses the calf for anywhere between 6 and 11 months. While feeding, mother and calf are close beneath the water surface so that both can breathe from time to time. The term nurse or suckle is actually not completely correct, since the milk is squirted by muscle power of the mother into the mouth of its calf. That could be up to 100-150 gallons of milk, which is very thick and fat like yoghurt, per day. In its first few months, the baby gains 1 pound of weight every 30 Minutes and grows up to 1 foot per month. Before its first birthday, the “little” humpback whale already eats solid food. At one year of age, it has doubled in weight and length. The mother guides the yearling to Hawaii the next winter, and splits from it there. How do humpback whales sing? For a long time, it was believed that whales cannot sing since they do not have functional vocal cords. Researchers believe that the sounds are produced by pushing one air stream in different directions within their respiratory tract. In the 1950's, their singing was discovered when the United States Navy experimented with hydrophones. From then on, their singing has been analyzed by scientists, who describe it like this: the whales go into a depth of between 45 & 130 feet and get into a certain position when they sing. They remain motionless with their head downward and their pectoral fins stretched. Kent Noonan, our engineer, made the following experiences: "There was a mother/baby/escort pod traveling toward me while I was out in my kayak with my hydrophone. The mother and baby veered to one side and swam by me underwater. The male swam directly under me only a few feet down and continued singing uninterrupted. I was listening as he approached and it became so loud I thought my ears would burst. I tore the headphones off and could still hear it very loud as he passed under me only about 8 feet down. What is known about their singing? We can distinguish two kinds of sound, the so-called "social sounds" and the classic "whalesongs" we are engaged with: social sounds These are short, quick sounds which can hardly be heard (or not heard at all!) under water with the human ear. These sounds can only be picked up with special hydrophones which would have to be close to the whales and pointed directly at them. The social sounds are used to communicate, especially when they travel slowly on the surface or when resting - but not when traveling at higher speeds. The majority of this kind of communication (85%) takes place between mothers and their calves according to Dr. Marsha Green, but another example may be whales within a pod communicating with each other. whalesongs It has been defined that only the humpback whale bulls are singing. Unlike a pop song with a melody, a whalesong is more like a string of different sounds in different pitches that can sound like humming, snoring, groaning, sighing or chirping. Similar to classical music, a whalesong consists of different themes which develop and build over the years. The whale songs can even be heard from a distance of 100 miles. The whales are singing mainly in their breeding grounds or on the way from or to their feeding grounds in cooler waters. There are no songs actually heard inside the feeding grounds, only sounds more like different commands within their special hunting technique. Perhaps we will be able to install a hydrophone in Alaska one day to learn more about that... Why do humpback whales sing? Although it is the best known and most studied large whale, nobody knows exactly why the humpback whale sings. As the songs are performed almost exclusively in the breeding grounds, researchers believe that singing and mating go together. But whether a male is trying to impress a female or get rid of competitors or show his social status still remains a secret. Another theory explains the singing as a kind of sonar to find other whales. Who knows? Maybe the whales are singing only for the pure joy of singing... What can we learn or use from their singing? It would be possible to identify individual singers by their voice pattern. Thus, one could observe the migration of one particular whale, which has been done in the past. Due to such a voice pattern, it was possible to identify a humpback whale which came to Hawaii one year and arrived in the warm waters of the Mexican coast the year after, which was previously regarded as impossible. Building up a world-wide monitoring system would make it possible to learn much more about the migration patterns of these giants. We at Whalesong hope to reach more scientists with our website who could use our broadcast for their work and then discuss their experiences with us. How long does a whale's song last? That varies greatly, and also depends on the age of the humpback. The song of a humpback develops over the years, starting with one theme and going up to 5-7 themes. As a point of reference, only 3-4 themes are used in classical music! In our observations, we could hear songs repeated again and again for up to three hours. Every now and then, the vocalizations are not recognizable as a song - they simply sound like different vocalizations. Do humpback whales sing the same song everywhere? The songs differ from population to population - the humpback whales of the North Pacific (Hawaii, Mexico, Japan) have a different song than, for example, the humpback whales of the South Pacific (Australia and the Islands of the South Pacific). Perhaps this is a version of different dialects? The songs in the individual regions change from season to season at nearly the same time, so that in the course of a season a complete new song develops. How far do the songs travel under water? Blue whales could once communicate from pole to pole - that means halfway around the world! But due to increasing noise pollution of the oceans, this is believed now to be impossible. Why do humpback whales breach? This behavior can be observed by all baleen whales, however the