VIEWS: 8 PAGES: 23 POSTED ON: 11/4/2010
Whales and Dolphins in Oman Dolphins and whales are abundant in the seas of Oman. They are protected by the government, and by a well-established tradition, fishermen rely on dolphins to locate tuna. The unique coastal structure makes Oman an ideal environment for all - dolphins and whales, and those who wish to enjoy their company. His majesty Sultan Qaboos of Oman realized early on that dolphins and whales are in need of human protection. He decreed laws on where and when fishing nets which pose possible dangers can be laid out and prohibited whaling. Both dolphins and tuna live on sardines. Tuna usually stay under the surface of the water while feeding and are therefore invisible to fishermen from a distance. Dolphins, however, keep much closer to the surface. Their bows and jumps can be seen from large distances and enable the fishermen to locate their prey: tuna. Fishermen in Oman therefore have an invested interest in the protection of dolphins. A major reason for the abundance of dolphins and whales in the coastal area around Muscat is the specific coastal structure. The drop off of the ocean bed that occurs on the edges of the continental shelf is very close to the shore of Muscat. Usually the first deep ocean bed drop-off is about 20 km away from the coast. In Oman the first drop-off is about 1km off the coast. The drop off brings marine life, which is normally found deep in the ocean, very close to the shore - an observer's delight. For more information on whales, dolphins and how to interact with them please see our whale and dolphin guide and our 'All you wanted to know about whales and dolphins in Oman' section. Tooth Cetaceans of Oman Spinner Dolphins Description: Spinner dolphins are usually about 2 m long and weigh from55 to 75 kg. Their bodies have a three-part colour pattern: Their backs are dark grey or black, their sides a pearl- grey and their chins and bellies are light grey or even white. Males are generally larger than the females. Spinner dolphins are slender in build and have long, thin beaks to which the distinct forehead slopes gently. Their beaks have a diagnostic black tip. Their dorsal fins vary in shape with age and geographical distribution. They are relatively small and can lean towards the fluke be curved or be completely triangular. The flippers are long and pointed and a dark stripe links them to the eyes and beak. Typical be haviour: In Oman Spinners travel in large groups of a thousand individuals or more. They are most often seen in schools of two hundred or less. They are often found in association with common dolphins, spotted dolphins and yellow fin tuna. Spinner dolphins can be very playful and curious and they often bow-ride. They are dramatically acrobatic and often perform somersaults, high spinning leaps and other aerial movements and can perform jumps up to three meters in the air. Spinning on their longitudinal axis is their trademark. Research has not come to any definite explanation this behaviour. By the means of splashing or landing on the water after the jumps the spinner dolphins might dislodge parasites on their bodies, they might use the jumps as a means for communication or just display playful behaviour through it. The groups found off Muscat are probably year round residents. Recognition at sea: Spinners can be identified by the shape of the dark area on the dorsal cape and the long black-tipped snout . From behind they might be mistaken for common dolphins, but they are smaller and their three-part colour pattern (tripartite) should enable easy differentiation. As their name implies spinning in the air is characteristic of this species. Habitat, distribution: Spinner dolphins are found both offshore and inshore in tropical and subtropical waters worldwide. They often occur within 2 or 3 kilometres off the shore in Oman and are frequently to be seen between Fahal Island and Bandar Khayran and often associate with common dolphins. Life span: 15-25 years. Predators: Sharks, false killer whales and killer whales, tuna fisheries. Estimated curre nt population worldwide: Unknown. An Omani Spinner Dolphin? In the Muscat area there have been sightings of groups of spinner dolphins that seem smaller, darker and less inclined to spin that the more typical tripartite individuals. They often have pink bellies, a feature that confuses them with juveniles of the more typical form. These dolphins bear some resemblance to dwarf spinner dolphins of the tropical and subtropical Atlantic. It is unclear yet whether these dolphins represent a separate population or even race, or are just a morphological variation. Common Dolphins Description: Common dolphins are fine, slender and streamlined in build. They can be anything from 1,7 to 2,6 meters in length and usually weigh less than 75kg. Males are slightly larger than females. Depending on the geographical location, common dolphins can have a long or a short beak. Although the common dolphin might vary in size and shape, it is easily recognizable a crisscross, hourglass colour pattern. The back is dark brown, black, grey or purplish from the top of the head to the tail and takes on the shape of a 'V' on the flanks below the dorsal fin. Behind the dorsal fin