humpback whales are considered to be the acrobats in the family. They screw their body to two thirds or more out of the water, like turning on their own axle. With their powerful fluke they only need a few beats to screw themselves out of the water. One can observe such jumps mainly in the breeding areas, also in the waters of Hawaii! Therefore, it is assumed that this is a breeding behavior. Scientists also suppose this is a way to communicate or to get rid of parasites. No matter why they do it, it is an overwhelming spectacle! How good can humpback whales see? Humpback whales can see well beneath and above the water since the colors change under water. The eye is perfectly adapted: lachrymal glands produce a fatfilm which protects the eye from saltwater. The lens is elastic and can be adjusted to the different light conditions by muscle power. Humpback whales can see up to 400 feet under water. Can humpback whales see in color? Researchers at the Max-Planck-Institute for brain research in Frankfurt/Main, Germany, at the Alfred-Wegener-Institute in Bremen, Germany as well as at the Lund university in Sweden discovered back in April 2001 that whales and seals don't have blue cones in their eyes. They only have green cones and are therefore colorblind, as it is not possible to differentiate colors with only one kind of cone. The relatives of the whales and seals living on land, however, have both kind of cones. How long can humpback whales dive? Up to 45 minutes, but usually they dive 15-20 minutes depending on what they are doing. If the whales are within a so called "competition pod" (several full-grown males are trying to get the best position to the one female in the pod), they are travelling with faster speed, fighting, and breaching which costs them a lot of energy. Then they must come up to breathe after only 5-10 minutes. When the whales are avoiding loud vessel engines, researchers have observed them staying up to 45 minutes in the same position, coming up at the same spot they went down 45 minutes before. What is a spout? If a humpback whale is coming to the surface to breathe after a dive, it exhales air with a speed of more than 300 m/h. The whales are utilizing about 80% of their lung capacity of 2500 gallons - in comparison with humans, which utilize about 15% when breathing normally! Such a large amount of air at such a high speed forms a fountain 6 to 9 feet high, which is also called spout. The inhaled amount of oxygen is "stored" in their blood and to 40% in their muscles which enables the whales to dive as long as about 45 minutes without breathing. Do humpback whales sleep? It's not exactly sleep - it is more like doze. Humpbacks do not breath intuitively, which means they have to think of breathing (just like we human beings) under water. Nevertheless they have the ability to switch off half of their brain to relax. The other half of their brain is thinking of breathing, being aware of predators like Orcas or taking care of the baby if it is a mother. What do humpback whales feed on? They feed mainly on 'krill' (or small crustaceans which look like shrimp about 2 inches long) and on small fish such as herring, mackerel and cod . The name krill originates from the Norwegian word “kril” which means “feed for whales”. In the cold Arctic and Antarctic waters, these krill are found in large close swarms. Humpback whales eat up to a ton of feed per day when they are in cooler waters to build up a thick fat layer, called “blubber.” They live on this blubber during the winter months when they stay in warmer waters where less food is available. Do humpback whales eat the oceans empty? That is the argument of the Japanese lobbyists for commercial whaling, who claim that the whales will snatch away all the fish, but it is not true! Humpback whales are not able to eat big fish which we humans prefer (like tuna, perch or salmon) because their throat only has a diameter of only 6-8 inches! If a bigger fish came into its mouth, the humpback whale would have to spit it out to avoid suffocating. The only types of fish the humpback whales eat are herring or mackerel, and both kinds are not overfished yet. The greatest danger to the fish supply comes from us humans who are about to destroy their own food support by overfishing. How do humpback whales hunt it's prey? Humpback whales have developed different hunting techniques. Sometimes they simply swim through a large swarm of krill with an open mouth taking in tons of water and krill. In order to be able to take up such masses in the mouth, the throat grooves expand widely. The water, which is in the whale's closed mouth, is pressed with the tongue (which weighs up to two tons!) through the baleen plates and the small crustaceans are caught in the baleen plates (see also: What are baleen plates?) and then swallowed. A very specific technique of the Humpback whale can be observed: sometimes four to six whales unite in a group, diving down and circling a swarm of krill or fish. While circling and slowly emerging to the surface, the whales discharge air so that a net of bubbles develops. These bubbles force the prey in the center of the circle and w hat looks like a circle of ascending bubbles emerges, resulting in a spectacular event where several humpback whales with open mouth suddenly appear at one time taking up what they caught in this net of bubbles. What are baleen plates? Baleen plates are horny plates which hang down from both sides of the long upper jaw. The number and length of the baleen plates differs between different types of whales. Humpback whales have approximately 250-450 of them which grow to be about 2-3 feet long. They consist of material similar to human fingernails or the exterior of the horns of cattle. The baleen plates are arranged in lamella form and serve as a filter for food. The food gets caught at the bristle-like ends and is swallowed afterwards. |
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