the flanks are a light grey and forward of the dorsal fin they are a creamy white. Its belly is a paler white and extends higher up the flanks than in most other dolphins. The tail is grey and darkens into black at the flukes. Around the eyes the common dolphin has large dark circles, which are connected by a dark line, which runs across the beak. Another black stripe runs from the flippers to the middle of the lower jaw. The dorsal fin of the common dolphin is tall and triangular with a pointed tip. It is located near the middle of the back and is black- to-light grey in colour with a black border. The flippers are long, thin and slightly curved. The flukes are thin, concave and pointed at the tips with a slight medial notch. Typical be haviour: Common dolphins are very social. They have been reported in groups of many thousands, although units of 10-500 are more usual. Occasionally common dolphins swim with other species of dolphins such as bottlenose dolphins, spinner dolphins or spotted dolphins. They are a fast swimming and active species and often perform aerial movements at the surface: They bow-ride, breach, somersault, flipper-slap and lob-tail and tail-slap. In Oman multiple jumps of multiple dolphins are common, often in spectacular synchrony. They are highly vocal and can often be heard above the water as they play. They often bow-ride boats. Recognition at sea: Common dolphins can be identified by their colour pattern. When in mixed groups the common dolphins tend to stay at the outskirts of the group. Habitat, distribution: Common dolphins are found in warm temperate, subtropical and tropical waters worldwide. They apparently prefer water temperatures ranging from 10 to 28 degrees centigrade. They can be seen fairly regularly in the coastal and near-shore area of Muscat. They generally inhabit the entire coast of Oman. Common dolphins do not seem to migrate. In some areas they are present all year round. Life span: 30 years. Estimated curre nt population worldwide: Unknown. Pantropical Spotted Dolphin Description: The pantropical spotted dolphin is a small species with a slender, but robust body and a long narrow beak. It can weigh from 90 -115 kg and can reach 2,4 meters in length. They have a dark grey dorsal cape and pale grey undersides. In between these two areas they may have a grey zone on their flanks. Their dark areas are covered with light spots and their light areas are covered with dark spots. Young animals might have no spots at all though. Their lips can be white, although they sometimes have dark spots. A black patch circles their eye. Their dorsal fins are curved and located at about half their body length. Typical be haviour: Schools of pantropical spotted dolphins range from a few individuals to thousands of animals. In Oman they mix with common and spinner dolphins. Although they do not spin, they are acrobatic animals, and may bow-ride, leap to great heights and lob-tail. Recognition at sea: The pantropical spotted dolphin can be distinguished from the spinner dolphin by its spots, shorter beak and colour pattern. In Oman the pantropical spotted dolphin is slightly larger and stockier than the spinner dolphin. Habitat, distribution: Pantropical Spotted dolphins are found worldwide in deep tropical and subtropical waters. They are seen infrequently in the Muscat area of Oman. Life span: Approximately 45 years. Predators: Sharks, killer whales, tuna, trawlers. Estimated curre nt population worldwide: Unknown. Striped Dolphins Description: Striped dolphins have slender bodies with narrow heads and long beaks. They can grow up to 2,5 m and weigh up to 160 kg. Striped dolphins are bluish grey and white in colour. Some of them have pink bellies. The flanks are pale grey, the bellies pink-white, and the flippers black. As the name implies they have a number of dark stripes on their body, running from the eye to the anus and to the back. they often have a dark patch around the eye. the markings vary from individual to individual and possibly between groups of striped dolphins of different geographical distribution. Their foreheads slope smoothly down to their long beaks, which are separated from their foreheads by a crease. Their dorsal fins are tall and rounded. Their flippers and tail flukes are small and slender. Typical be haviour: Striped dolphins move in groups of 100 to 500 individuals although there have been sightings of large gatherings of up to a few thousand. They are a very active species and are very fas t swimmers sometimes reaching speeds of 8 to 14 km per hour. They often jump high above the surface, do somersaults forwards and backwards and bowride. They often dive for 10 minutes while feeding. Some groups of striped dolphins are known to migrate, while others seem to be resident in certain areas. Recognition at Sea: This dolphin lives in deep tropical, subtropical and warm temperate waters worldwide off- and inshore. Habitat, distribution: This species occurs in warm temperate and tropical waters offshore worldwide. They are likely to be seen off Oman. Life span: Approximately 50 to 60 years. Predators: Sharks, killer whales, false killer whales, pygmy killer whales. Estimated curre nt population worldwide: Unknown. Rough Toothed Dolphin Description: This species has a robust body, similar to the bottlenose dolphin, and can reach up to 2 - 2.5 m in length and weigh up to 150 kg in adulthood. The body is streamlined with a forehead that slopes gently to the long beak. The dolphins derive their name from the rough texture of their teeth, which have fine, vertical grooves on them. The rough toothed dolphin has unusually large flippers and flukes. Rough toothed dolphins are dark grey to bluish black on the back and light grey on the undersides, flanks and the tail. Lips and jaws are white as are the scars and scratches they have from shark attacks. Typical be haviour: Little is known about this species. Rough toothed dolphins usually swim in groups of 10 to 50 individuals. However, groups can be as large as 100 animals. This species mixes with other dolphin species. They do not bow-ride often, but are well known for their "surfing" behaviour during which the dolphins swim at a high speed with their chins above the surface. In captivity this species produce offspring with bottlenose dolphins. In the wilderness these hybrids are rare, but have been observed too. Recognition at Sea: Rough toothed dolphins can be mistaken for spotted, spinner and bottlenose dolphins. However, their head is very distinctive. Habitat, distribution: Rough toothed dolphins occur in deep tropical, subtropical and warm temperate waters offshore worldwide. Life span: Unknown. Estimated curre nt population worldwide: Unknown. Bottle Nosed Dolphins Description: These dolphins have gained large popularity due to the television series 'Flipper'. They are the largest of the dolphins and have highly variable, broad dorsal fins. Some individuals in Oman reach 3 m in length and can weigh from 90 - 600 kg. Other physical characteristics can vary: Their dorsal surfaces can vary in colour from dark blue to brown- grey, and usually fade to a pale grey at the flanks. Their backs are white-pink. The tips of the snouts are usually white. The tail flukes and the edges of the flippers are grey-black in colour. There can be dark lines reaching from melon to eye and eye to flipper. However, sometimes bottlenose dolphins display entirely different colour patterns. Ochre brown individuals have been seen near Bandar Khayran. Larger adults often bear white or pinkish scars from fights with other individuals. The bottle-shaped beak can be rather short and slender or broader and more stubby depending on its body size. Their heads are fairly robust with rounded foreheads, also called 'melon'. The beaks and melons are separated by a clear crease. Typical be haviour: Bottlenose dolphins have been reported individually, in groups of 10 -100 inshore and of several hundreds offshore. In Oman they are usually to be seen in groups of about 10-50 individuals. They are fast, powerful swimmers, acrobatic and playful in nature and often bow- ride and leap along vessels. Recognition at Sea: Bottlenose dolphins are not likely to be confused with other species of dolphins. They are bulkier and usually darker in colour than Indo-pacific humpback dolphins. Their snouts are shorter and melons more defined than those of rough-toothed dolphins. Habitat, distribution: Bottlenose dolphins can be found in cold temperate and tropical seas worldwide. Preferring waters of less than 30 m in depth, they occur regularly in coastal waters and some populations might even migrate in response to changing environmental conditions. They are fairly common around Oman and are likely to be seen close to shore anywhere along the coast. Both, the bottlenose dolphin and the Indo-pacific humpback dolphin are the species most likely to be seen from land in Oman. Their apparent absence from the Musandam area is interesting and open to speculation. Life span: Bottlenose dolphins can live for up to 40 years. Estimated curre nt population worldwide: Unknown, but locally common. Dwarf sperm Whale Description: The dwarf sperm whale is the smallest of all whales. Both sexes can reach a length of up to 2,7 m and weigh up to 270 kg. It resembles the pygmy sperm whale but its snout is even more blunt and square, and its dorsal fin is larger. It has a porpoise- like form, with a blowhole positioned on the left side of the forehead, and a shark- like mouth with large, sharp, curved teeth in the lower jaw. Occasionally, small non-functional teeth occur in the upper jaw. Its colour is bluish- grey with a pinkish-white belly, which may have pink or purple spots. Typical be haviour: Dwarf sperm whales are often seen in groups of less than ten animals. Pods consist mostly of females, calves and sexually immature males. Their blow is low and indistinct. They are reported to be fairly passive animals, which often float around on the surface of the water close to shore for 15 to 20 minutes at a time. They are shy and typically avoid boats. If startled, dwarf sperm whales give off a reddish- brown fluid before diving. Recognition at Sea: Dwarf sperm whales resemble pygmy sperm whales in size, stature and colour and behaviour and are easily confused with them. They might also be mistaken for Risso's dolphins, pygmy killer whales or melon-headed whales. Habitat, distribution: Dwarf sperm whales live in both tropical and temperate seas. They are often sighted in coastal waters and have been seen on several occasions near Bandar Jissah. Although dwarf sperm whales spend most of their time at the surface of the water near the shore, they search for food such as small squid at great depths. Life span: Unknown. Estimated curre nt population worldwide: Unknown. Indo-Pacific Humpback Dolphin Description: Indo-pacific humpback dolphins can grow up to approximately 2.8 meters in length and weigh about 290 kg in weight. They are brownish-grey in colour, with a lighter belly, which is sometimes pink. The belly can be speckled and sometimes bears scars from shark bites. These dolphins have robust bodies with long, narrow beaks and white tipped jaws, large melons and well-rounded flippers. The dorsal fin rises from a fleshy hump and is often very prominent. They have unique way of surfacing in that its beak always emerges first. Their tail stocks are thick and have distinct keels. Typical be haviour: Indo-pacific humpback dolphins are generally found in small groups of between 2 and 7 individuals. Groups can be as large as 25 animals and have sometimes been as large as 100 individuals in Oman.. They are mostly found in shallow coastal water of up to 15 meters in depth where they feed. They tend to be shy and sedate, and are not easily approached by boat or underwater. Recognition at Sea: Indo-pacific humpback dolphins are easily identified by the distinctive hump on their backs and their small backward curving dorsal fins. Their white tipped jaws are often clearly visible when they surface. The shape of their heads resembles that of the bottlenose dolphin, but their snouts are usually more elongate and their foreheads less distinct. Habitat, distribution: Indo-pacific humpback dolphins live in the shallow coastal waters of the Indian and western Pacific Oceans. They prefer water of less than 20 m in depth with shallow banks and embayment, river channels and muddied waters. Off the coast of Oman they are one of few species, which are best seen from land. They have a curious and unexplained distribution, occurring around Musandam and south of Ra's al Hadd, but not in between, therefore you are unlikely to see them in the Muscat area. Life span: Unknown. Estimated curre nt population worldwide: Unknown. Risso's Dolphin Description: Risso's dolphins measure between 2.8-4 m in length and weigh up to 500 kg. Males are slightly longer than females. Risso's have robust bodies that become fairly slender behind the tall, curved and pointed dorsal fin. They have been described as tadpole- shaped. Their heads are blunt with large melons, lacking distinct beaks. Their mouths slant upwards. The flippers are long, narrow and curved. The dorsal fin is set at the mid-point of the body. The tail flukes are dark and broad. Risso's are dark brown or black with numerous white scratches and scars, which give the animal a lighter colour with age, since those scratches and scars accumulate with age. Fins, flippers and flukes are often a darker grey than the body. Their face is pale grey and on their bellies they have a white pattern. Typical be haviour: Risso's dolphins are usually found in groups of 3 to 50 animals, but groups might be much larger (500). Their behaviour towards other Risso's is quite rough. They slap, splash and might strike other individuals and may account for the heavy scarring. They are acrobatic and often spy-hop and bow-ride or roll on the surface. Being a fast moving species they breach, spy-hop and bow-ride often. Risso's dive deep for 10 minutes or more and feed on squid. Recognition at Sea: Risso's dolphin is quite easy to recognize at sea due to their distinctive colour pattern and blunt heads. At a distance they might be confused with bottlenose dolphins, but their dorsal fin is taller and they are lighter in colour than bottlenose dolphins. False killer whales might bear some resemblance to them, but they lack the distinctive colour pattern. Habitat, distribution: Risso's dolphins occur in tropical and temperate seas offshore and occasionally inshore worldwide. Risso's are most commonly seen well offshore in Oman, though large groups of them have also been observed near Muscat. Life span: At least 20 years. Predators: Killer whales, sharks and possibly false killer whales Estimated curre nt population worldwide: At least 80-90,000. Cuvier's Beaked Whale Description: Cuvier's beaked whales have slender, medium sized bodies, which can be up to 7 m in length. They have a shorter upper jaw than lower, in which males have two teeth, which are clearly visible. In females these teeth are hidden in the gums. The protruding jaw however creates the unusual sloping forehead by which this whale can be identified. The small dorsal fin is placed far down the body and the flukes are small. Cuvier's beaked whales are usually brown, often with darker backs and lighter heads and bellies in Oman. In other areas of the world the whale can be grey or even bluish. They are marked by scars and oval spots, which are often caused by other individuals. Typical be haviour: Little is known about this species since Cuvier's beaked whales are shy and keep away from boats and humans. Most of the information available is gathered from stranded individuals. If observed in the wild, Cuvier's beaked whales mostly move in groups of 2 - 10 individuals. These whales make deep dives, lasting up to 30 minutes, to find prey. Recognition at Sea: This whale is unlikely to be confused with any other whale due to its sloping forehead and protruding lower jaw. Habitat, distribution: Cuvier's beaked whales live in all oceans worldwide. However, they have rarely been observed in Oman. Life span: Unknown. Estimated curre nt population worldwide: Unknown. False Kille r Whales Description: False killer whales are large and lean. They are about 4,5 to 6 m long and weigh from 1 to 2 tons. Females are slightly smaller than males. False killer whales have round heads and no beak. The upper jaws overhang the lower jaws and their mouths are curved upwards as if in a smile. From behind the eye a crease leads to the tip of the head. Their flippers are located near the head and are fairly short, narrow and curved in a way, which resembles a bent elbow. Their dorsal fins are located centrally and have rounded tips. The flukes are small in relation to the body. Their body colour is grey or black, except for occasional lighter grey or white marks on the head and throat. Typical be haviour: False killer whales form herds of 10 to several hundreds of animals. They are social and often associate with other kinds of dolphins. They are fast swimmers, are playful and often bow-ride, breach, lobtail and jump so that the entire body is lifted out of the water. They frequently open their mouths so that entire rows of massive teeth are visible. Often large numbers of False Killer whales strand. Recognition at Sea: False killer whales can be mistaken for pygmy killer whales and pilot whales, but the size and shape of their heads and flippers differ. Habitat, distribution: False killer whales live in all oceans of the world. They prefer deep tropical and subtropical and warm waters, although some animals have been seen in cold waters. They occur mainly in deep waters. Life span: Unknown. Estimated curre nt population worldwide: Unknown. Killer Whales Description: The killer whale is the largest and most powerful member of the dolphin family. It can reach ten meters in length and weigh up to 10 tons. Killer whales have a stocky body, with a rounded head and an indistinct beak. There are 10-12 pairs of large teeth in each jaw. One of their most distinct features is the large dorsal fin situated in the middle of the back. In males this fin can be up to 1.8 m high. In females the fin is only about half that size and more rounded. Females are considerably smaller than males. Their flippers are large, broad, rounded and paddle shaped and are especially well noticeable when the whale leaps or spy hops. They can be up to 1/5 of the body length in males. The tail flukes are concave and often have pointed tips. They are separated by a deep- notch. Killer whales have a striking black and white colour combination although uniform black or white animals have been seen. Typical be haviour: Killer whales live and travel in extended family groups of up to 100 animals. Family groups usually consist of between 3- 25 individuals. These groups are called pods and consist of adult females, juveniles, calves and adult males with a highly developed social hierarchy. These pods are stable from one generation to the next and its members usually stay together for life. Killer whales are acrobatic. They frequently breach, jump, slap their tails and surf. Killer whales are inquisitive and approachable. Young whales are playful and use objects such as seaweed for their amusement. Within the group there is little aggression. Killer whales rub against each other or hard surfaces for comfort and to remove dead skin. Mass strandings are rare, but have been known to occur. Different groups vary in their vocalisations. Recognition at Sea: Killer whales are easily identified by their colour pattern and their huge triangular dorsal fin. The female and juvenile can be confused with Risso's dolphin and the false killer whale when at a distance.Their blow is a low foggy cloud. Habitat, distribution: Killer whales inhabit all oceans and seas worldwide. They are very adaptable to almost any conditions and appear in both the open sea and coastal waters. They occur less in waters furthest from land and those, which are not very productive. The degree of ice cover limits polar distribution and they do not normally migrate from warm to cold waters. Killer whales are occasionally seen in the area around Oman. Food and Feeding: Killer whales have a reputation for being fearsome and versatile predators. They are known as the 'Wolves of the Sea'. Their diet is very variable consisting of seals, fish, turtles, squid, sea-birds and other whales. Killer whales often hunt in teams, which improves their hunting success. Hunting normally occurs during dives of less than 100 m, with members of the pod cooperating in keeping the prey at or near the surface. Fish might be forced into areas where they can be captured more easily. Migrating killer whales primarily feed on marine mammals, whereas resident whales feed mainly on fish. However, killer whales have been seen to associate with other mammals such as Minke whales and other small cetaceans with no predatory intent by the killer whales and no apparent fear or intent of flight by the other cetaceans. Life span: Between 60-90 years. Females have a longer lifespan than males. Estimated curre nt population worldwide: At least 1,000,000. Sperm Whale This page is under construction and will be online shortly. Baleen Cetaceans of Oman Baleen cetaceans (Myscticetes) have baleen and lacking teeth. The baleen are horny plates hanging from the whale's upper jaw. This baleen consists of a fibrous material similar to our fingernails .The baleen whales are filter feeders, using baleen plates to sieve out small planktonic organism from the sea. It is curios that baleen whale, the largest animals in the sea, feed on some of the smallest. They sizes vary from 6 m , pygmy right whale to 30m long blue whale that weighs up to 200 tonnes and the largest animal ever to have lived. A baleen whale has a symmetrical skull and a double blowhole. Some baleen whales are thought to be more than 100 years old, so we may think of them having life-spans roughly as humans. There are about 11 species of baleen whales. Minke Whale Description: Minke whales are the smallest and most streamlined of the baleen whales. They reach about 8-9 meters in length and can weigh up to 10 tons. Females are slightly larger and heavier than males. Minke whales are dark grey on their backs and lighter on their bellies and their flanks might be lighter coloured as well. They have a characteristic white stripe on each flipper (that is absent on the southern Minke whales) whose size and shape varies individually. They have two blowholes like all baleen whales behind which there might be grey markings. The snout of minke whales is narrow, triangular, and pointed, hence their nicknames "sharp- headed finner" and "little piked whale", and contains 220 to 230 baleen plates. They have about 50 to 70 throat grooves. Along the middle of their rostrum they have a single ridge. They have long flippers which can be up to 1/8 of the Minke's body size and a small dorsal fin in the latter third of their bodies. This fin is relatively tall, pointed and upright. Their flippers are short and pointed too. Their flukes are broad. Typical be haviour: Minke whales travel singly or in small pods of 2 to 4 individuals, but when krill is abundant they can be found in large groups of hundreds of individuals. They are very curious and approach boats. They are fast swimmers, and can reach over 34 kmh in bursts. They can leap completely out of the water when breaching. Minke whales dive for up to 20 minutes, but don't show their flukes before going underwater. Their blow is low and not very obvious even in calm conditions. The migration of Minke whales is less well defined than that of other baleen whales. They seem to undergo some migration, but possibly not over long distances. Recognition at Sea: whales can be identified by the white band or patch on their flippers. Habitat, distribution: Minke whales occur in all tropical, temperate and polar waters worldwide. They seem to prefer cooler waters over tropical ones, but are widely distributed in all seasons. Although they are not coastal, they rarely venture further than 170 km away from the coast. They do enter bays, fjords and inlets. Life span: At least 20 years. Predators: Killer whales. Estimated curre nt population worldwide: Estimates range from 300,000 to 800,000. Bryde's Whale Description: Bryde's whales can grow to 15 meters and weigh up to 20 tons. Those seen in Oman usually reach a length of about 13 m. They are mottled bluish- grey and might have scars from cookie- cutter shark bites. Their bodies and throats are white. They are slender built with broad flat, 'V' shaped heads. There are three ridges leading from the blowhole to the tip of the snout. Their dorsal fin is about 50 cm high, sickle shaped and has a pointed tip. It is located in the last third of the body. The flippers are small. Recognition at Sea: Bryde's whales can be identified by the three ridges which run from the blowhole to the tip of the snout. Other whales like the Minke, blue whale, and fin whales only have one ridge. Their blow is about 4 m tall and very thin. Habitat, distribution: Bryde's whales occur in all warm temperate and tropical waters worldwide. Bryde's whales do not seem to make long migrations. There is speculation that Oman might be a breeding ground since these whales are mostly seen in pairs of mother and calf in the Muscat area between March and April. Life span: Unknown. Estimated curre nt population worldwide: Approximately 90,000. Sei Whale Description: Sei whales have relatively slender bodies which are between 12 and 15 m long. Males are slightly smaller than females. They are dark bluish grey with white bellies. Their head is long and narrow with a pointed snout. On each side of the mouth these whales have 300-380 plates of baleen and they have about 32-60 throat grooves. Their dorsal fin is relatively small, sickle shaped and located near the fluke. Also their flippers and flukes are relatively small. Sei whales are amongst the fastest whales in the sea. Their throats have 38 to 56 deep grooves. Typical Behaviour: Very little is known about the social system of sei whales. Usually they are found in groups ofup to 5 whales. Sei whales are amongst the fastest of all whales and dolphins. They swim at up 50 kmh. Recognition at Sea: Sei whales have a dorsal fin that is taller than that of BrydeÕs whales and they have a single, central ridge at the rostrum (while Bryde's whales have three). Habitat, distribution: These whales are found offshore in all oceans worldwide, except for the polar and tropical regions. In the summer sei whales can be found in temperate and subpolar regions and in the winter in subtropical waters. Life span: 50 to 70 years Estimated curre nt population worldwide: Endangered. 50, 000 to 70,000 Humpback Whale Description: Humpback whales are 11,5 to 20 meters long and weigh about 25 to 40 tons. Females are slightly larger and heavier than males. Humpback whales are black to blue-black in colour on the upper side and mottled black and white on the belly. Each whale has distinctive markings on it's fluke and flippers. These as well as the form of fluke, flippers and dorsal fin are highly individual in each animal and are useful for identification. These whales have robust bodies with very long flippers. The flippers and lower jaws are covered by raised bumps and lumps on which parasites may grow. The lumps on the lower jaw and head contain a stiff hair each which might provide the whales with a sense of touch. Humpback whales have relatively small dorsal fins located in the last third of the body. They vary in size and form from individual to individual. Their tail flippers are very long and their edges are crimped. Typical Behaviour: Humpback whales often occur in large, loose, unstable groups of 10 to 100 animals, but they might move in smaller units within these groups. Sightings are mostly of single or pairs of animals. When breeding males can show very aggressive behaviour towards other males in order to claim and maintain females. A feature of courting is 'singing'. The songs can vary from 10 minutes to days in length, with pauses only for breath. Humpbacks are very acrobatic and perform a variety of aerial and underwater movements like breaching, spy hopping, lob-tailing and tailslapping. Some Humpbacks in Alaska have been seen rolling over icebergs in play. Humpback whales swim at a maximum speed of 27 kmh, but usually move at 4 to 14 kmh. They can dive up 120 and 150 m deep and up to 30 minutes in length, but dives for less than 7 minutes are more common. recognition at sea: Humpbacks are not easily confused with any other species. They have a bushy blow, long flippers and raise their serrated flukes before diving. habitat, distribution: Humpback whales occur seasonally in all oceans worldwide. They can be found in shallow coastal areas from the tropics to the polar waters. All populations of Humpback whales undertake vast regular migrations between breeding and feeding grounds. There is a population in the Arabian Sea and Gulf of Oman, which may be resident all year round though. predators: Killer whales, sharks. Life span: Approximately 40 -95 years. estimated current population worldwide: Estimates vary between 5000 to 20 000 animals, vulnerable to extinction. Fin Whale Balaenoptera musculus description: Fin whales are the second largest animals. Adult fin whales can reach up to 27 m and weigh up to 80 tons. Females are slightly larger than males. Fin whales are dark grey to brownish black in colour on their backs and pale grey to white on the throat and belly. Behind their heads at the side they may be greyish-white. Their front baleen plates and their 50 to 100 throat grooves are white on the right side and dark grey on the left side. The flippers and flukes have a white underside. Fin whales bodies are very streamlined, but slightly rounder than that of blue whales. Their heads have two distinct blowholes and a ridge extending from the blowholes to the snout. Their head is 'V' shaped with a distinct snout. They have about 260-480 baleen plates on each side of the jaw. The dorsal fin varies in shape. It can be pointed or rounded, and also its angle is highly variable. It is located in the last third of the body. Extending from the dorsal fin to the fluke is a ridge which gives the whales their alternative name "Razorblade". The flippers are relatively slender, short and pointed. The flukes have a distinct notch in the middle. They are broad and slightly triangular. typical behaviour: Occur in groups of 3-20 whales, but there can be larger gatherings for feeding. Fin wales dive for 5 to 15 minutes to depth of 230 m. This is deeper than either blue or sei whales dive. Fin whales surface with their blowholes first. They sometimes breach clear of the water landing on the belly or side of their bodies and are fast swimmers capable of reaching 41 kmh. recognition at sea: Fin whales are difficult to distinguish from blue whales at sea. Blue whales heads have a uniform colour pattern , whereas fin whales don't. Fin whales heads are also narrower. Fin whales dorsal fins are larger in comparison to those of blue whales. habitat, distribution: Fin whales occur worldwide, but are most common in temperate waters and in the southern hemisphere. Like other baleen whales they are migratory animals. Recognition at Sea: Humpback whales can be distinguished from other baleen whales by their long flippers and their robust bodies. They can also be identified by the knobs they have on their snouts and heads. Their flukes are also easily recognisable by their colour pattern and serrated edges. Predators: Killer Whales. Life span: 85 to 90 years Estimated curre nt population worldwide: Locally common, about 5000 to 20000 animals. vulnerable to extinction. Fin Whale Description: Fin whales are the second largest animals. Adult fin whales can reach 27 m and weigh up to 80 tons. Females are slightly larger than males. Fin whales are dark grey to brownish black in colour on their backs and pale grey to white on the throat and belly. Their baleen plates and throat grooves are much paler on the right side and dark on the left side. The flippers and flukes have a white underside. Fin whales bodies are very streamlined, but slightly rounder than that of blue whales. Their heads have two distinct blowholes and a ridge extending from the blowholes to the snout. Their head is 'V' shaped with a distinct snout. They have about 260-480 baleen plates on each side of the jaw. The dorsal fin varies in shape. It can be pointed or rounded, and its angle is highly variable. It is located in the last third of the body. Extending from the dorsal fin to the fluke is a ridge which gives the whales their alternative name "Razorblade". The flippers are relatively slender, short and pointed. The flukes have a distinct notch in the middle. They are broad and slightly triangular. Typical Behaviour: Occur in groups of 3-20 whales, but there can be larger gatherings for feeding. Fin wales dive for 5 to 15 minutes to depths of over 500m. This is deeper than either blue or sei whales are known to dive. Fin whales surface with their blowholes first. They sometimes breach clear of the water landing on the belly or side of their bodies and are fast swimmers capable of reaching 41 kmh. Recognition at Sea: Fin whales are difficult to distinguish from blue whales at sea. Blue whales heads have a uniform colour pattern , whereas fin whales don't. Fin whales heads are also narrower and their dorsal fins larger in comparison to those of blue whales. Predators: Killer Whales. Habitat, distribution: Fin whales occur worldwide, but are most common in temperate waters and in the southern hemisphere. Like other baleen whales they are migratory animals. Life span: 85 to 90 years Blue Whale Description: Blue whales are not only the largest whales, but also the largest living animals and the largest animals known in the history of life. They reach a length of over 30 meters and weigh about 100 -120 tons. Females are slightly larger than males and animals in the southern hemisphere are larger than those in the northern. The largest recorded animal was 33 m long and the heaviest weighed 200 tons. Blue whale's bodies are slender and streamlined, but very broad and long. They have broad and flat heads and snouts which, when viewed from above, have a triangular shape with a flattened tip. About three- quarters of the way along the back they have a small dorsal fin which is about 0.4 m high and can vary in shape ranging from triangular to rounded. Their tail flukes are large and notched, and their flippers are long (up to 15 % of body length), slender and pointed. Their body colour is a dark blue-grey dorsally and lighter on the back. However, large variation has been reported ranging from mottled dark blue with few lighter spots to a very heavily mottled light blue. Their heads are uniformly blue but the back and sides are showing grey or white spots. The undersides often become covered with microorganisms which give the belly a yellowish tone. This has lead to the species nickname "sulphurbottom". The undersides of the flippers are light greyish blue to white. Each whale has about 540-790 coarse black baleen plates, each about 1 m in length. Typical Behaviour: Blue whales are usually encountered alone or in pairs (mother and calf). In areas of high food concentration larger groups have been reported. Occasionally they mix with fin whales. Blue whales swim at speeds ranging from 2 - 6.5 km per hour while feeding and 22 - 48 km per hour while travelling, migrating or when being pursued. With the speed of movement and the activity of the whale its blowing and diving patterns vary. They usually dive for short amounts of time ranging from 10 to 20 minutes. Dives of up to 30 minutes have been recorded. In contrast to Humpback whales, Blue whales lift their flukes only slightly as they begin a dive. Blue whales do not usually dive to more than 100 m depth where they feed, but they can dive to 500 m. They have occasionally been observed performing leaps. Blue whales are usually migratory, moving towards the poles in summer for feeding and back towards warmer waters in winter for breeding. Recognition at Sea: They have mottled skin pigmentation and are fast swimmers. They have a very tall and narrow blow (9m) and are often very large. Predators: Despite their size, there are documented cases of blue whales being attacked by pods of killer whales. Life span: Estimates reach from approximately 80 - 110 years. Estimated curre nt population worldwide: 500 - 5,000 animals. Endangered.
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